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4012 Commits (eirik/revert-vbus-gpio-factory-dts)

Author SHA1 Message Date
Arnd Bergmann ef3af3465a kasan: rework Kconfig settings
commit e7c52b84fb upstream.

We get a lot of very large stack frames using gcc-7.0.1 with the default
-fsanitize-address-use-after-scope --param asan-stack=1 options, which can
easily cause an overflow of the kernel stack, e.g.

  drivers/gpu/drm/i915/gvt/handlers.c:2434:1: warning: the frame size of 46176 bytes is larger than 3072 bytes
  drivers/net/wireless/ralink/rt2x00/rt2800lib.c:5650:1: warning: the frame size of 23632 bytes is larger than 3072 bytes
  lib/atomic64_test.c:250:1: warning: the frame size of 11200 bytes is larger than 3072 bytes
  drivers/gpu/drm/i915/gvt/handlers.c:2621:1: warning: the frame size of 9208 bytes is larger than 3072 bytes
  drivers/media/dvb-frontends/stv090x.c:3431:1: warning: the frame size of 6816 bytes is larger than 3072 bytes
  fs/fscache/stats.c:287:1: warning: the frame size of 6536 bytes is larger than 3072 bytes

To reduce this risk, -fsanitize-address-use-after-scope is now split out
into a separate CONFIG_KASAN_EXTRA Kconfig option, leading to stack
frames that are smaller than 2 kilobytes most of the time on x86_64.  An
earlier version of this patch also prevented combining KASAN_EXTRA with
KASAN_INLINE, but that is no longer necessary with gcc-7.0.1.

All patches to get the frame size below 2048 bytes with CONFIG_KASAN=y
and CONFIG_KASAN_EXTRA=n have been merged by maintainers now, so we can
bring back that default now.  KASAN_EXTRA=y still causes lots of
warnings but now defaults to !COMPILE_TEST to disable it in
allmodconfig, and it remains disabled in all other defconfigs since it
is a new option.  I arbitrarily raise the warning limit for KASAN_EXTRA
to 3072 to reduce the noise, but an allmodconfig kernel still has around
50 warnings on gcc-7.

I experimented a bit more with smaller stack frames and have another
follow-up series that reduces the warning limit for 64-bit architectures
to 1280 bytes (without CONFIG_KASAN).

With earlier versions of this patch series, I also had patches to address
the warnings we get with KASAN and/or KASAN_EXTRA, using a
"noinline_if_stackbloat" annotation.

That annotation now got replaced with a gcc-8 bugfix (see
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81715) and a workaround for
older compilers, which means that KASAN_EXTRA is now just as bad as
before and will lead to an instant stack overflow in a few extreme
cases.

This reverts parts of commit 3f181b4d86 ("lib/Kconfig.debug: disable
-Wframe-larger-than warnings with KASAN=y").  Two patches in linux-next
should be merged first to avoid introducing warnings in an allmodconfig
build:
  3cd890dbe2 ("media: dvb-frontends: fix i2c access helpers for KASAN")
  16c3ada89c ("media: r820t: fix r820t_write_reg for KASAN")

Do we really need to backport this?

I think we do: without this patch, enabling KASAN will lead to
unavoidable kernel stack overflow in certain device drivers when built
with gcc-7 or higher on linux-4.10+ or any version that contains a
backport of commit c5caf21ab0.  Most people are probably still on
older compilers, but it will get worse over time as they upgrade their
distros.

The warnings we get on kernels older than this should all be for code
that uses dangerously large stack frames, though most of them do not
cause an actual stack overflow by themselves.The asan-stack option was
added in linux-4.0, and commit 3f181b4d86 ("lib/Kconfig.debug:
disable -Wframe-larger-than warnings with KASAN=y") effectively turned
off the warning for allmodconfig kernels, so I would like to see this
fix backported to any kernels later than 4.0.

I have done dozens of fixes for individual functions with stack frames
larger than 2048 bytes with asan-stack, and I plan to make sure that
all those fixes make it into the stable kernels as well (most are
already there).

Part of the complication here is that asan-stack (from 4.0) was
originally assumed to always require much larger stacks, but that
turned out to be a combination of multiple gcc bugs that we have now
worked around and fixed, but sanitize-address-use-after-scope (from
v4.10) has a much higher inherent stack usage and also suffers from at
least three other problems that we have analyzed but not yet fixed
upstream, each of them makes the stack usage more severe than it should
be.

Link: http://lkml.kernel.org/r/20171221134744.2295529-1-arnd@arndb.de
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[arnd: rebase to v4.9; only re-enable warning]
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-25 11:05:55 +01:00
Eric Biggers d39838a556 509: fix printing uninitialized stack memory when OID is empty
[ Upstream commit 8dfd2f22d3 ]

Callers of sprint_oid() do not check its return value before printing
the result.  In the case where the OID is zero-length, -EBADMSG was
being returned without anything being written to the buffer, resulting
in uninitialized stack memory being printed.  Fix this by writing
"(bad)" to the buffer in the cases where -EBADMSG is returned.

Fixes: 4f73175d03 ("X.509: Add utility functions to render OIDs as strings")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-25 11:05:48 +01:00
Andrey Ryabinin 3c83fe52b5 lib/ubsan: add type mismatch handler for new GCC/Clang
commit 42440c1f99 upstream.

UBSAN=y fails to build with new GCC/clang:

    arch/x86/kernel/head64.o: In function `sanitize_boot_params':
    arch/x86/include/asm/bootparam_utils.h:37: undefined reference to `__ubsan_handle_type_mismatch_v1'

because Clang and GCC 8 slightly changed ABI for 'type mismatch' errors.
Compiler now uses new __ubsan_handle_type_mismatch_v1() function with
slightly modified 'struct type_mismatch_data'.

Let's add new 'struct type_mismatch_data_common' which is independent from
compiler's layout of 'struct type_mismatch_data'.  And make
__ubsan_handle_type_mismatch[_v1]() functions transform compiler-dependent
type mismatch data to our internal representation.  This way, we can
support both old and new compilers with minimal amount of change.

Link: http://lkml.kernel.org/r/20180119152853.16806-1-aryabinin@virtuozzo.com
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reported-by: Sodagudi Prasad <psodagud@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-17 13:21:20 +01:00
Andrew Morton 3f8130127c lib/ubsan.c: s/missaligned/misaligned/
commit b8fe1120b4 upstream.

A vist from the spelling fairy.

Cc: David Laight <David.Laight@ACULAB.COM>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-17 13:21:20 +01:00
Alexei Starovoitov a3d6dd6a66 bpf: introduce BPF_JIT_ALWAYS_ON config
[ upstream commit 290af86629 ]

The BPF interpreter has been used as part of the spectre 2 attack CVE-2017-5715.

A quote from goolge project zero blog:
"At this point, it would normally be necessary to locate gadgets in
the host kernel code that can be used to actually leak data by reading
from an attacker-controlled location, shifting and masking the result
appropriately and then using the result of that as offset to an
attacker-controlled address for a load. But piecing gadgets together
and figuring out which ones work in a speculation context seems annoying.
So instead, we decided to use the eBPF interpreter, which is built into
the host kernel - while there is no legitimate way to invoke it from inside
a VM, the presence of the code in the host kernel's text section is sufficient
to make it usable for the attack, just like with ordinary ROP gadgets."

To make attacker job harder introduce BPF_JIT_ALWAYS_ON config
option that removes interpreter from the kernel in favor of JIT-only mode.
So far eBPF JIT is supported by:
x64, arm64, arm32, sparc64, s390, powerpc64, mips64

The start of JITed program is randomized and code page is marked as read-only.
In addition "constant blinding" can be turned on with net.core.bpf_jit_harden

v2->v3:
- move __bpf_prog_ret0 under ifdef (Daniel)

v1->v2:
- fix init order, test_bpf and cBPF (Daniel's feedback)
- fix offloaded bpf (Jakub's feedback)
- add 'return 0' dummy in case something can invoke prog->bpf_func
- retarget bpf tree. For bpf-next the patch would need one extra hunk.
  It will be sent when the trees are merged back to net-next

Considered doing:
  int bpf_jit_enable __read_mostly = BPF_EBPF_JIT_DEFAULT;
but it seems better to land the patch as-is and in bpf-next remove
bpf_jit_enable global variable from all JITs, consolidate in one place
and remove this jit_init() function.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-31 12:55:56 +01:00
Randy Dunlap a780a72847 dynamic-debug-howto: fix optional/omitted ending line number to be LARGE instead of 0
[ Upstream commit 1f3c790bd5 ]

line-range is supposed to treat "1-" as "1-endoffile", so
handle the special case by setting last_lineno to UINT_MAX.

Fixes this error:

  dynamic_debug:ddebug_parse_query: last-line:0 < 1st-line:1
  dynamic_debug:ddebug_exec_query: query parse failed

Link: http://lkml.kernel.org/r/10a6a101-e2be-209f-1f41-54637824788e@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Jason Baron <jbaron@akamai.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-14 09:28:22 +01:00
Stephen Bates a77c116075 lib/genalloc.c: make the avail variable an atomic_long_t
[ Upstream commit 36a3d1dd4e ]

If the amount of resources allocated to a gen_pool exceeds 2^32 then the
avail atomic overflows and this causes problems when clients try and
borrow resources from the pool.  This is only expected to be an issue on
64 bit systems.

Add the <linux/atomic.h> header to pull in atomic_long* operations.  So
that 32 bit systems continue to use atomic32_t but 64 bit systems can
use atomic64_t.

Link: http://lkml.kernel.org/r/1509033843-25667-1-git-send-email-sbates@raithlin.com
Signed-off-by: Stephen Bates <sbates@raithlin.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reviewed-by: Daniel Mentz <danielmentz@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-14 09:28:22 +01:00
Eric Biggers 44acfcb6dd ASN.1: check for error from ASN1_OP_END__ACT actions
commit 81a7be2cd6 upstream.

asn1_ber_decoder() was ignoring errors from actions associated with the
opcodes ASN1_OP_END_SEQ_ACT, ASN1_OP_END_SET_ACT,
ASN1_OP_END_SEQ_OF_ACT, and ASN1_OP_END_SET_OF_ACT.  In practice, this
meant the pkcs7_note_signed_info() action (since that was the only user
of those opcodes).  Fix it by checking for the error, just like the
decoder does for actions associated with the other opcodes.

This bug allowed users to leak slab memory by repeatedly trying to add a
specially crafted "pkcs7_test" key (requires CONFIG_PKCS7_TEST_KEY).

In theory, this bug could also be used to bypass module signature
verification, by providing a PKCS#7 message that is misparsed such that
a signature's ->authattrs do not contain its ->msgdigest.  But it
doesn't seem practical in normal cases, due to restrictions on the
format of the ->authattrs.

Fixes: 42d5ec27f8 ("X.509: Add an ASN.1 decoder")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-14 09:28:12 +01:00
Eric Biggers 608845ad49 ASN.1: fix out-of-bounds read when parsing indefinite length item
commit e0058f3a87 upstream.

In asn1_ber_decoder(), indefinitely-sized ASN.1 items were being passed
to the action functions before their lengths had been computed, using
the bogus length of 0x80 (ASN1_INDEFINITE_LENGTH).  This resulted in
reading data past the end of the input buffer, when given a specially
crafted message.

Fix it by rearranging the code so that the indefinite length is resolved
before the action is called.

This bug was originally found by fuzzing the X.509 parser in userspace
using libFuzzer from the LLVM project.

KASAN report (cleaned up slightly):

    BUG: KASAN: slab-out-of-bounds in memcpy ./include/linux/string.h:341 [inline]
    BUG: KASAN: slab-out-of-bounds in x509_fabricate_name.constprop.1+0x1a4/0x940 crypto/asymmetric_keys/x509_cert_parser.c:366
    Read of size 128 at addr ffff880035dd9eaf by task keyctl/195

    CPU: 1 PID: 195 Comm: keyctl Not tainted 4.14.0-09238-g1d3b78bbc6e9 #26
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-20171110_100015-anatol 04/01/2014
    Call Trace:
     __dump_stack lib/dump_stack.c:17 [inline]
     dump_stack+0xd1/0x175 lib/dump_stack.c:53
     print_address_description+0x78/0x260 mm/kasan/report.c:252
     kasan_report_error mm/kasan/report.c:351 [inline]
     kasan_report+0x23f/0x350 mm/kasan/report.c:409
     memcpy+0x1f/0x50 mm/kasan/kasan.c:302
     memcpy ./include/linux/string.h:341 [inline]
     x509_fabricate_name.constprop.1+0x1a4/0x940 crypto/asymmetric_keys/x509_cert_parser.c:366
     asn1_ber_decoder+0xb4a/0x1fd0 lib/asn1_decoder.c:447
     x509_cert_parse+0x1c7/0x620 crypto/asymmetric_keys/x509_cert_parser.c:89
     x509_key_preparse+0x61/0x750 crypto/asymmetric_keys/x509_public_key.c:174
     asymmetric_key_preparse+0xa4/0x150 crypto/asymmetric_keys/asymmetric_type.c:388
     key_create_or_update+0x4d4/0x10a0 security/keys/key.c:850
     SYSC_add_key security/keys/keyctl.c:122 [inline]
     SyS_add_key+0xe8/0x290 security/keys/keyctl.c:62
     entry_SYSCALL_64_fastpath+0x1f/0x96

    Allocated by task 195:
     __do_kmalloc_node mm/slab.c:3675 [inline]
     __kmalloc_node+0x47/0x60 mm/slab.c:3682
     kvmalloc ./include/linux/mm.h:540 [inline]
     SYSC_add_key security/keys/keyctl.c:104 [inline]
     SyS_add_key+0x19e/0x290 security/keys/keyctl.c:62
     entry_SYSCALL_64_fastpath+0x1f/0x96

Fixes: 42d5ec27f8 ("X.509: Add an ASN.1 decoder")
Reported-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-14 09:28:12 +01:00
Eric Biggers 443d26a6f7 lib/mpi: call cond_resched() from mpi_powm() loop
commit 1d9ddde12e upstream.

On a non-preemptible kernel, if KEYCTL_DH_COMPUTE is called with the
largest permitted inputs (16384 bits), the kernel spends 10+ seconds
doing modular exponentiation in mpi_powm() without rescheduling.  If all
threads do it, it locks up the system.  Moreover, it can cause
rcu_sched-stall warnings.

Notwithstanding the insanity of doing this calculation in kernel mode
rather than in userspace, fix it by calling cond_resched() as each bit
from the exponent is processed.  It's still noninterruptible, but at
least it's preemptible now.

Do the cond_resched() once per bit rather than once per MPI limb because
each limb might still easily take 100+ milliseconds on slow CPUs.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-30 08:39:01 +00:00
Eric Biggers 8ea52a683f KEYS: fix NULL pointer dereference during ASN.1 parsing [ver #2]
commit 624f5ab872 upstream.

syzkaller reported a NULL pointer dereference in asn1_ber_decoder().  It
can be reproduced by the following command, assuming
CONFIG_PKCS7_TEST_KEY=y:

        keyctl add pkcs7_test desc '' @s

The bug is that if the data buffer is empty, an integer underflow occurs
in the following check:

        if (unlikely(dp >= datalen - 1))
                goto data_overrun_error;

This results in the NULL data pointer being dereferenced.

Fix it by checking for 'datalen - dp < 2' instead.

Also fix the similar check for 'dp >= datalen - n' later in the same
function.  That one possibly could result in a buffer overread.

The NULL pointer dereference was reproducible using the "pkcs7_test" key
type but not the "asymmetric" key type because the "asymmetric" key type
checks for a 0-length payload before calling into the ASN.1 decoder but
the "pkcs7_test" key type does not.

The bug report was:

    BUG: unable to handle kernel NULL pointer dereference at           (null)
    IP: asn1_ber_decoder+0x17f/0xe60 lib/asn1_decoder.c:233
    PGD 7b708067 P4D 7b708067 PUD 7b6ee067 PMD 0
    Oops: 0000 [#1] SMP
    Modules linked in:
    CPU: 0 PID: 522 Comm: syz-executor1 Not tainted 4.14.0-rc8 #7
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.3-20171021_125229-anatol 04/01/2014
    task: ffff9b6b3798c040 task.stack: ffff9b6b37970000
    RIP: 0010:asn1_ber_decoder+0x17f/0xe60 lib/asn1_decoder.c:233
    RSP: 0018:ffff9b6b37973c78 EFLAGS: 00010216
    RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000000000000021c
    RDX: ffffffff814a04ed RSI: ffffb1524066e000 RDI: ffffffff910759e0
    RBP: ffff9b6b37973d60 R08: 0000000000000001 R09: ffff9b6b3caa4180
    R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000002
    R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
    FS:  00007f10ed1f2700(0000) GS:ffff9b6b3ea00000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 0000000000000000 CR3: 000000007b6f3000 CR4: 00000000000006f0
    Call Trace:
     pkcs7_parse_message+0xee/0x240 crypto/asymmetric_keys/pkcs7_parser.c:139
     verify_pkcs7_signature+0x33/0x180 certs/system_keyring.c:216
     pkcs7_preparse+0x41/0x70 crypto/asymmetric_keys/pkcs7_key_type.c:63
     key_create_or_update+0x180/0x530 security/keys/key.c:855
     SYSC_add_key security/keys/keyctl.c:122 [inline]
     SyS_add_key+0xbf/0x250 security/keys/keyctl.c:62
     entry_SYSCALL_64_fastpath+0x1f/0xbe
    RIP: 0033:0x4585c9
    RSP: 002b:00007f10ed1f1bd8 EFLAGS: 00000216 ORIG_RAX: 00000000000000f8
    RAX: ffffffffffffffda RBX: 00007f10ed1f2700 RCX: 00000000004585c9
    RDX: 0000000020000000 RSI: 0000000020008ffb RDI: 0000000020008000
    RBP: 0000000000000000 R08: ffffffffffffffff R09: 0000000000000000
    R10: 0000000000000000 R11: 0000000000000216 R12: 00007fff1b2260ae
    R13: 00007fff1b2260af R14: 00007f10ed1f2700 R15: 0000000000000000
    Code: dd ca ff 48 8b 45 88 48 83 e8 01 4c 39 f0 0f 86 a8 07 00 00 e8 53 dd ca ff 49 8d 46 01 48 89 85 58 ff ff ff 48 8b 85 60 ff ff ff <42> 0f b6 0c 30 89 c8 88 8d 75 ff ff ff 83 e0 1f 89 8d 28 ff ff
    RIP: asn1_ber_decoder+0x17f/0xe60 lib/asn1_decoder.c:233 RSP: ffff9b6b37973c78
    CR2: 0000000000000000

Fixes: 42d5ec27f8 ("X.509: Add an ASN.1 decoder")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-15 15:53:18 +01:00
Eric Biggers cb14a0dd1f KEYS: fix out-of-bounds read during ASN.1 parsing
commit 2eb9eabf1e upstream.

syzkaller with KASAN reported an out-of-bounds read in
asn1_ber_decoder().  It can be reproduced by the following command,
assuming CONFIG_X509_CERTIFICATE_PARSER=y and CONFIG_KASAN=y:

    keyctl add asymmetric desc $'\x30\x30' @s

The bug is that the length of an ASN.1 data value isn't validated in the
case where it is encoded using the short form, causing the decoder to
read past the end of the input buffer.  Fix it by validating the length.

The bug report was:

    BUG: KASAN: slab-out-of-bounds in asn1_ber_decoder+0x10cb/0x1730 lib/asn1_decoder.c:233
    Read of size 1 at addr ffff88003cccfa02 by task syz-executor0/6818

    CPU: 1 PID: 6818 Comm: syz-executor0 Not tainted 4.14.0-rc7-00008-g5f479447d983 #2
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
    Call Trace:
     __dump_stack lib/dump_stack.c:16 [inline]
     dump_stack+0xb3/0x10b lib/dump_stack.c:52
     print_address_description+0x79/0x2a0 mm/kasan/report.c:252
     kasan_report_error mm/kasan/report.c:351 [inline]
     kasan_report+0x236/0x340 mm/kasan/report.c:409
     __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:427
     asn1_ber_decoder+0x10cb/0x1730 lib/asn1_decoder.c:233
     x509_cert_parse+0x1db/0x650 crypto/asymmetric_keys/x509_cert_parser.c:89
     x509_key_preparse+0x64/0x7a0 crypto/asymmetric_keys/x509_public_key.c:174
     asymmetric_key_preparse+0xcb/0x1a0 crypto/asymmetric_keys/asymmetric_type.c:388
     key_create_or_update+0x347/0xb20 security/keys/key.c:855
     SYSC_add_key security/keys/keyctl.c:122 [inline]
     SyS_add_key+0x1cd/0x340 security/keys/keyctl.c:62
     entry_SYSCALL_64_fastpath+0x1f/0xbe
    RIP: 0033:0x447c89
    RSP: 002b:00007fca7a5d3bd8 EFLAGS: 00000246 ORIG_RAX: 00000000000000f8
    RAX: ffffffffffffffda RBX: 00007fca7a5d46cc RCX: 0000000000447c89
    RDX: 0000000020006f4a RSI: 0000000020006000 RDI: 0000000020001ff5
    RBP: 0000000000000046 R08: fffffffffffffffd R09: 0000000000000000
    R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
    R13: 0000000000000000 R14: 00007fca7a5d49c0 R15: 00007fca7a5d4700

Fixes: 42d5ec27f8 ("X.509: Add an ASN.1 decoder")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-08 10:08:31 +01:00
David Howells 67bcc5e530 assoc_array: Fix a buggy node-splitting case
commit ea6789980f upstream.

This fixes CVE-2017-12193.

Fix a case in the assoc_array implementation in which a new leaf is
added that needs to go into a node that happens to be full, where the
existing leaves in that node cluster together at that level to the
exclusion of new leaf.

What needs to happen is that the existing leaves get moved out to a new
node, N1, at level + 1 and the existing node needs replacing with one,
N0, that has pointers to the new leaf and to N1.

The code that tries to do this gets this wrong in two ways:

 (1) The pointer that should've pointed from N0 to N1 is set to point
     recursively to N0 instead.

 (2) The backpointer from N0 needs to be set correctly in the case N0 is
     either the root node or reached through a shortcut.

Fix this by removing this path and using the split_node path instead,
which achieves the same end, but in a more general way (thanks to Eric
Biggers for spotting the redundancy).

The problem manifests itself as:

  BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
  IP: assoc_array_apply_edit+0x59/0xe5

Fixes: 3cb989501c ("Add a generic associative array implementation.")
Reported-and-tested-by: WU Fan <u3536072@connect.hku.hk>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 09:49:14 +01:00
Eric Biggers f9e7e2d605 lib/digsig: fix dereference of NULL user_key_payload
commit 192cabd6a2 upstream.

digsig_verify() requests a user key, then accesses its payload.
However, a revoked key has a NULL payload, and we failed to check for
this.  request_key() *does* skip revoked keys, but there is still a
window where the key can be revoked before we acquire its semaphore.

Fix it by checking for a NULL payload, treating it like a key which was
already revoked at the time it was requested.

Fixes: 051dbb918c ("crypto: digital signature verification support")
Reviewed-by: James Morris <james.l.morris@oracle.com>
Cc: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-27 10:38:08 +02:00
Sergey Senozhatsky 1c0891295a lib/ratelimit.c: use deferred printk() version
commit 656d61ce96 upstream.

printk_ratelimit() invokes ___ratelimit() which may invoke a normal
printk() (pr_warn() in this particular case) to warn about suppressed
output.  Given that printk_ratelimit() may be called from anywhere, that
pr_warn() is dangerous - it may end up deadlocking the system.  Fix
___ratelimit() by using deferred printk().

Sasha reported the following lockdep error:

 : Unregister pv shared memory for cpu 8
 : select_fallback_rq: 3 callbacks suppressed
 : process 8583 (trinity-c78) no longer affine to cpu8
 :
 : ======================================================
 : WARNING: possible circular locking dependency detected
 : 4.14.0-rc2-next-20170927+ #252 Not tainted
 : ------------------------------------------------------
 : migration/8/62 is trying to acquire lock:
 : (&port_lock_key){-.-.}, at: serial8250_console_write()
 :
 : but task is already holding lock:
 : (&rq->lock){-.-.}, at: sched_cpu_dying()
 :
 : which lock already depends on the new lock.
 :
 :
 : the existing dependency chain (in reverse order) is:
 :
 : -> #3 (&rq->lock){-.-.}:
 : __lock_acquire()
 : lock_acquire()
 : _raw_spin_lock()
 : task_fork_fair()
 : sched_fork()
 : copy_process.part.31()
 : _do_fork()
 : kernel_thread()
 : rest_init()
 : start_kernel()
 : x86_64_start_reservations()
 : x86_64_start_kernel()
 : verify_cpu()
 :
 : -> #2 (&p->pi_lock){-.-.}:
 : __lock_acquire()
 : lock_acquire()
 : _raw_spin_lock_irqsave()
 : try_to_wake_up()
 : default_wake_function()
 : woken_wake_function()
 : __wake_up_common()
 : __wake_up_common_lock()
 : __wake_up()
 : tty_wakeup()
 : tty_port_default_wakeup()
 : tty_port_tty_wakeup()
 : uart_write_wakeup()
 : serial8250_tx_chars()
 : serial8250_handle_irq.part.25()
 : serial8250_default_handle_irq()
 : serial8250_interrupt()
 : __handle_irq_event_percpu()
 : handle_irq_event_percpu()
 : handle_irq_event()
 : handle_level_irq()
 : handle_irq()
 : do_IRQ()
 : ret_from_intr()
 : native_safe_halt()
 : default_idle()
 : arch_cpu_idle()
 : default_idle_call()
 : do_idle()
 : cpu_startup_entry()
 : rest_init()
 : start_kernel()
 : x86_64_start_reservations()
 : x86_64_start_kernel()
 : verify_cpu()
 :
 : -> #1 (&tty->write_wait){-.-.}:
 : __lock_acquire()
 : lock_acquire()
 : _raw_spin_lock_irqsave()
 : __wake_up_common_lock()
 : __wake_up()
 : tty_wakeup()
 : tty_port_default_wakeup()
 : tty_port_tty_wakeup()
 : uart_write_wakeup()
 : serial8250_tx_chars()
 : serial8250_handle_irq.part.25()
 : serial8250_default_handle_irq()
 : serial8250_interrupt()
 : __handle_irq_event_percpu()
 : handle_irq_event_percpu()
 : handle_irq_event()
 : handle_level_irq()
 : handle_irq()
 : do_IRQ()
 : ret_from_intr()
 : native_safe_halt()
 : default_idle()
 : arch_cpu_idle()
 : default_idle_call()
 : do_idle()
 : cpu_startup_entry()
 : rest_init()
 : start_kernel()
 : x86_64_start_reservations()
 : x86_64_start_kernel()
 : verify_cpu()
 :
 : -> #0 (&port_lock_key){-.-.}:
 : check_prev_add()
 : __lock_acquire()
 : lock_acquire()
 : _raw_spin_lock_irqsave()
 : serial8250_console_write()
 : univ8250_console_write()
 : console_unlock()
 : vprintk_emit()
 : vprintk_default()
 : vprintk_func()
 : printk()
 : ___ratelimit()
 : __printk_ratelimit()
 : select_fallback_rq()
 : sched_cpu_dying()
 : cpuhp_invoke_callback()
 : take_cpu_down()
 : multi_cpu_stop()
 : cpu_stopper_thread()
 : smpboot_thread_fn()
 : kthread()
 : ret_from_fork()
 :
 : other info that might help us debug this:
 :
 : Chain exists of:
 :   &port_lock_key --> &p->pi_lock --> &rq->lock
 :
 :  Possible unsafe locking scenario:
 :
 :        CPU0                    CPU1
 :        ----                    ----
 :   lock(&rq->lock);
 :                                lock(&p->pi_lock);
 :                                lock(&rq->lock);
 :   lock(&port_lock_key);
 :
 :  *** DEADLOCK ***
 :
 : 4 locks held by migration/8/62:
 : #0: (&p->pi_lock){-.-.}, at: sched_cpu_dying()
 : #1: (&rq->lock){-.-.}, at: sched_cpu_dying()
 : #2: (printk_ratelimit_state.lock){....}, at: ___ratelimit()
 : #3: (console_lock){+.+.}, at: vprintk_emit()
 :
 : stack backtrace:
 : CPU: 8 PID: 62 Comm: migration/8 Not tainted 4.14.0-rc2-next-20170927+ #252
 : Call Trace:
 : dump_stack()
 : print_circular_bug()
 : check_prev_add()
 : ? add_lock_to_list.isra.26()
 : ? check_usage()
 : ? kvm_clock_read()
 : ? kvm_sched_clock_read()
 : ? sched_clock()
 : ? check_preemption_disabled()
 : __lock_acquire()
 : ? __lock_acquire()
 : ? add_lock_to_list.isra.26()
 : ? debug_check_no_locks_freed()
 : ? memcpy()
 : lock_acquire()
 : ? serial8250_console_write()
 : _raw_spin_lock_irqsave()
 : ? serial8250_console_write()
 : serial8250_console_write()
 : ? serial8250_start_tx()
 : ? lock_acquire()
 : ? memcpy()
 : univ8250_console_write()
 : console_unlock()
 : ? __down_trylock_console_sem()
 : vprintk_emit()
 : vprintk_default()
 : vprintk_func()
 : printk()
 : ? show_regs_print_info()
 : ? lock_acquire()
 : ___ratelimit()
 : __printk_ratelimit()
 : select_fallback_rq()
 : sched_cpu_dying()
 : ? sched_cpu_starting()
 : ? rcutree_dying_cpu()
 : ? sched_cpu_starting()
 : cpuhp_invoke_callback()
 : ? cpu_disable_common()
 : take_cpu_down()
 : ? trace_hardirqs_off_caller()
 : ? cpuhp_invoke_callback()
 : multi_cpu_stop()
 : ? __this_cpu_preempt_check()
 : ? cpu_stop_queue_work()
 : cpu_stopper_thread()
 : ? cpu_stop_create()
 : smpboot_thread_fn()
 : ? sort_range()
 : ? schedule()
 : ? __kthread_parkme()
 : kthread()
 : ? sort_range()
 : ? kthread_create_on_node()
 : ret_from_fork()
 : process 9121 (trinity-c78) no longer affine to cpu8
 : smpboot: CPU 8 is now offline

Link: http://lkml.kernel.org/r/20170928120405.18273-1-sergey.senozhatsky@gmail.com
Fixes: 6b1d174b0c ("ratelimit: extend to print suppressed messages on release")
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Reported-by: Sasha Levin <levinsasha928@gmail.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Borislav Petkov <bp@suse.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-12 11:51:19 +02:00
Stephan Mueller 31decdcd83 lib/mpi: kunmap after finishing accessing buffer
commit dea3eb8b45 upstream.

Using sg_miter_start and sg_miter_next, the buffer of an SG is kmap'ed
to *buff. The current code calls sg_miter_stop (and thus kunmap) on the
SG entry before the last access of *buff.

The patch moves the sg_miter_stop call after the last access to *buff to
ensure that the memory pointed to by *buff is still mapped.

Fixes: 4816c94064 ("lib/mpi: Fix SG miter leak")
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-07 08:35:40 +02:00
Greg Kroah-Hartman 529ada21ff lz4: fix bogus gcc warning
When building lz4 under gcc-7 we get the following bogus warning:

  CC [M]  lib/lz4/lz4hc_compress.o
lib/lz4/lz4hc_compress.c: In function ‘lz4hc_compress’:
lib/lz4/lz4hc_compress.c:179:42: warning: ‘delta’ may be used uninitialized in this function [-Wmaybe-uninitialized]
    chaintable[(size_t)(ptr) & MAXD_MASK] = delta;
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~
lib/lz4/lz4hc_compress.c:134:6: note: ‘delta’ was declared here
  u16 delta;
      ^~~~~

This doesn't show up in the 4.4-stable tree due to us turning off
warnings like this.  It also doesn't show up in newer kernel versions as
this code was totally rewritten.

So for now, to get the 4.9-stable tree to build with 0 warnings on x86
allmodconfig, let's just shut the compiler up by initializing the
variable to 0, despite it not really doing anything.

To be far, this code is crazy complex, so the fact that gcc can't
determine if the variable is really used or not isn't that bad, I'd
blame the code here instead of the compiler.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-09-02 07:07:54 +02:00
Sudip Mukherjee d12824c897 lib/Kconfig.debug: fix frv build failure
[ Upstream commit da0510c475 ]

The build of frv allmodconfig was failing with the errors like:

  /tmp/cc0JSPc3.s: Assembler messages:
  /tmp/cc0JSPc3.s:1839: Error: symbol `.LSLT0' is already defined
  /tmp/cc0JSPc3.s:1842: Error: symbol `.LASLTP0' is already defined
  /tmp/cc0JSPc3.s:1969: Error: symbol `.LELTP0' is already defined
  /tmp/cc0JSPc3.s:1970: Error: symbol `.LELT0' is already defined

Commit 866ced950b ("kbuild: Support split debug info v4") introduced
splitting the debug info and keeping that in a separate file.  Somehow,
the frv-linux gcc did not like that and I am guessing that instead of
splitting it started copying.  The first report about this is at:

  https://lists.01.org/pipermail/kbuild-all/2015-July/010527.html.

I will try and see if this can work with frv and if still fails I will
open a bug report with gcc.  But meanwhile this is the easiest option to
solve build failure of frv.

Fixes: 866ced950b ("kbuild: Support split debug info v4")
Link: http://lkml.kernel.org/r/1482062348-5352-1-git-send-email-sudipm.mukherjee@gmail.com
Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-11 08:49:36 -07:00
Peter Zijlstra 542ebc96c2 sched/fair, cpumask: Export for_each_cpu_wrap()
commit c6508a39640b9a27fc2bc10cb708152672c82045 upstream.

commit c743f0a5c5 upstream.

More users for for_each_cpu_wrap() have appeared. Promote the construct
to generic cpumask interface.

The implementation is slightly modified to reduce arguments.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Lauro Ramos Venancio <lvenanci@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: lwang@redhat.com
Link: http://lkml.kernel.org/r/20170414122005.o35me2h5nowqkxbv@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-21 07:42:23 +02:00
Nikita Yushchenko 9d00195bc0 swiotlb: ensure that page-sized mappings are page-aligned
[ Upstream commit 602d9858f0 ]

Some drivers do depend on page mappings to be page aligned.

Swiotlb already enforces such alignment for mappings greater than page,
extend that to page-sized mappings as well.

Without this fix, nvme hits BUG() in nvme_setup_prps(), because that routine
assumes page-aligned mappings.

Signed-off-by: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Konrad Rzeszutek Wilk <konrad@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-05 14:40:26 +02:00
Ilya Matveychikov 7c679fe729 lib/cmdline.c: fix get_options() overflow while parsing ranges
commit a91e0f680b upstream.

When using get_options() it's possible to specify a range of numbers,
like 1-100500.  The problem is that it doesn't track array size while
calling internally to get_range() which iterates over the range and
fills the memory with numbers.

Link: http://lkml.kernel.org/r/2613C75C-B04D-4BFF-82A6-12F97BA0F620@gmail.com
Signed-off-by: Ilya V. Matveychikov <matvejchikov@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-29 13:00:28 +02:00
David Miller b355b899c7 crypto: Work around deallocated stack frame reference gcc bug on sparc.
commit d41519a69b upstream.

On sparc, if we have an alloca() like situation, as is the case with
SHASH_DESC_ON_STACK(), we can end up referencing deallocated stack
memory.  The result can be that the value is clobbered if a trap
or interrupt arrives at just the right instruction.

It only occurs if the function ends returning a value from that
alloca() area and that value can be placed into the return value
register using a single instruction.

For example, in lib/libcrc32c.c:crc32c() we end up with a return
sequence like:

        return  %i7+8
         lduw   [%o5+16], %o0   ! MEM[(u32 *)__shash_desc.1_10 + 16B],

%o5 holds the base of the on-stack area allocated for the shash
descriptor.  But the return released the stack frame and the
register window.

So if an intererupt arrives between 'return' and 'lduw', then
the value read at %o5+16 can be corrupted.

Add a data compiler barrier to work around this problem.  This is
exactly what the gcc fix will end up doing as well, and it absolutely
should not change the code generated for other cpus (unless gcc
on them has the same bug :-)

With crucial insight from Eric Sandeen.

Reported-by: Anatoly Pugachev <matorola@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-24 07:11:17 +02:00
Kees Cook a6a7d8ade8 usercopy: Adjust tests to deal with SMAP/PAN
commit f5f893c57e upstream.

Under SMAP/PAN/etc, we cannot write directly to userspace memory, so
this rearranges the test bytes to get written through copy_to_user().
Additionally drops the bad copy_from_user() test that would trigger a
memcpy() against userspace on failure.

[arnd: the test module was added in 3.14, and this backported patch
       should apply cleanly on all version from 3.14 to 4.10.
       The original patch was in 4.11 on top of a context change
       I saw the bug triggered with kselftest on a 4.4.y stable kernel]

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-14 15:06:05 +02:00
Daniel Borkmann 493d0a7be3 bpf, arm64: fix jit branch offset related to ldimm64
[ Upstream commit ddc665a4bb ]

When the instruction right before the branch destination is
a 64 bit load immediate, we currently calculate the wrong
jump offset in the ctx->offset[] array as we only account
one instruction slot for the 64 bit load immediate although
it uses two BPF instructions. Fix it up by setting the offset
into the right slot after we incremented the index.

Before (ldimm64 test 1):

  [...]
  00000020:  52800007  mov w7, #0x0 // #0
  00000024:  d2800060  mov x0, #0x3 // #3
  00000028:  d2800041  mov x1, #0x2 // #2
  0000002c:  eb01001f  cmp x0, x1
  00000030:  54ffff82  b.cs 0x00000020
  00000034:  d29fffe7  mov x7, #0xffff // #65535
  00000038:  f2bfffe7  movk x7, #0xffff, lsl #16
  0000003c:  f2dfffe7  movk x7, #0xffff, lsl #32
  00000040:  f2ffffe7  movk x7, #0xffff, lsl #48
  00000044:  d29dddc7  mov x7, #0xeeee // #61166
  00000048:  f2bdddc7  movk x7, #0xeeee, lsl #16
  0000004c:  f2ddddc7  movk x7, #0xeeee, lsl #32
  00000050:  f2fdddc7  movk x7, #0xeeee, lsl #48
  [...]

After (ldimm64 test 1):

  [...]
  00000020:  52800007  mov w7, #0x0 // #0
  00000024:  d2800060  mov x0, #0x3 // #3
  00000028:  d2800041  mov x1, #0x2 // #2
  0000002c:  eb01001f  cmp x0, x1
  00000030:  540000a2  b.cs 0x00000044
  00000034:  d29fffe7  mov x7, #0xffff // #65535
  00000038:  f2bfffe7  movk x7, #0xffff, lsl #16
  0000003c:  f2dfffe7  movk x7, #0xffff, lsl #32
  00000040:  f2ffffe7  movk x7, #0xffff, lsl #48
  00000044:  d29dddc7  mov x7, #0xeeee // #61166
  00000048:  f2bdddc7  movk x7, #0xeeee, lsl #16
  0000004c:  f2ddddc7  movk x7, #0xeeee, lsl #32
  00000050:  f2fdddc7  movk x7, #0xeeee, lsl #48
  [...]

Also, add a couple of test cases to make sure JITs pass
this test. Tested on Cavium ThunderX ARMv8. The added
test cases all pass after the fix.

Fixes: 8eee539dde ("arm64: bpf: fix out-of-bounds read in bpf2a64_offset()")
Reported-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Xi Wang <xi.wang@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-14 14:00:21 +02:00
Al Viro ff76ab9e03 new privimitive: iov_iter_revert()
commit 27c0e3748e upstream.

opposite to iov_iter_advance(); the caller is responsible for never
using it to move back past the initial position.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-21 09:31:21 +02:00
Kees Cook 673dfb6d1b lib/syscall: Clear return values when no stack
commit 854fbd6e5f upstream.

Commit:

  aa1f1a6396 ("lib/syscall: Pin the task stack in collect_syscall()")

... added logic to handle a process stack not existing, but left sp and pc
uninitialized, which can be later reported via /proc/$pid/syscall for zombie
processes, potentially exposing kernel memory to userspace.

  Zombie /proc/$pid/syscall before:
  -1 0xffffffff9a060100 0xffff92f42d6ad900

  Zombie /proc/$pid/syscall after:
  -1 0x0 0x0

Reported-by: Robert Święcki <robert@swiecki.net>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: aa1f1a6396 ("lib/syscall: Pin the task stack in collect_syscall()")
Link: http://lkml.kernel.org/r/20170323224616.GA92694@beast
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-04-08 09:30:35 +02:00
Geert Uytterhoeven 41c6b3e898 swiotlb: Add swiotlb=noforce debug option
commit fff5d99225 upstream.

On architectures like arm64, swiotlb is tied intimately to the core
architecture DMA support. In addition, ZONE_DMA cannot be disabled.

To aid debugging and catch devices not supporting DMA to memory outside
the 32-bit address space, add a kernel command line option
"swiotlb=noforce", which disables the use of bounce buffers.
If specified, trying to map memory that cannot be used with DMA will
fail, and a rate-limited warning will be printed.

Note that io_tlb_nslabs is set to 1, which is the minimal supported
value.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-26 08:24:44 +01:00
Geert Uytterhoeven 1fd1e6cd63 swiotlb: Convert swiotlb_force from int to enum
commit ae7871be18 upstream.

Convert the flag swiotlb_force from an int to an enum, to prepare for
the advent of more possible values.

Suggested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-26 08:24:44 +01:00
Al Viro d06367ac17 fix a fencepost error in pipe_advance()
commit b9dc6f65bc upstream.

The logics in pipe_advance() used to release all buffers past the new
position failed in cases when the number of buffers to release was equal
to pipe->buffers.  If that happened, none of them had been released,
leaving pipe full.  Worse, it was trivial to trigger and we end up with
pipe full of uninitialized pages.  IOW, it's an infoleak.

Reported-by: "Alan J. Wylie" <alan@wylie.me.uk>
Tested-by: "Alan J. Wylie" <alan@wylie.me.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-19 20:18:02 +01:00
Linus Torvalds 2b41226b39 Revert "radix tree test suite: fix compilation"
This reverts commit 53855d10f4.

It shouldn't have come in yet - it depends on the changes in linux-next
that will come in during the next merge window.  As Matthew Wilcox says,
the test suite is broken with the current state without the revert.

Requested-by: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-09 10:41:42 -08:00
Matthew Wilcox 53855d10f4 radix tree test suite: fix compilation
Patch "lib/radix-tree: Convert to hotplug state machine" breaks the test
suite as it adds a call to cpuhp_setup_state_nocalls() which is not
currently emulated in the test suite.  Add it, and delete the emulation
of the old CPU hotplug mechanism.

Link: http://lkml.kernel.org/r/1480369871-5271-36-git-send-email-mawilcox@linuxonhyperv.com
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-07 17:10:00 -08:00
Linus Torvalds 5b43f97f3f Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Ingo Molnar:
 "Two rtmutex race fixes (which miraculously never triggered, that we
  know of), plus two lockdep printk formatting regression fixes"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lockdep: Fix report formatting
  locking/rtmutex: Use READ_ONCE() in rt_mutex_owner()
  locking/rtmutex: Prevent dequeue vs. unlock race
  locking/selftest: Fix output since KERN_CONT changes
2016-12-07 11:27:33 -08:00
Dmitry Vyukov 828347f8f9 kasan: support use-after-scope detection
Gcc revision 241896 implements use-after-scope detection.  Will be
available in gcc 7.  Support it in KASAN.

Gcc emits 2 new callbacks to poison/unpoison large stack objects when
they go in/out of scope.  Implement the callbacks and add a test.

[dvyukov@google.com: v3]
  Link: http://lkml.kernel.org/r/1479998292-144502-1-git-send-email-dvyukov@google.com
Link: http://lkml.kernel.org/r/1479226045-145148-1-git-send-email-dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: <stable@vger.kernel.org>	[4.0+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-11-30 16:32:52 -08:00
Chris Wilson f8ff04e2be lib/debugobjects: export for use in modules
Drivers, or other modules, that use a mixture of objects (especially
objects embedded within other objects) would like to take advantage of
the debugobjects facilities to help catch misuse.  Currently, the
debugobjects interface is only available to builtin drivers and requires
a set of EXPORT_SYMBOL_GPL for use by modules.

I am using the debugobjects in i915.ko to try and catch some invalid
operations on embedded objects.  The problem currently only presents
itself across module unload so forcing i915 to be builtin is not an
option.

Link: http://lkml.kernel.org/r/20161122143039.6433-1-chris@chris-wilson.co.uk
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: "Du, Changbin" <changbin.du@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-11-30 16:32:52 -08:00
Michael Ellerman 2513940989 locking/selftest: Fix output since KERN_CONT changes
Since the KERN_CONT changes the locking-selftest output is messed up, eg:

  ----------------------------------------------------------------------------
                                   | spin |wlock |rlock |mutex | wsem | rsem |
    --------------------------------------------------------------------------
                       A-A deadlock:
    ok  |
    ok  |
    ok  |
    ok  |
    ok  |
    ok  |

Use pr_cont() to get it looking normal again:

  ----------------------------------------------------------------------------
                                   | spin |wlock |rlock |mutex | wsem | rsem |
    --------------------------------------------------------------------------
                       A-A deadlock:  ok  |  ok  |  ok  |  ok  |  ok  |  ok  |

Reported-by: Christian Kujau <lists@nerdbynature.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linuxppc-dev@ozlabs.org
Link: http://lkml.kernel.org/r/1480027528-934-1-git-send-email-mpe@ellerman.id.au
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-11-25 07:12:19 +01:00
Andrey Ryabinin f5527fffff mpi: Fix NULL ptr dereference in mpi_powm() [ver #3]
This fixes CVE-2016-8650.

If mpi_powm() is given a zero exponent, it wants to immediately return
either 1 or 0, depending on the modulus.  However, if the result was
initalised with zero limb space, no limbs space is allocated and a
NULL-pointer exception ensues.

Fix this by allocating a minimal amount of limb space for the result when
the 0-exponent case when the result is 1 and not touching the limb space
when the result is 0.

This affects the use of RSA keys and X.509 certificates that carry them.

BUG: unable to handle kernel NULL pointer dereference at           (null)
IP: [<ffffffff8138ce5d>] mpi_powm+0x32/0x7e6
PGD 0
Oops: 0002 [#1] SMP
Modules linked in:
CPU: 3 PID: 3014 Comm: keyctl Not tainted 4.9.0-rc6-fscache+ #278
Hardware name: ASUS All Series/H97-PLUS, BIOS 2306 10/09/2014
task: ffff8804011944c0 task.stack: ffff880401294000
RIP: 0010:[<ffffffff8138ce5d>]  [<ffffffff8138ce5d>] mpi_powm+0x32/0x7e6
RSP: 0018:ffff880401297ad8  EFLAGS: 00010212
RAX: 0000000000000000 RBX: ffff88040868bec0 RCX: ffff88040868bba0
RDX: ffff88040868b260 RSI: ffff88040868bec0 RDI: ffff88040868bee0
RBP: ffff880401297ba8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000047 R11: ffffffff8183b210 R12: 0000000000000000
R13: ffff8804087c7600 R14: 000000000000001f R15: ffff880401297c50
FS:  00007f7a7918c700(0000) GS:ffff88041fb80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000401250000 CR4: 00000000001406e0
Stack:
 ffff88040868bec0 0000000000000020 ffff880401297b00 ffffffff81376cd4
 0000000000000100 ffff880401297b10 ffffffff81376d12 ffff880401297b30
 ffffffff81376f37 0000000000000100 0000000000000000 ffff880401297ba8
Call Trace:
 [<ffffffff81376cd4>] ? __sg_page_iter_next+0x43/0x66
 [<ffffffff81376d12>] ? sg_miter_get_next_page+0x1b/0x5d
 [<ffffffff81376f37>] ? sg_miter_next+0x17/0xbd
 [<ffffffff8138ba3a>] ? mpi_read_raw_from_sgl+0xf2/0x146
 [<ffffffff8132a95c>] rsa_verify+0x9d/0xee
 [<ffffffff8132acca>] ? pkcs1pad_sg_set_buf+0x2e/0xbb
 [<ffffffff8132af40>] pkcs1pad_verify+0xc0/0xe1
 [<ffffffff8133cb5e>] public_key_verify_signature+0x1b0/0x228
 [<ffffffff8133d974>] x509_check_for_self_signed+0xa1/0xc4
 [<ffffffff8133cdde>] x509_cert_parse+0x167/0x1a1
 [<ffffffff8133d609>] x509_key_preparse+0x21/0x1a1
 [<ffffffff8133c3d7>] asymmetric_key_preparse+0x34/0x61
 [<ffffffff812fc9f3>] key_create_or_update+0x145/0x399
 [<ffffffff812fe227>] SyS_add_key+0x154/0x19e
 [<ffffffff81001c2b>] do_syscall_64+0x80/0x191
 [<ffffffff816825e4>] entry_SYSCALL64_slow_path+0x25/0x25
Code: 56 41 55 41 54 53 48 81 ec a8 00 00 00 44 8b 71 04 8b 42 04 4c 8b 67 18 45 85 f6 89 45 80 0f 84 b4 06 00 00 85 c0 75 2f 41 ff ce <49> c7 04 24 01 00 00 00 b0 01 75 0b 48 8b 41 18 48 83 38 01 0f
RIP  [<ffffffff8138ce5d>] mpi_powm+0x32/0x7e6
 RSP <ffff880401297ad8>
CR2: 0000000000000000
---[ end trace d82015255d4a5d8d ]---

Basically, this is a backport of a libgcrypt patch:

	http://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git;a=patch;h=6e1adb05d290aeeb1c230c763970695f4a538526

Fixes: cdec9cb516 ("crypto: GnuPG based MPI lib - source files (part 1)")
Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
cc: linux-ima-devel@lists.sourceforge.net
cc: stable@vger.kernel.org
Signed-off-by: James Morris <james.l.morris@oracle.com>
2016-11-25 12:57:50 +11:00
Linus Torvalds 8d1a2408ef Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc
Pull sparc fixes from David Miller:

 1) With modern networking cards we can run out of 32-bit DMA space, so
    support 64-bit DMA addressing when possible on sparc64. From Dave
    Tushar.

 2) Some signal frame validation checks are inverted on sparc32, fix
    from Andreas Larsson.

 3) Lockdep tables can get too large in some circumstances on sparc64,
    add a way to adjust the size a bit. From Babu Moger.

 4) Fix NUMA node probing on some sun4v systems, from Thomas Tai.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc: drop duplicate header scatterlist.h
  lockdep: Limit static allocations if PROVE_LOCKING_SMALL is defined
  config: Adding the new config parameter CONFIG_PROVE_LOCKING_SMALL for sparc
  sunbmac: Fix compiler warning
  sunqe: Fix compiler warnings
  sparc64: Enable 64-bit DMA
  sparc64: Enable sun4v dma ops to use IOMMU v2 APIs
  sparc64: Bind PCIe devices to use IOMMU v2 service
  sparc64: Initialize iommu_map_table and iommu_pool
  sparc64: Add ATU (new IOMMU) support
  sparc64: Add FORCE_MAX_ZONEORDER and default to 13
  sparc64: fix compile warning section mismatch in find_node()
  sparc32: Fix inverted invalid_frame_pointer checks on sigreturns
  sparc64: Fix find_node warning if numa node cannot be found
2016-11-21 13:56:17 -08:00
Babu Moger e6b5f1be7a config: Adding the new config parameter CONFIG_PROVE_LOCKING_SMALL for sparc
This new config parameter limits the space used for "Lock debugging:
prove locking correctness" by about 4MB. The current sparc systems have
the limitation of 32MB size for kernel size including .text, .data and
.bss sections. With PROVE_LOCKING feature, the kernel size could grow
beyond this limit and causing system boot-up issues. With this option,
kernel limits the size of the entries of lock_chains, stack_trace etc.,
so that kernel fits in required size limit. This is not visible to user
and only used for sparc.

Signed-off-by: Babu Moger <babu.moger@oracle.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-18 11:33:19 -08:00
Abhi Das 680bb946a1 fix iov_iter_advance() for ITER_PIPE
iov_iter_advance() needs to decrement iter->count by the number of
bytes we'd moved beyond.  Normal flavours do that, but ITER_PIPE
doesn't and ITER_PIPE generic_file_read_iter() for O_DIRECT files
ends up with a bogus fallback to page cache read, resulting in incorrect
values for file offset and bytes read.

Signed-off-by: Abhi Das <adas@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-11-17 00:00:48 -05:00
Chris Wilson ae65a21fb8 lib/stackdepot: export save/fetch stack for drivers
Some drivers would like to record stacktraces in order to aide leak
tracing.  As stackdepot already provides a facility for only storing the
unique traces, thereby reducing the memory required, export that
functionality for use by drivers.

The code was originally created for KASAN and moved under lib in commit
cd11016e5f ("mm, kasan: stackdepot implementation.  Enable stackdepot
for SLAB") so that it could be shared with mm/.  In turn, we want to
share it now with drivers.

Link: http://lkml.kernel.org/r/20161108133209.22704-1-chris@chris-wilson.co.uk
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-11-11 08:12:37 -08:00
Linus Torvalds 2a26d99b25 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:
 "Lots of fixes, mostly drivers as is usually the case.

   1) Don't treat zero DMA address as invalid in vmxnet3, from Alexey
      Khoroshilov.

   2) Fix element timeouts in netfilter's nft_dynset, from Anders K.
      Pedersen.

   3) Don't put aead_req crypto struct on the stack in mac80211, from
      Ard Biesheuvel.

   4) Several uninitialized variable warning fixes from Arnd Bergmann.

   5) Fix memory leak in cxgb4, from Colin Ian King.

   6) Fix bpf handling of VLAN header push/pop, from Daniel Borkmann.

   7) Several VRF semantic fixes from David Ahern.

   8) Set skb->protocol properly in ip6_tnl_xmit(), from Eli Cooper.

   9) Socket needs to be locked in udp_disconnect(), from Eric Dumazet.

  10) Div-by-zero on 32-bit fix in mlx4 driver, from Eugenia Emantayev.

  11) Fix stale link state during failover in NCSCI driver, from Gavin
      Shan.

  12) Fix netdev lower adjacency list traversal, from Ido Schimmel.

  13) Propvide proper handle when emitting notifications of filter
      deletes, from Jamal Hadi Salim.

  14) Memory leaks and big-endian issues in rtl8xxxu, from Jes Sorensen.

  15) Fix DESYNC_FACTOR handling in ipv6, from Jiri Bohac.

  16) Several routing offload fixes in mlxsw driver, from Jiri Pirko.

  17) Fix broadcast sync problem in TIPC, from Jon Paul Maloy.

  18) Validate chunk len before using it in SCTP, from Marcelo Ricardo
      Leitner.

  19) Revert a netns locking change that causes regressions, from Paul
      Moore.

  20) Add recursion limit to GRO handling, from Sabrina Dubroca.

  21) GFP_KERNEL in irq context fix in ibmvnic, from Thomas Falcon.

  22) Avoid accessing stale vxlan/geneve socket in data path, from
      Pravin Shelar"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (189 commits)
  geneve: avoid using stale geneve socket.
  vxlan: avoid using stale vxlan socket.
  qede: Fix out-of-bound fastpath memory access
  net: phy: dp83848: add dp83822 PHY support
  enic: fix rq disable
  tipc: fix broadcast link synchronization problem
  ibmvnic: Fix missing brackets in init_sub_crq_irqs
  ibmvnic: Fix releasing of sub-CRQ IRQs in interrupt context
  Revert "ibmvnic: Fix releasing of sub-CRQ IRQs in interrupt context"
  arch/powerpc: Update parameters for csum_tcpudp_magic & csum_tcpudp_nofold
  net/mlx4_en: Save slave ethtool stats command
  net/mlx4_en: Fix potential deadlock in port statistics flow
  net/mlx4: Fix firmware command timeout during interrupt test
  net/mlx4_core: Do not access comm channel if it has not yet been initialized
  net/mlx4_en: Fix panic during reboot
  net/mlx4_en: Process all completions in RX rings after port goes up
  net/mlx4_en: Resolve dividing by zero in 32-bit system
  net/mlx4_core: Change the default value of enable_qos
  net/mlx4_core: Avoid setting ports to auto when only one port type is supported
  net/mlx4_core: Fix the resource-type enum in res tracker to conform to FW spec
  ...
2016-10-29 20:33:20 -07:00
Daniel Mentz 62e931fac4 lib/genalloc.c: start search from start of chunk
gen_pool_alloc_algo() iterates over the chunks of a pool trying to find
a contiguous block of memory that satisfies the allocation request.

The shortcut

	if (size > atomic_read(&chunk->avail))
		continue;

makes the loop skip over chunks that do not have enough bytes left to
fulfill the request.  There are two situations, though, where an
allocation might still fail:

(1) The available memory is not contiguous, i.e.  the request cannot
    be fulfilled due to external fragmentation.

(2) A race condition.  Another thread runs the same code concurrently
    and is quicker to grab the available memory.

In those situations, the loop calls pool->algo() to search the entire
chunk, and pool->algo() returns some value that is >= end_bit to
indicate that the search failed.  This return value is then assigned to
start_bit.  The variables start_bit and end_bit describe the range that
should be searched, and this range should be reset for every chunk that
is searched.  Today, the code fails to reset start_bit to 0.  As a
result, prefixes of subsequent chunks are ignored.  Memory allocations
might fail even though there is plenty of room left in these prefixes of
those other chunks.

Fixes: 7f184275aa ("lib, Make gen_pool memory allocator lockless")
Link: http://lkml.kernel.org/r/1477420604-28918-1-git-send-email-danielmentz@google.com
Signed-off-by: Daniel Mentz <danielmentz@google.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-27 18:43:43 -07:00
Dmitry Vyukov 02754e0a48 lib/stackdepot.c: bump stackdepot capacity from 16MB to 128MB
KASAN uses stackdepot to memorize stacks for all kmalloc/kfree calls.
Current stackdepot capacity is 16MB (1024 top level entries x 4 pages on
second level).  Size of each stack is (num_frames + 3) * sizeof(long).
Which gives us ~84K stacks.  This capacity was chosen empirically and it
is enough to run kernel normally.

However, when lots of configs are enabled and a fuzzer tries to maximize
code coverage, it easily hits the limit within tens of minutes.  I've
tested for long a time with number of top level entries bumped 4x
(4096).  And I think I've seen overflow only once.  But I don't have all
configs enabled and code coverage has not reached maximum yet.  So bump
it 8x to 8192.

Since we have two-level table, memory cost of this is very moderate --
currently the top-level table is 8KB, with this patch it is 64KB, which
is negligible under KASAN.

Here is some approx math.

128MB allows us to memorize ~670K stacks (assuming stack is ~200b).
I've grepped kernel for kmalloc|kfree|kmem_cache_alloc|kmem_cache_free|
kzalloc|kstrdup|kstrndup|kmemdup and it gives ~60K matches.  Most of
alloc/free call sites are reachable with only one stack.  But some
utility functions can have large fanout.  Assuming average fanout is 5x,
total number of alloc/free stacks is ~300K.

Link: http://lkml.kernel.org/r/1476458416-122131-1-git-send-email-dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Baozeng Ding <sploving1@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-27 18:43:43 -07:00
Kees Cook 0e07f663c9 latent_entropy: raise CONFIG_FRAME_WARN by default
When building with the latent_entropy plugin, set the default
CONFIG_FRAME_WARN to 2048, since some __init functions have many basic
blocks that, when instrumented by the latent_entropy plugin, grow beyond
1024 byte stack size on 32-bit builds.

Link: http://lkml.kernel.org/r/20161018211216.GA39687@beast
Signed-off-by: Kees Cook <keescook@chromium.org>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Cc: Emese Revfy <re.emese@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Michal Marek <mmarek@suse.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-27 18:43:43 -07:00
Daniel Borkmann 0d906b1e8d bpf, test: fix ld_abs + vlan push/pop stress test
After commit 636c262808 ("net: skbuff: Remove errornous length
validation in skb_vlan_pop()") mentioned test case stopped working,
throwing a -12 (ENOMEM) return code. The issue however is not due to
636c262808, but rather due to a buggy test case that got uncovered
from the change in behaviour in 636c262808.

The data_size of that test case for the skb was set to 1. In the
bpf_fill_ld_abs_vlan_push_pop() handler bpf insns are generated that
loop with: reading skb data, pushing 68 tags, reading skb data,
popping 68 tags, reading skb data, etc, in order to force a skb
expansion and thus trigger that JITs recache skb->data. Problem is
that initial data_size is too small.

While before 636c262808, the test silently bailed out due to the
skb->len < VLAN_ETH_HLEN check with returning 0, and now throwing an
error from failing skb_ensure_writable(). Set at least minimum of
ETH_HLEN as an initial length so that on first push of data, equivalent
pop will succeed.

Fixes: 4d9c5c53ac ("test_bpf: add bpf_skb_vlan_push/pop() tests")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-10-20 14:39:06 -04:00
Linus Torvalds 9ffc66941d This adds a new gcc plugin named "latent_entropy". It is designed to
extract as much possible uncertainty from a running system at boot time as
 possible, hoping to capitalize on any possible variation in CPU operation
 (due to runtime data differences, hardware differences, SMP ordering,
 thermal timing variation, cache behavior, etc).
 
 At the very least, this plugin is a much more comprehensive example for
 how to manipulate kernel code using the gcc plugin internals.
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Merge tag 'gcc-plugins-v4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull gcc plugins update from Kees Cook:
 "This adds a new gcc plugin named "latent_entropy". It is designed to
  extract as much possible uncertainty from a running system at boot
  time as possible, hoping to capitalize on any possible variation in
  CPU operation (due to runtime data differences, hardware differences,
  SMP ordering, thermal timing variation, cache behavior, etc).

  At the very least, this plugin is a much more comprehensive example
  for how to manipulate kernel code using the gcc plugin internals"

* tag 'gcc-plugins-v4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  latent_entropy: Mark functions with __latent_entropy
  gcc-plugins: Add latent_entropy plugin
2016-10-15 10:03:15 -07:00
Linus Torvalds b26b5ef5ec Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more misc uaccess and vfs updates from Al Viro:
 "The rest of the stuff from -next (more uaccess work) + assorted fixes"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  score: traps: Add missing include file to fix build error
  fs/super.c: don't fool lockdep in freeze_super() and thaw_super() paths
  fs/super.c: fix race between freeze_super() and thaw_super()
  overlayfs: Fix setting IOP_XATTR flag
  iov_iter: kernel-doc import_iovec() and rw_copy_check_uvector()
  blackfin: no access_ok() for __copy_{to,from}_user()
  arm64: don't zero in __copy_from_user{,_inatomic}
  arm: don't zero in __copy_from_user_inatomic()/__copy_from_user()
  arc: don't leak bits of kernel stack into coredump
  alpha: get rid of tail-zeroing in __copy_user()
2016-10-14 18:19:05 -07:00
Vegard Nossum ffecee4f24 iov_iter: kernel-doc import_iovec() and rw_copy_check_uvector()
Both import_iovec() and rw_copy_check_uvector() take an array
(typically small and on-stack) which is used to hold an iovec array copy
from userspace. This is to avoid an expensive memory allocation in the
fast path (i.e. few iovec elements).

The caller may have to check whether these functions actually used
the provided buffer or allocated a new one -- but this differs between
the too. Let's just add a kernel doc to clarify what the semantics are
for each function.

Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-10-14 20:00:34 -04:00
Linus Torvalds 5d89d9f502 linux-kselftest-4.9-rc1-update
This update consists of:
 
 - Fixes and improvements to existing tests
 - Moving code from Documentation to selftests, samples, and tools.
 
   Moves dnotify_test, prctl, ptp, vDSO, ia64, watchdog, and networking
   tests from Documentation to selftests.
 
   Moves mic/mpssd, misc-devices/mei, timers, watchdog, auxdisplay, and
   blackfin examples from Documentation to samples.
 
   Moves accounting, laptops/dslm, and pcmcia/crc32hash tools from
   Documentation to tools.
 
   Deletes BUILD_DOCSRC and its dependencies.
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Merge tag 'linux-kselftest-4.9-rc1-update' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

Pull kselftest updates from Shuah Khan:
 "This update consists of:

   - Fixes and improvements to existing tests

   - Moving code from Documentation to selftests, samples, and tools:

     * Moves dnotify_test, prctl, ptp, vDSO, ia64, watchdog, and
       networking tests from Documentation to selftests.

     * Moves mic/mpssd, misc-devices/mei, timers, watchdog, auxdisplay,
       and blackfin examples from Documentation to samples.

     * Moves accounting, laptops/dslm, and pcmcia/crc32hash tools from
       Documentation to tools.

     * Deletes BUILD_DOCSRC and its dependencies"

* tag 'linux-kselftest-4.9-rc1-update' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (21 commits)
  selftests/futex: Check ANSI terminal color support
  Doc: update 00-INDEX files to reflect the runnable code move
  samples: move blackfin gptimers-example from Documentation
  tools: move pcmcia crc32hash tool from Documentation
  tools: move laptops dslm tool from Documentation
  tools: move accounting tool from Documentation
  samples: move auxdisplay example code from Documentation
  samples: move watchdog example code from Documentation
  samples: move timers example code from Documentation
  samples: move misc-devices/mei example code from Documentation
  samples: move mic/mpssd example code from Documentation
  selftests: Move networking/timestamping from Documentation
  selftests: move watchdog tests from Documentation/watchdog
  selftests: move ia64 tests from Documentation/ia64
  selftests: move vDSO tests from Documentation/vDSO
  selftests: move ptp tests from Documentation/ptp
  selftests: move prctl tests from Documentation/prctl
  selftests: move dnotify_test from Documentation/filesystems
  selftests/timers: Add missing error code assignment before test
  selftests/zram: replace ZRAM_LZ4_COMPRESS
  ...
2016-10-14 15:17:12 -07:00
Linus Torvalds b6daa51b9a Merge branch 'for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
Pull percpu updates from Tejun Heo:

 - Nick improved generic implementations of percpu operations which
   modify the variable and return so that they calculate the physical
   address only once.

 - percpu_ref percpu <-> atomic mode switching improvements. The
   patchset was originally posted about a year ago but fell through the
   crack.

 - misc non-critical fixes.

* 'for-4.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  mm/percpu.c: fix potential memory leakage for pcpu_embed_first_chunk()
  mm/percpu.c: correct max_distance calculation for pcpu_embed_first_chunk()
  percpu: eliminate two sparse warnings
  percpu: improve generic percpu modify-return implementation
  percpu-refcount: init ->confirm_switch member properly
  percpu_ref: allow operation mode switching operations to be called concurrently
  percpu_ref: restructure operation mode switching
  percpu_ref: unify staggered atomic switching wait behavior
  percpu_ref: reorganize __percpu_ref_switch_to_atomic() and relocate percpu_ref_switch_to_atomic()
  percpu_ref: remove unnecessary RCU grace period for staggered atomic switching confirmation
2016-10-14 11:46:25 -07:00