1
0
Fork 0
Fork of alistair23 Linux kernel for reMarkable from https://github.com/alistair23/linux
 
 
 
 
 
 
Go to file
Kuppuswamy Sathyanarayanan efb5f7b106 drivers: base: Fix NULL pointer exception in __platform_driver_probe() if a driver developer is foolish
[ Upstream commit 388bcc6ecc ]

If platform bus driver registration is failed then, accessing
platform bus spin lock (&drv->driver.bus->p->klist_drivers.k_lock)
in __platform_driver_probe() without verifying the return value
__platform_driver_register() can lead to NULL pointer exception.

So check the return value before attempting the spin lock.

One such example is below:

For a custom usecase, I have intentionally failed the platform bus
registration and I expected all the platform device/driver
registrations to fail gracefully. But I came across this panic
issue.

[    1.331067] BUG: kernel NULL pointer dereference, address: 00000000000000c8
[    1.331118] #PF: supervisor write access in kernel mode
[    1.331163] #PF: error_code(0x0002) - not-present page
[    1.331208] PGD 0 P4D 0
[    1.331233] Oops: 0002 [#1] PREEMPT SMP
[    1.331268] CPU: 3 PID: 1 Comm: swapper/0 Tainted: G        W         5.6.0-00049-g670d35fb0144 #165
[    1.331341] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
[    1.331406] RIP: 0010:_raw_spin_lock+0x15/0x30
[    1.331588] RSP: 0000:ffffc9000001be70 EFLAGS: 00010246
[    1.331632] RAX: 0000000000000000 RBX: 00000000000000c8 RCX: 0000000000000001
[    1.331696] RDX: 0000000000000001 RSI: 0000000000000092 RDI: 0000000000000000
[    1.331754] RBP: 00000000ffffffed R08: 0000000000000501 R09: 0000000000000001
[    1.331817] R10: ffff88817abcc520 R11: 0000000000000670 R12: 00000000ffffffed
[    1.331881] R13: ffffffff82dbc268 R14: ffffffff832f070a R15: 0000000000000000
[    1.331945] FS:  0000000000000000(0000) GS:ffff88817bd80000(0000) knlGS:0000000000000000
[    1.332008] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    1.332062] CR2: 00000000000000c8 CR3: 000000000681e001 CR4: 00000000003606e0
[    1.332126] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[    1.332189] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[    1.332252] Call Trace:
[    1.332281]  __platform_driver_probe+0x92/0xee
[    1.332323]  ? rtc_dev_init+0x2b/0x2b
[    1.332358]  cmos_init+0x37/0x67
[    1.332396]  do_one_initcall+0x7d/0x168
[    1.332428]  kernel_init_freeable+0x16c/0x1c9
[    1.332473]  ? rest_init+0xc0/0xc0
[    1.332508]  kernel_init+0x5/0x100
[    1.332543]  ret_from_fork+0x1f/0x30
[    1.332579] CR2: 00000000000000c8
[    1.332616] ---[ end trace 3bd87f12e9010b87 ]---
[    1.333549] note: swapper/0[1] exited with preempt_count 1
[    1.333592] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009
[    1.333736] Kernel Offset: disabled

Note, this can only be triggered if a driver errors out from this call,
which should never happen.  If it does, the driver needs to be fixed.

Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Link: https://lore.kernel.org/r/20200408214003.3356-1-sathyanarayanan.kuppuswamy@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-06-24 17:50:24 +02:00
Documentation dt-bindings: display: mediatek: control dpi pins mode to avoid leakage 2020-06-22 09:30:58 +02:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
arch arm64: dts: qcom: fix pm8150 gpio interrupts 2020-06-24 17:50:21 +02:00
block iocost: don't let vrate run wild while there's no saturation signal 2020-06-22 09:31:06 +02:00
certs PKCS#7: Refactor verify_pkcs7_signature() 2019-08-05 18:40:18 -04:00
crypto crypto: drbg - fix error return code in drbg_alloc_state() 2020-06-17 16:40:31 +02:00
drivers drivers: base: Fix NULL pointer exception in __platform_driver_probe() if a driver developer is foolish 2020-06-24 17:50:24 +02:00
fs virtiofs: schedule blocking async replies in separate worker 2020-06-24 17:50:21 +02:00
include usb: gadget: core: sync interrupt before unbind the udc 2020-06-24 17:50:16 +02:00
init x86: Fix early boot crash on gcc-10, third try 2020-05-20 08:20:34 +02:00
ipc ipc/util.c: sysvipc_find_ipc() incorrectly updates position index 2020-05-20 08:20:16 +02:00
kernel kernel/cpu_pm: Fix uninitted local in cpu_pm 2020-06-22 09:31:22 +02:00
lib kasan: stop tests being eliminated as dead code with FORTIFY_SOURCE 2020-06-22 09:31:12 +02:00
mm mm: call cond_resched() from deferred_init_memmap() 2020-06-22 09:31:14 +02:00
net bpf, sockhash: Fix memory leak when unlinking sockets in sock_hash_free 2020-06-24 17:50:19 +02:00
samples samples: bpf: Fix build error 2020-06-03 08:21:15 +02:00
scripts mksysmap: Fix the mismatch of '.L' symbols in System.map 2020-06-24 17:50:19 +02:00
security apparmor: fix nnp subset test for unconfined 2020-06-24 17:50:20 +02:00
sound ASoC: max98373: reorder max98373_reset() in resume 2020-06-24 17:50:23 +02:00
tools perf symbols: Fix kernel maps for kcore and eBPF 2020-06-22 09:31:27 +02:00
usr initramfs: restore default compression behavior 2020-04-08 09:08:38 +02:00
virt KVM: arm64: Save the host's PtrAuth keys in non-preemptible context 2020-06-17 16:40:38 +02:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Modules updates for v5.4 2019-09-22 10:34:46 -07:00
.mailmap ARM: SoC fixes 2019-11-10 13:41:59 -08:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS: Remove Simon as Renesas SoC Co-Maintainer 2019-10-10 08:12:51 -07:00
Kbuild kbuild: do not descend to ./Kbuild when cleaning 2019-08-21 21:03:58 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS MAINTAINERS: Update drm/i915 bug filing URL 2020-02-28 17:22:19 +01:00
Makefile Linux 5.4.48 2020-06-22 09:31:27 +02:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.