no need to waste storage for something that is only needed
in one place and can be deduced from protocol number.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
no need to waste storage for something that is only needed
in one place and can be deduced from protocol number.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
avoids a pointer and allows struct to be const later on.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Clang produces the following warning:
net/ipv4/netfilter/nf_nat_h323.c:553:6: error:
logical not is only applied to the left hand side of this comparison
[-Werror,-Wlogical-not-parentheses]
if (!set_h225_addr(skb, protoff, data, dataoff, taddr,
^
add parentheses after the '!' to evaluate the comparison first
add parentheses around left hand side expression to silence this warning
There's not necessarily a bug here, but it's cleaner to return early,
ex:
if (x)
return
...
rather than:
if (x == 0)
...
else
return
Also added a return code check that seemed to be missing in one
instance.
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
to be used in combination with tcp option set support to mimic
iptables TCPMSS --clamp-mss-to-pmtu.
v2: Eric Dumazet points out dst must be initialized.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This allows setting 2 and 4 byte quantities in the tcp option space.
Main purpose is to allow native replacement for xt_TCPMSS to
work around pmtu blackholes.
Writes to kind and len are now allowed at the moment, it does not seem
useful to do this as it causes corruption of the tcp option space.
We can always lift this restriction later if a use-case appears.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
so eval and uncoming eval_set versions can reuse a common helper.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The netfilter_queue_init() has been removed.
so we can remove the prototype of that.
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The root4 variable is used only when connlimit extension module has been
stored by the iptables command. and the roo6 variable is used only when
connlimit extension module has been stored by the ip6tables command.
So the root4 and roo6 variable does not be used at the same time.
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The nf_loginfo structures are only passed as the seventh argument to
nf_log_trace, which is declared as const or stored in a local const
variable. Thus the nf_loginfo structures themselves can be const.
Done with the help of Coccinelle.
// <smpl>
@r disable optional_qualifier@
identifier i;
position p;
@@
static struct nf_loginfo i@p = { ... };
@ok1@
identifier r.i;
expression list[6] es;
position p;
@@
nf_log_trace(es,&i@p,...)
@ok2@
identifier r.i;
const struct nf_loginfo *e;
position p;
@@
e = &i@p
@bad@
position p != {r.p,ok1.p,ok2.p};
identifier r.i;
struct nf_loginfo e;
@@
e@i@p
@depends on !bad disable optional_qualifier@
identifier r.i;
@@
static
+const
struct nf_loginfo i = { ... };
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When a nf_conntrack_l3/4proto parameter is not on the left hand side
of an assignment, its address is not taken, and it is not passed to a
function that may modify its fields, then it can be declared as const.
This change is useful from a documentation point of view, and can
possibly facilitate making some nf_conntrack_l3/4proto structures const
subsequently.
Done with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The target variable is not used in the compat_copy_entry_from_user().
So It can be removed.
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Discussion during NFWS 2017 in Faro has shown that the current
conntrack behaviour is unreasonable.
Even if conntrack module is loaded on behalf of a single net namespace,
its turned on for all namespaces, which is expensive. Commit
481fa37347 ("netfilter: conntrack: add nf_conntrack_default_on sysctl")
attempted to provide an alternative to the 'default on' behaviour by
adding a sysctl to change it.
However, as Eric points out, the sysctl only becomes available
once the module is loaded, and then its too late.
So we either have to move the sysctl to the core, or, alternatively,
change conntrack to become active only once the rule set requires this.
This does the latter, conntrack is only enabled when a rule needs it.
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
switch to lockless lockup. write side now also increments sequence
counter. On lookup, sample counter value and only take the lock
if we did not find a match and the counter has changed.
This avoids need to write to private area in normal (lookup) cases.
In case we detect a writer (seqretry is true) we fall back to taking
the readlock.
The readlock is also used during dumps to ensure we get a consistent
tree walk.
Similar technique (rbtree+seqlock) was used by David Howells in rxrpc.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Same conversion as for table names, use NFT_NAME_MAXLEN as upper
boundary as well.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Same conversion as for table names, use NFT_NAME_MAXLEN as upper
boundary as well.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Same conversion as for table names, use NFT_NAME_MAXLEN as upper
boundary as well.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Allocate all table names dynamically to allow for arbitrary lengths but
introduce NFT_NAME_MAXLEN as an upper sanity boundary. It's value was
chosen to allow using a domain name as per RFC 1035.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This is similar to strdup() for netlink string attributes.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nft_trace_notify() is called only from __nft_trace_packet(), which
assigns its parameter 'chain' to info->chain. __nft_trace_packet() in
turn later dereferences 'chain' unconditionally, which indicates that
it's never NULL. Same does nft_do_chain(), the only user of the tracing
infrastructure. Hence it is safe to assume the check removed here is not
needed.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
We no longer place these on a list so they can be const.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When skb is queued to userspace it leaves softirq/rcu protection.
skb->nfct (via conntrack extensions such as helper) could then reference
modules that no longer exist if the conntrack was not yet confirmed.
nf_ct_iterate_destroy() will set the DYING bit for unconfirmed
conntracks, we therefore solve this race as follows:
1. take the queue spinlock.
2. check if the conntrack is unconfirmed and has dying bit set.
In this case, we must discard skb while we're still inside
rcu read-side section.
3. If nf_ct_iterate_destroy() is called right after the packet is queued
to userspace, it will be removed from the queue via
nf_ct_iterate_destroy -> nf_queue_nf_hook_drop.
When userspace sends the verdict (nfnetlink takes rcu read lock), there
are two cases to consider:
1. nf_ct_iterate_destroy() was called while packet was out.
In this case, skb will have been removed from the queue already
and no reinject takes place as we won't find a matching entry for the
packet id.
2. nf_ct_iterate_destroy() gets called right after verdict callback
found and removed the skb from queue list.
In this case, skb->nfct is marked as dying but it is still valid.
The skb will be dropped either in nf_conntrack_confirm (we don't
insert DYING conntracks into hash table) or when we try to queue
the skb again, but either events don't occur before the rcu read lock
is dropped.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
queued skbs might be using conntrack extensions that are being removed,
such as timeout. This happens for skbs that have a skb->nfct in
unconfirmed state (i.e., not in hash table yet).
This is destructive, but there are only two use cases:
- module removal (rare)
- netns cleanup (most likely no conntracks exist, and if they do,
they are removed anyway later on).
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This also removes __nf_ct_unconfirmed_destroy() call from
nf_ct_iterate_cleanup_net, so that function can be used only
when missing conntracks from unconfirmed list isn't a problem.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
We have several spots that open-code a expect walk, add a helper
that is similar to nf_ct_iterate_destroy/nf_ct_iterate_cleanup.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Delayed workqueue causes wakeups to idle CPUs. This was
causing a power impact for devices. Use deferable work
queue instead so that gc_worker runs when CPU is active only.
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add fib expression support for netdev family. Like inet family, netdev
delegates the actual decision to the corresponding backend, either ipv4
or ipv6.
This allows to perform very early reverse path filtering, among other
things.
You can find more information about fib expression in the f6d0cbcf09
("<netfilter: nf_tables: add fib expression>") commit message.
Signed-off-by: Pablo M. Bermudo Garay <pablombg@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This is a preparatory patch for adding fib support to the netdev family.
The netdev family receives the packets from ingress hook. At this point
we have no guarantee that the ip header is linear. So this patch
replaces ip_hdr with skb_header_pointer in order to address that
possible situation.
Signed-off-by: Pablo M. Bermudo Garay <pablombg@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This is helpful for 'nft monitor' to track which process caused a given
change to the ruleset.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch removes duplicate rcu_read_lock().
1. IPVS part:
According to Julian Anastasov's mention, contexts of ipvs are described
at: http://marc.info/?l=netfilter-devel&m=149562884514072&w=2, in summary:
- packet RX/TX: does not need locks because packets come from hooks.
- sync msg RX: backup server uses RCU locks while registering new
connections.
- ip_vs_ctl.c: configuration get/set, RCU locks needed.
- xt_ipvs.c: It is a netfilter match, running from hook context.
As result, rcu_read_lock and rcu_read_unlock can be removed from:
- ip_vs_core.c: all
- ip_vs_ctl.c:
- only from ip_vs_has_real_service
- ip_vs_ftp.c: all
- ip_vs_proto_sctp.c: all
- ip_vs_proto_tcp.c: all
- ip_vs_proto_udp.c: all
- ip_vs_xmit.c: all (contains only packet processing)
2. Netfilter part:
There are three types of functions that are guaranteed the rcu_read_lock().
First, as result, functions are only called by nf_hook():
- nf_conntrack_broadcast_help(), pptp_expectfn(), set_expected_rtp_rtcp().
- tcpmss_reverse_mtu(), tproxy_laddr4(), tproxy_laddr6().
- match_lookup_rt6(), check_hlist(), hashlimit_mt_common().
- xt_osf_match_packet().
Second, functions that caller already held the rcu_read_lock().
- destroy_conntrack(), ctnetlink_conntrack_event().
- ctnl_timeout_find_get(), nfqnl_nf_hook_drop().
Third, functions that are mixed with type1 and type2.
These functions are called by nf_hook() also these are called by
ordinary functions that already held the rcu_read_lock():
- __ctnetlink_glue_build(), ctnetlink_expect_event().
- ctnetlink_proto_size().
Applied files are below:
- nf_conntrack_broadcast.c, nf_conntrack_core.c, nf_conntrack_netlink.c.
- nf_conntrack_pptp.c, nf_conntrack_sip.c, nfnetlink_cttimeout.c.
- nfnetlink_queue.c, xt_TCPMSS.c, xt_TPROXY.c, xt_addrtype.c.
- xt_connlimit.c, xt_hashlimit.c, xt_osf.c
Detailed calltrace can be found at:
http://marc.info/?l=netfilter-devel&m=149667610710350&w=2
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
These chain counters are only used by the iptables-compat tool, that
allow users to use the x_tables extensions from the existing nf_tables
framework. This patch makes nf_tables by ~5% for the general usecase,
ie. native nft users, where no chain counters are used at all.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
assuming we have lockless readers we should make sure they can only
see expectations that have already been initialized.
hlist_add_head_rcu acts as memory barrier, move it after timer setup.
Theoretically we could crash due to a del_timer() on other cpu
seeing garbage data.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pull networking fixes from David Miller:
1) BPF verifier signed/unsigned value tracking fix, from Daniel
Borkmann, Edward Cree, and Josef Bacik.
2) Fix memory allocation length when setting up calls to
->ndo_set_mac_address, from Cong Wang.
3) Add a new cxgb4 device ID, from Ganesh Goudar.
4) Fix FIB refcount handling, we have to set it's initial value before
the configure callback (which can bump it). From David Ahern.
5) Fix double-free in qcom/emac driver, from Timur Tabi.
6) A bunch of gcc-7 string format overflow warning fixes from Arnd
Bergmann.
7) Fix link level headroom tests in ip_do_fragment(), from Vasily
Averin.
8) Fix chunk walking in SCTP when iterating over error and parameter
headers. From Alexander Potapenko.
9) TCP BBR congestion control fixes from Neal Cardwell.
10) Fix SKB fragment handling in bcmgenet driver, from Doug Berger.
11) BPF_CGROUP_RUN_PROG_SOCK_OPS needs to check for null __sk, from Cong
Wang.
12) xmit_recursion in ppp driver needs to be per-device not per-cpu,
from Gao Feng.
13) Cannot release skb->dst in UDP if IP options processing needs it.
From Paolo Abeni.
14) Some netdev ioctl ifr_name[] NULL termination fixes. From Alexander
Levin and myself.
15) Revert some rtnetlink notification changes that are causing
regressions, from David Ahern.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (83 commits)
net: bonding: Fix transmit load balancing in balance-alb mode
rds: Make sure updates to cp_send_gen can be observed
net: ethernet: ti: cpsw: Push the request_irq function to the end of probe
ipv4: initialize fib_trie prior to register_netdev_notifier call.
rtnetlink: allocate more memory for dev_set_mac_address()
net: dsa: b53: Add missing ARL entries for BCM53125
bpf: more tests for mixed signed and unsigned bounds checks
bpf: add test for mixed signed and unsigned bounds checks
bpf: fix up test cases with mixed signed/unsigned bounds
bpf: allow to specify log level and reduce it for test_verifier
bpf: fix mixed signed/unsigned derived min/max value bounds
ipv6: avoid overflow of offset in ip6_find_1stfragopt
net: tehuti: don't process data if it has not been copied from userspace
Revert "rtnetlink: Do not generate notifications for CHANGEADDR event"
net: dsa: mv88e6xxx: Enable CMODE config support for 6390X
dt-binding: ptp: Add SoC compatibility strings for dte ptp clock
NET: dwmac: Make dwmac reset unconditional
net: Zero terminate ifr_name in dev_ifname().
wireless: wext: terminate ifr name coming from userspace
netfilter: fix netfilter_net_init() return
...
balance-alb mode used to have transmit dynamic load balancing feature
enabled by default. However, transmit dynamic load balancing no longer
works in balance-alb after commit 8b426dc54c ("bonding: remove
hardcoded value").
Both balance-tlb and balance-alb use the function bond_do_alb_xmit() to
send packets. This function uses the parameter tlb_dynamic_lb.
tlb_dynamic_lb used to have the default value of 1 for balance-alb, but
now the value is set to 0 except in balance-tlb.
Re-enable transmit dyanmic load balancing by initializing tlb_dynamic_lb
for balance-alb similar to balance-tlb.
Fixes: 8b426dc54c ("bonding: remove hardcoded value")
Signed-off-by: Kosuke Tatsukawa <tatsu@ab.jp.nec.com>
Acked-by: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
cp->cp_send_gen is treated as a normal variable, although it may be
used by different threads.
This is fixed by using {READ,WRITE}_ONCE when it is incremented and
READ_ONCE when it is read outside the {acquire,release}_in_xmit
protection.
Normative reference from the Linux-Kernel Memory Model:
Loads from and stores to shared (but non-atomic) variables should
be protected with the READ_ONCE(), WRITE_ONCE(), and
ACCESS_ONCE().
Clause 5.1.2.4/25 in the C standard is also relevant.
Signed-off-by: Håkon Bugge <haakon.bugge@oracle.com>
Reviewed-by: Knut Omang <knut.omang@oracle.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
print the versions of vpd and serial configuration file,
flashed to adapter, and cleanup the relevant code.
Signed-off-by: Casey Leedom <leedom@chelsio.com>
Signed-off-by: Ganesh Goudar <ganeshgr@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Push the request_irq function to the end of probe so as
to ensure all the required fields are populated in the event
of an ISR getting executed right after requesting the irq.
Currently while loading the crash kernel a crash was seen as
soon as devm_request_threaded_irq was called. This was due to
n->poll being NULL which is called as part of net_rx_action
function.
Suggested-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Net stack initialization currently initializes fib-trie after the
first call to netdevice_notifier() call. In fact fib_trie initialization
needs to happen before first rtnl_register(). It does not cause any problem
since there are no devices UP at this moment, but trying to bring 'lo'
UP at initialization would make this assumption wrong and exposes the issue.
Fixes following crash
Call Trace:
? alternate_node_alloc+0x76/0xa0
fib_table_insert+0x1b7/0x4b0
fib_magic.isra.17+0xea/0x120
fib_add_ifaddr+0x7b/0x190
fib_netdev_event+0xc0/0x130
register_netdevice_notifier+0x1c1/0x1d0
ip_fib_init+0x72/0x85
ip_rt_init+0x187/0x1e9
ip_init+0xe/0x1a
inet_init+0x171/0x26c
? ipv4_offload_init+0x66/0x66
do_one_initcall+0x43/0x160
kernel_init_freeable+0x191/0x219
? rest_init+0x80/0x80
kernel_init+0xe/0x150
ret_from_fork+0x22/0x30
Code: f6 46 23 04 74 86 4c 89 f7 e8 ae 45 01 00 49 89 c7 4d 85 ff 0f 85 7b ff ff ff 31 db eb 08 4c 89 ff e8 16 47 01 00 48 8b 44 24 38 <45> 8b 6e 14 4d 63 76 74 48 89 04 24 0f 1f 44 00 00 48 83 c4 08
RIP: kmem_cache_alloc+0xcf/0x1c0 RSP: ffff9b1500017c28
CR2: 0000000000000014
Fixes: 7b1a74fdbb ("[NETNS]: Refactor fib initialization so it can handle multiple namespaces.")
Fixes: 7f9b80529b ("[IPV4]: fib hash|trie initialization")
Signed-off-by: Mahesh Bandewar <maheshb@google.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
virtnet_set_mac_address() interprets mac address as struct
sockaddr, but upper layer only allocates dev->addr_len
which is ETH_ALEN + sizeof(sa_family_t) in this case.
We lack a unified definition for mac address, so just fix
the upper layer, this also allows drivers to interpret it
to struct sockaddr freely.
Reported-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The BCM53125 entry was missing an arl_entries member which would
basically prevent the ARL search from terminating properly. This switch
has 4 ARL entries, so add that.
Fixes: 1da6df85c6 ("net: dsa: b53: Implement ARL add/del/dump operations")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Daniel Borkmann says:
====================
BPF map value adjust fix
First patch in the series is the actual fix and the remaining
patches are just updates to selftests.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Add a couple of more test cases to BPF selftests that are related
to mixed signed and unsigned checks.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
These failed due to a bug in verifier bounds handling.
Signed-off-by: Edward Cree <ecree@solarflare.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix the few existing test cases that used mixed signed/unsigned
bounds and switch them only to one flavor. Reason why we need this
is that proper boundaries cannot be derived from mixed 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>
For the test_verifier case, it's quite hard to parse log level 2 to
figure out what's causing an issue when used to log level 1. We do
want to use bpf_verify_program() in order to simulate some of the
tests with strict alignment. So just add an argument to pass the level
and put it to 1 for test_verifier.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Edward reported that there's an issue in min/max value bounds
tracking when signed and unsigned compares both provide hints
on limits when having unknown variables. E.g. a program such
as the following should have been rejected:
0: (7a) *(u64 *)(r10 -8) = 0
1: (bf) r2 = r10
2: (07) r2 += -8
3: (18) r1 = 0xffff8a94cda93400
5: (85) call bpf_map_lookup_elem#1
6: (15) if r0 == 0x0 goto pc+7
R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0 R10=fp
7: (7a) *(u64 *)(r10 -16) = -8
8: (79) r1 = *(u64 *)(r10 -16)
9: (b7) r2 = -1
10: (2d) if r1 > r2 goto pc+3
R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0 R1=inv,min_value=0
R2=imm-1,max_value=18446744073709551615,min_align=1 R10=fp
11: (65) if r1 s> 0x1 goto pc+2
R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0 R1=inv,min_value=0,max_value=1
R2=imm-1,max_value=18446744073709551615,min_align=1 R10=fp
12: (0f) r0 += r1
13: (72) *(u8 *)(r0 +0) = 0
R0=map_value_adj(ks=8,vs=8,id=0),min_value=0,max_value=1 R1=inv,min_value=0,max_value=1
R2=imm-1,max_value=18446744073709551615,min_align=1 R10=fp
14: (b7) r0 = 0
15: (95) exit
What happens is that in the first part ...
8: (79) r1 = *(u64 *)(r10 -16)
9: (b7) r2 = -1
10: (2d) if r1 > r2 goto pc+3
... r1 carries an unsigned value, and is compared as unsigned
against a register carrying an immediate. Verifier deduces in
reg_set_min_max() that since the compare is unsigned and operation
is greater than (>), that in the fall-through/false case, r1's
minimum bound must be 0 and maximum bound must be r2. Latter is
larger than the bound and thus max value is reset back to being
'invalid' aka BPF_REGISTER_MAX_RANGE. Thus, r1 state is now
'R1=inv,min_value=0'. The subsequent test ...
11: (65) if r1 s> 0x1 goto pc+2
... is a signed compare of r1 with immediate value 1. Here,
verifier deduces in reg_set_min_max() that since the compare
is signed this time and operation is greater than (>), that
in the fall-through/false case, we can deduce that r1's maximum
bound must be 1, meaning with prior test, we result in r1 having
the following state: R1=inv,min_value=0,max_value=1. Given that
the actual value this holds is -8, the bounds are wrongly deduced.
When this is being added to r0 which holds the map_value(_adj)
type, then subsequent store access in above case will go through
check_mem_access() which invokes check_map_access_adj(), that
will then probe whether the map memory is in bounds based
on the min_value and max_value as well as access size since
the actual unknown value is min_value <= x <= max_value; commit
fce366a9dd ("bpf, verifier: fix alu ops against map_value{,
_adj} register types") provides some more explanation on the
semantics.
It's worth to note in this context that in the current code,
min_value and max_value tracking are used for two things, i)
dynamic map value access via check_map_access_adj() and since
commit 06c1c04972 ("bpf: allow helpers access to variable memory")
ii) also enforced at check_helper_mem_access() when passing a
memory address (pointer to packet, map value, stack) and length
pair to a helper and the length in this case is an unknown value
defining an access range through min_value/max_value in that
case. The min_value/max_value tracking is /not/ used in the
direct packet access case to track ranges. However, the issue
also affects case ii), for example, the following crafted program
based on the same principle must be rejected as well:
0: (b7) r2 = 0
1: (bf) r3 = r10
2: (07) r3 += -512
3: (7a) *(u64 *)(r10 -16) = -8
4: (79) r4 = *(u64 *)(r10 -16)
5: (b7) r6 = -1
6: (2d) if r4 > r6 goto pc+5
R1=ctx R2=imm0,min_value=0,max_value=0,min_align=2147483648 R3=fp-512
R4=inv,min_value=0 R6=imm-1,max_value=18446744073709551615,min_align=1 R10=fp
7: (65) if r4 s> 0x1 goto pc+4
R1=ctx R2=imm0,min_value=0,max_value=0,min_align=2147483648 R3=fp-512
R4=inv,min_value=0,max_value=1 R6=imm-1,max_value=18446744073709551615,min_align=1
R10=fp
8: (07) r4 += 1
9: (b7) r5 = 0
10: (6a) *(u16 *)(r10 -512) = 0
11: (85) call bpf_skb_load_bytes#26
12: (b7) r0 = 0
13: (95) exit
Meaning, while we initialize the max_value stack slot that the
verifier thinks we access in the [1,2] range, in reality we
pass -7 as length which is interpreted as u32 in the helper.
Thus, this issue is relevant also for the case of helper ranges.
Resetting both bounds in check_reg_overflow() in case only one
of them exceeds limits is also not enough as similar test can be
created that uses values which are within range, thus also here
learned min value in r1 is incorrect when mixed with later signed
test to create a range:
0: (7a) *(u64 *)(r10 -8) = 0
1: (bf) r2 = r10
2: (07) r2 += -8
3: (18) r1 = 0xffff880ad081fa00
5: (85) call bpf_map_lookup_elem#1
6: (15) if r0 == 0x0 goto pc+7
R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0 R10=fp
7: (7a) *(u64 *)(r10 -16) = -8
8: (79) r1 = *(u64 *)(r10 -16)
9: (b7) r2 = 2
10: (3d) if r2 >= r1 goto pc+3
R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0 R1=inv,min_value=3
R2=imm2,min_value=2,max_value=2,min_align=2 R10=fp
11: (65) if r1 s> 0x4 goto pc+2
R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0
R1=inv,min_value=3,max_value=4 R2=imm2,min_value=2,max_value=2,min_align=2 R10=fp
12: (0f) r0 += r1
13: (72) *(u8 *)(r0 +0) = 0
R0=map_value_adj(ks=8,vs=8,id=0),min_value=3,max_value=4
R1=inv,min_value=3,max_value=4 R2=imm2,min_value=2,max_value=2,min_align=2 R10=fp
14: (b7) r0 = 0
15: (95) exit
This leaves us with two options for fixing this: i) to invalidate
all prior learned information once we switch signed context, ii)
to track min/max signed and unsigned boundaries separately as
done in [0]. (Given latter introduces major changes throughout
the whole verifier, it's rather net-next material, thus this
patch follows option i), meaning we can derive bounds either
from only signed tests or only unsigned tests.) There is still the
case of adjust_reg_min_max_vals(), where we adjust bounds on ALU
operations, meaning programs like the following where boundaries
on the reg get mixed in context later on when bounds are merged
on the dst reg must get rejected, too:
0: (7a) *(u64 *)(r10 -8) = 0
1: (bf) r2 = r10
2: (07) r2 += -8
3: (18) r1 = 0xffff89b2bf87ce00
5: (85) call bpf_map_lookup_elem#1
6: (15) if r0 == 0x0 goto pc+6
R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0 R10=fp
7: (7a) *(u64 *)(r10 -16) = -8
8: (79) r1 = *(u64 *)(r10 -16)
9: (b7) r2 = 2
10: (3d) if r2 >= r1 goto pc+2
R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0 R1=inv,min_value=3
R2=imm2,min_value=2,max_value=2,min_align=2 R10=fp
11: (b7) r7 = 1
12: (65) if r7 s> 0x0 goto pc+2
R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0 R1=inv,min_value=3
R2=imm2,min_value=2,max_value=2,min_align=2 R7=imm1,max_value=0 R10=fp
13: (b7) r0 = 0
14: (95) exit
from 12 to 15: R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0
R1=inv,min_value=3 R2=imm2,min_value=2,max_value=2,min_align=2 R7=imm1,min_value=1 R10=fp
15: (0f) r7 += r1
16: (65) if r7 s> 0x4 goto pc+2
R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0 R1=inv,min_value=3
R2=imm2,min_value=2,max_value=2,min_align=2 R7=inv,min_value=4,max_value=4 R10=fp
17: (0f) r0 += r7
18: (72) *(u8 *)(r0 +0) = 0
R0=map_value_adj(ks=8,vs=8,id=0),min_value=4,max_value=4 R1=inv,min_value=3
R2=imm2,min_value=2,max_value=2,min_align=2 R7=inv,min_value=4,max_value=4 R10=fp
19: (b7) r0 = 0
20: (95) exit
Meaning, in adjust_reg_min_max_vals() we must also reset range
values on the dst when src/dst registers have mixed signed/
unsigned derived min/max value bounds with one unbounded value
as otherwise they can be added together deducing false boundaries.
Once both boundaries are established from either ALU ops or
compare operations w/o mixing signed/unsigned insns, then they
can safely be added to other regs also having both boundaries
established. Adding regs with one unbounded side to a map value
where the bounded side has been learned w/o mixing ops is
possible, but the resulting map value won't recover from that,
meaning such op is considered invalid on the time of actual
access. Invalid bounds are set on the dst reg in case i) src reg,
or ii) in case dst reg already had them. The only way to recover
would be to perform i) ALU ops but only 'add' is allowed on map
value types or ii) comparisons, but these are disallowed on
pointers in case they span a range. This is fine as only BPF_JEQ
and BPF_JNE may be performed on PTR_TO_MAP_VALUE_OR_NULL registers
which potentially turn them into PTR_TO_MAP_VALUE type depending
on the branch, so only here min/max value cannot be invalidated
for them.
In terms of state pruning, value_from_signed is considered
as well in states_equal() when dealing with adjusted map values.
With regards to breaking existing programs, there is a small
risk, but use-cases are rather quite narrow where this could
occur and mixing compares probably unlikely.
Joint work with Josef and Edward.
[0] https://lists.iovisor.org/pipermail/iovisor-dev/2017-June/000822.html
Fixes: 484611357c ("bpf: allow access into map value arrays")
Reported-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
- Fix the average CPU load computations in the intel_pstate driver
on Knights Landing (Xeon Phi) processors that require an extra
factor to compensate for a rate change differences between the
TSC and MPERF which is missing (Srinivas Pandruvada).
- Fix an initialization ordering issue in the generic power domains
(genpd) framework (Sudeep Holla).
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Merge tag 'pm-4.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull power management fixes from Rafael Wysocki:
"These are two stable-candidate fixes for the intel_pstate driver and
the generic power domains (genpd) framework.
Specifics:
- Fix the average CPU load computations in the intel_pstate driver on
Knights Landing (Xeon Phi) processors that require an extra factor
to compensate for a rate change differences between the TSC and
MPERF which is missing (Srinivas Pandruvada).
- Fix an initialization ordering issue in the generic power domains
(genpd) framework (Sudeep Holla)"
* tag 'pm-4.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
PM / Domains: defer dev_pm_domain_set() until genpd->attach_dev succeeds if present
cpufreq: intel_pstate: Correct the busy calculation for KNL