[ Upstream commit cc73bbab4b1fb8a4f53a24645871dafa5f81266a ]
The Record Route IP option records the addresses of the routers that
routed the packet. In the case of forwarded packets, the kernel performs
a route lookup via fib_lookup() and fills in the preferred source
address of the matched route.
The lookup is performed with the DS field of the forwarded packet, but
using the RT_TOS() macro which only masks one of the two ECN bits. If
the packet is ECT(0) or CE, the matched route might be different than
the route via which the packet was forwarded as the input path masks
both of the ECN bits, resulting in the wrong address being filled in the
Record Route option.
Fix by masking both of the ECN bits.
Fixes: 8e36360ae876 ("ipv4: Remove route key identity dependencies in ip_rt_get_source().")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Link: https://patch.msgid.link/20240718123407.434778-1-idosch@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 96f887a612e4cda89efc3f54bc10c1997e3ab0e9 ]
xmit() functions should consume skb or return error codes in error
paths.
When the configuration "CONFIG_INET_ESPINTCP" is not set, the
implementation of the function "esp_output_tail_tcp" violates this rule.
The function frees the skb and returns the error code.
This change removes the kfree_skb from both functions, for both
esp4 and esp6.
WARN_ON is added because esp_output_tail_tcp() should never be called if
CONFIG_INET_ESPINTCP is not set.
This bug was discovered and resolved using Coverity Static Analysis
Security Testing (SAST) by Synopsys, Inc.
Fixes: e27cca96cd68 ("xfrm: add espintcp (RFC 8229)")
Signed-off-by: Hagar Hemdan <hagarhem@amazon.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Forcing TCP no-delay will disable Nagle's algorithm, which basically collects small outgoing packets to send all at once. Disabling this will lead to all the packets being sent at their respective times, leading to better latency.
Read https://brooker.co.za/blog/2024/05/09/nagle.html for details.
Signed-off-by: prathamdubey2005 <134331217+prathamdubey2005@users.noreply.github.com>
commit 97a9063518f198ec0adb2ecb89789de342bb8283 upstream.
If a TCP socket is using TCP_USER_TIMEOUT, and the other peer
retracted its window to zero, tcp_retransmit_timer() can
retransmit a packet every two jiffies (2 ms for HZ=1000),
for about 4 minutes after TCP_USER_TIMEOUT has 'expired'.
The fix is to make sure tcp_rtx_probe0_timed_out() takes
icsk->icsk_user_timeout into account.
Before blamed commit, the socket would not timeout after
icsk->icsk_user_timeout, but would use standard exponential
backoff for the retransmits.
Also worth noting that before commit e89688e3e978 ("net: tcp:
fix unexcepted socket die when snd_wnd is 0"), the issue
would last 2 minutes instead of 4.
Fixes: b701a99e431d ("tcp: Add tcp_clamp_rto_to_user_timeout() helper to improve accuracy")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Reviewed-by: Jon Maxwell <jmaxwell37@gmail.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20240710001402.2758273-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 36534d3c54537bf098224a32dc31397793d4594d upstream.
Due to timer wheel implementation, a timer will usually fire
after its schedule.
For instance, for HZ=1000, a timeout between 512ms and 4s
has a granularity of 64ms.
For this range of values, the extra delay could be up to 63ms.
For TCP, this means that tp->rcv_tstamp may be after
inet_csk(sk)->icsk_timeout whenever the timer interrupt
finally triggers, if one packet came during the extra delay.
We need to make sure tcp_rtx_probe0_timed_out() handles this case.
Fixes: e89688e3e978 ("net: tcp: fix unexcepted socket die when snd_wnd is 0")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Menglong Dong <imagedong@tencent.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Link: https://lore.kernel.org/r/20240607125652.1472540-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 0ec986ed7bab6801faed1440e8839dcc710331ff ]
Loss recovery undo_retrans bookkeeping had a long-standing bug where a
DSACK from a spurious TLP retransmit packet could cause an erroneous
undo of a fast recovery or RTO recovery that repaired a single
really-lost packet (in a sequence range outside that of the TLP
retransmit). Basically, because the loss recovery state machine didn't
account for the fact that it sent a TLP retransmit, the DSACK for the
TLP retransmit could erroneously be implicitly be interpreted as
corresponding to the normal fast recovery or RTO recovery retransmit
that plugged a real hole, thus resulting in an improper undo.
For example, consider the following buggy scenario where there is a
real packet loss but the congestion control response is improperly
undone because of this bug:
+ send packets P1, P2, P3, P4
+ P1 is really lost
+ send TLP retransmit of P4
+ receive SACK for original P2, P3, P4
+ enter fast recovery, fast-retransmit P1, increment undo_retrans to 1
+ receive DSACK for TLP P4, decrement undo_retrans to 0, undo (bug!)
+ receive cumulative ACK for P1-P4 (fast retransmit plugged real hole)
The fix: when we initialize undo machinery in tcp_init_undo(), if
there is a TLP retransmit in flight, then increment tp->undo_retrans
so that we make sure that we receive a DSACK corresponding to the TLP
retransmit, as well as DSACKs for all later normal retransmits, before
triggering a loss recovery undo. Note that we also have to move the
line that clears tp->tlp_high_seq for RTO recovery, so that upon RTO
we remember the tp->tlp_high_seq value until tcp_init_undo() and clear
it only afterward.
Also note that the bug dates back to the original 2013 TLP
implementation, commit 6ba8a3b19e76 ("tcp: Tail loss probe (TLP)").
However, this patch will only compile and work correctly with kernels
that have tp->tlp_retrans, which was added only in v5.8 in 2020 in
commit 76be93fc0702 ("tcp: allow at most one TLP probe per flight").
So we associate this fix with that later commit.
Fixes: 76be93fc0702 ("tcp: allow at most one TLP probe per flight")
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Kevin Yang <yyd@google.com>
Link: https://patch.msgid.link/20240703171246.1739561-1-ncardwell.sw@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit d8616ee2affcff37c5d315310da557a694a3303d upstream.
During TCP sockmap redirect pressure test, the following warning is triggered:
WARNING: CPU: 3 PID: 2145 at net/core/stream.c:205 sk_stream_kill_queues+0xbc/0xd0
CPU: 3 PID: 2145 Comm: iperf Kdump: loaded Tainted: G W 5.10.0+ #9
Call Trace:
inet_csk_destroy_sock+0x55/0x110
inet_csk_listen_stop+0xbb/0x380
tcp_close+0x41b/0x480
inet_release+0x42/0x80
__sock_release+0x3d/0xa0
sock_close+0x11/0x20
__fput+0x9d/0x240
task_work_run+0x62/0x90
exit_to_user_mode_prepare+0x110/0x120
syscall_exit_to_user_mode+0x27/0x190
entry_SYSCALL_64_after_hwframe+0x44/0xa9
The reason we observed is that:
When the listener is closing, a connection may have completed the three-way
handshake but not accepted, and the client has sent some packets. The child
sks in accept queue release by inet_child_forget()->inet_csk_destroy_sock(),
but psocks of child sks have not released.
To fix, add sock_map_destroy to release psocks.
Signed-off-by: Wang Yufen <wangyufen@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20220524075311.649153-1-wangyufen@huawei.com
[ Conflict in include/linux/bpf.h due to function declaration position
and remove non-existed sk_psock_stop helper from sock_map_destroy. ]
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 66be40e622e177316ae81717aa30057ba9e61dff ]
I don't see anything checking that TCP_METRICS_ATTR_SADDR_IPV4
is at least 4 bytes long, and the policy doesn't have an entry
for this attribute at all (neither does it for IPv6 but v6 is
manually validated).
Reviewed-by: Eric Dumazet <edumazet@google.com>
Fixes: 3e7013ddf55a ("tcp: metrics: Allow selective get/del of tcp-metrics based on src IP")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a6458ab7fd4f427d4f6f54380453ad255b7fde83 ]
In some production workloads we noticed that connections could
sometimes close extremely prematurely with ETIMEDOUT after
transmitting only 1 TLP and RTO retransmission (when we would normally
expect roughly tcp_retries2 = TCP_RETR2 = 15 RTOs before a connection
closes with ETIMEDOUT).
From tracing we determined that these workloads can suffer from a
scenario where in fast recovery, after some retransmits, a DSACK undo
can happen at a point where the scoreboard is totally clear (we have
retrans_out == sacked_out == lost_out == 0). In such cases, calling
tcp_try_keep_open() means that we do not execute any code path that
clears tp->retrans_stamp to 0. That means that tp->retrans_stamp can
remain erroneously set to the start time of the undone fast recovery,
even after the fast recovery is undone. If minutes or hours elapse,
and then a TLP/RTO/RTO sequence occurs, then the start_ts value in
retransmits_timed_out() (which is from tp->retrans_stamp) will be
erroneously ancient (left over from the fast recovery undone via
DSACKs). Thus this ancient tp->retrans_stamp value can cause the
connection to die very prematurely with ETIMEDOUT via
tcp_write_err().
The fix: we change DSACK undo in fast recovery (TCP_CA_Recovery) to
call tcp_try_to_open() instead of tcp_try_keep_open(). This ensures
that if no retransmits are in flight at the time of DSACK undo in fast
recovery then we properly zero retrans_stamp. Note that calling
tcp_try_to_open() is more consistent with other loss recovery
behavior, since normal fast recovery (CA_Recovery) and RTO recovery
(CA_Loss) both normally end when tp->snd_una meets or exceeds
tp->high_seq and then in tcp_fastretrans_alert() the "default" switch
case executes tcp_try_to_open(). Also note that by inspection this
change to call tcp_try_to_open() implies at least one other nice bug
fix, where now an ECE-marked DSACK that causes an undo will properly
invoke tcp_enter_cwr() rather than ignoring the ECE mark.
Fixes: c7d9d6a185a7 ("tcp: undo on DSACK during recovery")
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit f49cd2f4d6170d27a2c61f1fecb03d8a70c91f57 upstream.
setsockopt(IPV6_ADDRFORM) and tcp_v6_connect() change icsk->icsk_af_ops
under lock_sock(), but tcp_(get|set)sockopt() read it locklessly. To
avoid load/store tearing, we need to add READ_ONCE() and WRITE_ONCE()
for the reads and writes.
Thanks to Eric Dumazet for providing the syzbot report:
BUG: KCSAN: data-race in tcp_setsockopt / tcp_v6_connect
write to 0xffff88813c624518 of 8 bytes by task 23936 on cpu 0:
tcp_v6_connect+0x5b3/0xce0 net/ipv6/tcp_ipv6.c:240
__inet_stream_connect+0x159/0x6d0 net/ipv4/af_inet.c:660
inet_stream_connect+0x44/0x70 net/ipv4/af_inet.c:724
__sys_connect_file net/socket.c:1976 [inline]
__sys_connect+0x197/0x1b0 net/socket.c:1993
__do_sys_connect net/socket.c:2003 [inline]
__se_sys_connect net/socket.c:2000 [inline]
__x64_sys_connect+0x3d/0x50 net/socket.c:2000
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
read to 0xffff88813c624518 of 8 bytes by task 23937 on cpu 1:
tcp_setsockopt+0x147/0x1c80 net/ipv4/tcp.c:3789
sock_common_setsockopt+0x5d/0x70 net/core/sock.c:3585
__sys_setsockopt+0x212/0x2b0 net/socket.c:2252
__do_sys_setsockopt net/socket.c:2263 [inline]
__se_sys_setsockopt net/socket.c:2260 [inline]
__x64_sys_setsockopt+0x62/0x70 net/socket.c:2260
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
value changed: 0xffffffff8539af68 -> 0xffffffff8539aff8
Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 23937 Comm: syz-executor.5 Not tainted
6.0.0-rc4-syzkaller-00331-g4ed9c1e971b1-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine,
BIOS Google 08/26/2022
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzbot <syzkaller@googlegroups.com>
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Kazunori Kobayashi <kazunori.kobayashi@miraclelinux.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 364f997b5cfe1db0d63a390fe7c801fa2b3115f6 upstream.
Commit 086d49058cd8 ("ipv6: annotate some data-races around sk->sk_prot")
fixed some data-races around sk->sk_prot but it was not enough.
Some functions in inet6_(stream|dgram)_ops still access sk->sk_prot
without lock_sock() or rtnl_lock(), so they need READ_ONCE() to avoid
load tearing.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Kazunori Kobayashi <kazunori.kobayashi@miraclelinux.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 9f36169912331fa035d7b73a91252d7c2512eb1a ]
As evident from the definition of ip_options_get(), the IP option
IPOPT_END is used to pad the IP option data array, not IPOPT_NOP. Yet
the loop that walks the IP options to determine the total IP options
length in cipso_v4_delopt() doesn't take IPOPT_END into account.
Fix it by recognizing the IPOPT_END value as the end of actual options.
Fixes: 014ab19a69c3 ("selinux: Set socket NetLabel based on connection endpoint")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a46d0ea5c94205f40ecf912d1bb7806a8a64704f ]
According to RFC 1213, we should also take CLOSE-WAIT sockets into
consideration:
"tcpCurrEstab OBJECT-TYPE
...
The number of TCP connections for which the current state
is either ESTABLISHED or CLOSE- WAIT."
After this, CurrEstab counter will display the total number of
ESTABLISHED and CLOSE-WAIT sockets.
The logic of counting
When we increment the counter?
a) if we change the state to ESTABLISHED.
b) if we change the state from SYN-RECEIVED to CLOSE-WAIT.
When we decrement the counter?
a) if the socket leaves ESTABLISHED and will never go into CLOSE-WAIT,
say, on the client side, changing from ESTABLISHED to FIN-WAIT-1.
b) if the socket leaves CLOSE-WAIT, say, on the server side, changing
from CLOSE-WAIT to LAST-ACK.
Please note: there are two chances that old state of socket can be changed
to CLOSE-WAIT in tcp_fin(). One is SYN-RECV, the other is ESTABLISHED.
So we have to take care of the former case.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 92f1655aa2b2294d0b49925f3b875a634bd3b59e upstream.
__dst_negative_advice() does not enforce proper RCU rules when
sk->dst_cache must be cleared, leading to possible UAF.
RCU rules are that we must first clear sk->sk_dst_cache,
then call dst_release(old_dst).
Note that sk_dst_reset(sk) is implementing this protocol correctly,
while __dst_negative_advice() uses the wrong order.
Given that ip6_negative_advice() has special logic
against RTF_CACHE, this means each of the three ->negative_advice()
existing methods must perform the sk_dst_reset() themselves.
Note the check against NULL dst is centralized in
__dst_negative_advice(), there is no need to duplicate
it in various callbacks.
Many thanks to Clement Lecigne for tracking this issue.
This old bug became visible after the blamed commit, using UDP sockets.
Fixes: a87cb3e48ee8 ("net: Facility to report route quality of connected sockets")
Reported-by: Clement Lecigne <clecigne@google.com>
Diagnosed-by: Clement Lecigne <clecigne@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Tom Herbert <tom@herbertland.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20240528114353.1794151-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[Lee: Stable backport]
Signed-off-by: Lee Jones <lee@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 21a673bddc8fd4873c370caf9ae70ffc6d47e8d3 ]
syzbot reports:
general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
[..]
RIP: 0010:nf_tproxy_laddr4+0xb7/0x340 net/ipv4/netfilter/nf_tproxy_ipv4.c:62
Call Trace:
nft_tproxy_eval_v4 net/netfilter/nft_tproxy.c:56 [inline]
nft_tproxy_eval+0xa9a/0x1a00 net/netfilter/nft_tproxy.c:168
__in_dev_get_rcu() can return NULL, so check for this.
Reported-and-tested-by: syzbot+b94a6818504ea90d7661@syzkaller.appspotmail.com
Fixes: cc6eb4338569 ("tproxy: use the interface primary IP address as a default value for --on-ip")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ec00ed472bdb7d0af840da68c8c11bff9f4d9caa ]
While testing TCP performance with latest trees,
I saw suspect SOCKET_BACKLOG drops.
tcp_add_backlog() computes its limit with :
limit = (u32)READ_ONCE(sk->sk_rcvbuf) +
(u32)(READ_ONCE(sk->sk_sndbuf) >> 1);
limit += 64 * 1024;
This does not take into account that sk->sk_backlog.len
is reset only at the very end of __release_sock().
Both sk->sk_backlog.len and sk->sk_rmem_alloc could reach
sk_rcvbuf in normal conditions.
We should double sk->sk_rcvbuf contribution in the formula
to absorb bubbles in the backlog, which happen more often
for very fast flows.
This change maintains decent protection against abuses.
Fixes: c377411f2494 ("net: sk_add_backlog() take rmem_alloc into account")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240423125620.3309458-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 50aee97d15113b95a68848db1f0cb2a6c09f753a ]
We've observed a 7-12% performance regression in iperf3 UDP ipv4 and
ipv6 tests with multiple sockets on Zen3 cpus, which we traced back to
commit f0ea27e7bfe1 ("udp: re-score reuseport groups when connected
sockets are present"). The failing tests were those that would spawn
UDP sockets per-cpu on systems that have a high number of cpus.
Unsurprisingly, it is not caused by the extra re-scoring of the reused
socket, but due to the compiler no longer inlining compute_score, once
it has the extra call site in udp4_lib_lookup2. This is augmented by
the "Safe RET" mitigation for SRSO, needed in our Zen3 cpus.
We could just explicitly inline it, but compute_score() is quite a large
function, around 300b. Inlining in two sites would almost double
udp4_lib_lookup2, which is a silly thing to do just to workaround a
mitigation. Instead, this patch shuffles the code a bit to avoid the
multiple calls to compute_score. Since it is a static function used in
one spot, the compiler can safely fold it in, as it did before, without
increasing the text size.
With this patch applied I ran my original iperf3 testcases. The failing
cases all looked like this (ipv4):
iperf3 -c 127.0.0.1 --udp -4 -f K -b $R -l 8920 -t 30 -i 5 -P 64 -O 2
where $R is either 1G/10G/0 (max, unlimited). I ran 3 times each.
baseline is v6.9-rc3. harmean == harmonic mean; CV == coefficient of
variation.
ipv4:
1G 10G MAX
HARMEAN (CV) HARMEAN (CV) HARMEAN (CV)
baseline 1743852.66(0.0208) 1725933.02(0.0167) 1705203.78(0.0386)
patched 1968727.61(0.0035) 1962283.22(0.0195) 1923853.50(0.0256)
ipv6:
1G 10G MAX
HARMEAN (CV) HARMEAN (CV) HARMEAN (CV)
baseline 1729020.03(0.0028) 1691704.49(0.0243) 1692251.34(0.0083)
patched 1900422.19(0.0067) 1900968.01(0.0067) 1568532.72(0.1519)
This restores the performance we had before the change above with this
benchmark. We obviously don't expect any real impact when mitigations
are disabled, but just to be sure it also doesn't regresses:
mitigations=off ipv4:
1G 10G MAX
HARMEAN (CV) HARMEAN (CV) HARMEAN (CV)
baseline 3230279.97(0.0066) 3229320.91(0.0060) 2605693.19(0.0697)
patched 3242802.36(0.0073) 3239310.71(0.0035) 2502427.19(0.0882)
Cc: Lorenz Bauer <lmb@isovalent.com>
Fixes: f0ea27e7bfe1 ("udp: re-score reuseport groups when connected sockets are present")
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0f495f7617229772403e683033abc473f0f0553c ]
There are currently four copies of reuseport_lookup: one each for
(TCP, UDP)x(IPv4, IPv6). This forces us to duplicate all callers of
those functions as well. This is already the case for sk_lookup
helpers (inet,inet6,udp4,udp6)_lookup_run_bpf.
There are two differences between the reuseport_lookup helpers:
1. They call different hash functions depending on protocol
2. UDP reuseport_lookup checks that sk_state != TCP_ESTABLISHED
Move the check for sk_state into the caller and use the INDIRECT_CALL
infrastructure to cut down the helpers to one per IP version.
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Lorenz Bauer <lmb@isovalent.com>
Link: https://lore.kernel.org/r/20230720-so-reuseport-v6-4-7021b683cdae@isovalent.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Stable-dep-of: 50aee97d1511 ("udp: Avoid call to compute_score on multiple sites")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ce796e60b3b196b61fcc565df195443cbb846ef0 ]
Rename the existing reuseport helpers for IPv4 and IPv6 so that they
can be invoked in the follow up commit. Export them so that building
DCCP and IPv6 as a module works.
No change in functionality.
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Lorenz Bauer <lmb@isovalent.com>
Link: https://lore.kernel.org/r/20230720-so-reuseport-v6-3-7021b683cdae@isovalent.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Stable-dep-of: 50aee97d1511 ("udp: Avoid call to compute_score on multiple sites")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 58fbfecab965014b6e3cc956a76b4a96265a1add ]
The software GRO path for esp transport mode uses skb_mac_header_rebuild
prior to re-injecting the packet via the xfrm_napi_dev. This only
copies skb->mac_len bytes of header which may not be sufficient if the
packet contains 802.1Q tags or other VLAN tags. Worse copying only the
initial header will leave a packet marked as being VLAN tagged but
without the corresponding tag leading to mangling when it is later
untagged.
The VLAN tags are important when receiving the decrypted esp transport
mode packet after GRO processing to ensure it is received on the correct
interface.
Therefore record the full mac header length in xfrm*_transport_input for
later use in corresponding xfrm*_transport_finish to copy the entire mac
header when rebuilding the mac header for GRO. The skb->data pointer is
left pointing skb->mac_header bytes after the start of the mac header as
is expected by the network stack and network and transport header
offsets reset to this location.
Fixes: 7785bba299a8 ("esp: Add a software GRO codepath")
Signed-off-by: Paul Davey <paul.davey@alliedtelesis.co.nz>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5babae777c61aa8a8679d59d3cdc54165ad96d42 ]
GRO-GSO path is supposed to be transparent and as such L3 flush checks are
relevant to all UDP flows merging in GRO. This patch uses the same logic
and code from tcp_gro_receive, terminating merge if flush is non zero.
Fixes: e20cf8d3f1f7 ("udp: implement GRO for plain UDP sockets.")
Signed-off-by: Richard Gobert <richardbgobert@gmail.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 680d11f6e5427b6af1321932286722d24a8b16c1 upstream.
If "udp_cmsg_send()" returned 0 (i.e. only UDP cmsg),
"connected" should not be set to 0. Otherwise it stops
the connected socket from using the cached route.
Fixes: 2e8de8576343 ("udp: add gso segment cmsg")
Signed-off-by: Yick Xie <yick.xie@gmail.com>
Cc: stable@vger.kernel.org
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/20240418170610.867084-1-yick.xie@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Yick Xie <yick.xie@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1c4e97dd2d3c9a3e84f7e26346aa39bc426d3249 upstream.
inet_twsk_purge() uses rcu to find TIME_WAIT and NEW_SYN_RECV
objects to purge.
These objects use SLAB_TYPESAFE_BY_RCU semantic and need special
care. We need to use refcount_inc_not_zero(&sk->sk_refcnt).
Reuse the existing correct logic I wrote for TIME_WAIT,
because both structures have common locations for
sk_state, sk_family, and netns pointer.
If after the refcount_inc_not_zero() the object fields longer match
the keys, use sock_gen_put(sk) to release the refcount.
Then we can call inet_twsk_deschedule_put() for TIME_WAIT,
inet_csk_reqsk_queue_drop_and_put() for NEW_SYN_RECV sockets,
with BH disabled.
Then we need to restart the loop because we had drop rcu_read_lock().
Fixes: 740ea3c4a0b2 ("tcp: Clean up kernel listener's reqsk in inet_twsk_purge()")
Link: https://lore.kernel.org/netdev/CANn89iLvFuuihCtt9PME2uS1WJATnf5fKjDToa1WzVnRzHnPfg@mail.gmail.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240308200122.64357-2-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[shaozhengchao: resolved conflicts in 5.10]
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 740ea3c4a0b2e326b23d7cdf05472a0e92aa39bc upstream.
Eric Dumazet reported a use-after-free related to the per-netns ehash
series. [0]
When we create a TCP socket from userspace, the socket always holds a
refcnt of the netns. This guarantees that a reqsk timer is always fired
before netns dismantle. Each reqsk has a refcnt of its listener, so the
listener is not freed before the reqsk, and the net is not freed before
the listener as well.
OTOH, when in-kernel users create a TCP socket, it might not hold a refcnt
of its netns. Thus, a reqsk timer can be fired after the netns dismantle
and access freed per-netns ehash.
To avoid the use-after-free, we need to clean up TCP_NEW_SYN_RECV sockets
in inet_twsk_purge() if the netns uses a per-netns ehash.
[0]: https://lore.kernel.org/netdev/CANn89iLXMup0dRD_Ov79Xt8N9FM0XdhCHEN05sf3eLwxKweM6w@mail.gmail.com/
BUG: KASAN: use-after-free in tcp_or_dccp_get_hashinfo
include/net/inet_hashtables.h:181 [inline]
BUG: KASAN: use-after-free in reqsk_queue_unlink+0x320/0x350
net/ipv4/inet_connection_sock.c:913
Read of size 8 at addr ffff88807545bd80 by task syz-executor.2/8301
CPU: 1 PID: 8301 Comm: syz-executor.2 Not tainted
6.0.0-syzkaller-02757-gaf7d23f9d96a #0
Hardware name: Google Google Compute Engine/Google Compute Engine,
BIOS Google 09/22/2022
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:317 [inline]
print_report.cold+0x2ba/0x719 mm/kasan/report.c:433
kasan_report+0xb1/0x1e0 mm/kasan/report.c:495
tcp_or_dccp_get_hashinfo include/net/inet_hashtables.h:181 [inline]
reqsk_queue_unlink+0x320/0x350 net/ipv4/inet_connection_sock.c:913
inet_csk_reqsk_queue_drop net/ipv4/inet_connection_sock.c:927 [inline]
inet_csk_reqsk_queue_drop_and_put net/ipv4/inet_connection_sock.c:939 [inline]
reqsk_timer_handler+0x724/0x1160 net/ipv4/inet_connection_sock.c:1053
call_timer_fn+0x1a0/0x6b0 kernel/time/timer.c:1474
expire_timers kernel/time/timer.c:1519 [inline]
__run_timers.part.0+0x674/0xa80 kernel/time/timer.c:1790
__run_timers kernel/time/timer.c:1768 [inline]
run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1803
__do_softirq+0x1d0/0x9c8 kernel/softirq.c:571
invoke_softirq kernel/softirq.c:445 [inline]
__irq_exit_rcu+0x123/0x180 kernel/softirq.c:650
irq_exit_rcu+0x5/0x20 kernel/softirq.c:662
sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1107
</IRQ>
Fixes: d1e5e6408b30 ("tcp: Introduce optional per-netns ehash.")
Reported-by: syzbot <syzkaller@googlegroups.com>
Reported-by: Eric Dumazet <edumazet@google.com>
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20221012145036.74960-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[shaozhengchao: resolved conflicts in 5.10]
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 65acf6e0501ac8880a4f73980d01b5d27648b956 ]
In my recent commit, I missed that do_replace() handlers
use copy_from_sockptr() (which I fixed), followed
by unsafe copy_from_sockptr_offset() calls.
In all functions, we can perform the @optlen validation
before even calling xt_alloc_table_info() with the following
check:
if ((u64)optlen < (u64)tmp.size + sizeof(tmp))
return -EINVAL;
Fixes: 0c83842df40f ("netfilter: validate user input for expected length")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Pablo Neira Ayuso <pablo@netfilter.org>
Link: https://lore.kernel.org/r/20240409120741.3538135-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit cf1b7201df59fb936f40f4a807433fe3f2ce310a ]
The log_martians variable is only used in an #ifdef, causing a 'make W=1'
warning with gcc:
net/ipv4/route.c: In function 'ip_rt_send_redirect':
net/ipv4/route.c:880:13: error: variable 'log_martians' set but not used [-Werror=unused-but-set-variable]
Change the #ifdef to an equivalent IS_ENABLED() to let the compiler
see where the variable is used.
Fixes: 30038fc61adf ("net: ip_rt_send_redirect() optimization")
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240408074219.3030256-2-arnd@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3d010c8031e39f5fa1e8b13ada77e0321091011f ]
When rx-udp-gro-forwarding is enabled UDP packets might be GROed when
being forwarded. If such packets might land in a tunnel this can cause
various issues and udp_gro_receive makes sure this isn't the case by
looking for a matching socket. This is performed in
udp4/6_gro_lookup_skb but only in the current netns. This is an issue
with tunneled packets when the endpoint is in another netns. In such
cases the packets will be GROed at the UDP level, which leads to various
issues later on. The same thing can happen with rx-gro-list.
We saw this with geneve packets being GROed at the UDP level. In such
case gso_size is set; later the packet goes through the geneve rx path,
the geneve header is pulled, the offset are adjusted and frag_list skbs
are not adjusted with regard to geneve. When those skbs hit
skb_fragment, it will misbehave. Different outcomes are possible
depending on what the GROed skbs look like; from corrupted packets to
kernel crashes.
One example is a BUG_ON[1] triggered in skb_segment while processing the
frag_list. Because gso_size is wrong (geneve header was pulled)
skb_segment thinks there is "geneve header size" of data in frag_list,
although it's in fact the next packet. The BUG_ON itself has nothing to
do with the issue. This is only one of the potential issues.
Looking up for a matching socket in udp_gro_receive is fragile: the
lookup could be extended to all netns (not speaking about performances)
but nothing prevents those packets from being modified in between and we
could still not find a matching socket. It's OK to keep the current
logic there as it should cover most cases but we also need to make sure
we handle tunnel packets being GROed too early.
This is done by extending the checks in udp_unexpected_gso: GSO packets
lacking the SKB_GSO_UDP_TUNNEL/_CSUM bits and landing in a tunnel must
be segmented.
[1] kernel BUG at net/core/skbuff.c:4408!
RIP: 0010:skb_segment+0xd2a/0xf70
__udp_gso_segment+0xaa/0x560
Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.")
Fixes: 36707061d6ba ("udp: allow forwarding of plain (non-fraglisted) UDP GRO packets")
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit f0b8c30345565344df2e33a8417a27503589247d upstream.
UDP GRO validates checksums and in udp4/6_gro_complete fraglist packets
are converted to CHECKSUM_UNNECESSARY to avoid later checks. However
this is an issue for CHECKSUM_PARTIAL packets as they can be looped in
an egress path and then their partial checksums are not fixed.
Different issues can be observed, from invalid checksum on packets to
traces like:
gen01: hw csum failure
skb len=3008 headroom=160 headlen=1376 tailroom=0
mac=(106,14) net=(120,40) trans=160
shinfo(txflags=0 nr_frags=0 gso(size=0 type=0 segs=0))
csum(0xffff232e ip_summed=2 complete_sw=0 valid=0 level=0)
hash(0x77e3d716 sw=1 l4=1) proto=0x86dd pkttype=0 iif=12
...
Fix this by only converting CHECKSUM_NONE packets to
CHECKSUM_UNNECESSARY by reusing __skb_incr_checksum_unnecessary. All
other checksum types are kept as-is, including CHECKSUM_COMPLETE as
fraglist packets being segmented back would have their skb->csum valid.
Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.")
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 151c9c724d05d5b0dd8acd3e11cb69ef1f2dbada ]
We had various syzbot reports about tcp timers firing after
the corresponding netns has been dismantled.
Fortunately Josef Bacik could trigger the issue more often,
and could test a patch I wrote two years ago.
When TCP sockets are closed, we call inet_csk_clear_xmit_timers()
to 'stop' the timers.
inet_csk_clear_xmit_timers() can be called from any context,
including when socket lock is held.
This is the reason it uses sk_stop_timer(), aka del_timer().
This means that ongoing timers might finish much later.
For user sockets, this is fine because each running timer
holds a reference on the socket, and the user socket holds
a reference on the netns.
For kernel sockets, we risk that the netns is freed before
timer can complete, because kernel sockets do not hold
reference on the netns.
This patch adds inet_csk_clear_xmit_timers_sync() function
that using sk_stop_timer_sync() to make sure all timers
are terminated before the kernel socket is released.
Modules using kernel sockets close them in their netns exit()
handler.
Also add sock_not_owned_by_me() helper to get LOCKDEP
support : inet_csk_clear_xmit_timers_sync() must not be called
while socket lock is held.
It is very possible we can revert in the future commit
3a58f13a881e ("net: rds: acquire refcount on TCP sockets")
which attempted to solve the issue in rds only.
(net/smc/af_smc.c and net/mptcp/subflow.c have similar code)
We probably can remove the check_net() tests from
tcp_out_of_resources() and __tcp_close() in the future.
Reported-by: Josef Bacik <josef@toxicpanda.com>
Closes: https://lore.kernel.org/netdev/20240314210740.GA2823176@perftesting/
Fixes: 26abe14379f8 ("net: Modify sk_alloc to not reference count the netns of kernel sockets.")
Fixes: 8a68173691f0 ("net: sk_clone_lock() should only do get_net() if the parent is not a kernel socket")
Link: https://lore.kernel.org/bpf/CANn89i+484ffqb93aQm1N-tjxxvb3WDKX0EbD7318RwRgsatjw@mail.gmail.com/
Signed-off-by: Eric Dumazet <edumazet@google.com>
Tested-by: Josef Bacik <josef@toxicpanda.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Link: https://lore.kernel.org/r/20240322135732.1535772-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4bb3ba7b74fceec6f558745b25a43c6521cf5506 ]
The 'len' variable can't be negative when assigned the result of
'min_t' because all 'min_t' parameters are cast to unsigned int,
and then the minimum one is chosen.
To fix the logic, check 'len' as read from 'optlen',
where the types of relevant variables are (signed) int.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Gavrilov Ilia <Ilia.Gavrilov@infotecs.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5c3be3e0eb44b7f978bb6cbb20ad956adb93f736 ]
The 'olr' variable can't be negative when assigned the result of
'min_t' because all 'min_t' parameters are cast to unsigned int,
and then the minimum one is chosen.
To fix the logic, check 'olr' as read from 'optlen',
where the types of relevant variables are (signed) int.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Gavrilov Ilia <Ilia.Gavrilov@infotecs.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 728f064cd7ebea8c182e99e6f152c8b4a0a6b071 ]
Similar to the earlier patch that changes sk_getsockopt() to
take the sockptr_t argument. This patch also changes
do_ip_getsockopt() to take the sockptr_t argument such that
a latter patch can make bpf_getsockopt(SOL_IP) to reuse
do_ip_getsockopt().
Note on the change in ip_mc_gsfget(). This function is to
return an array of sockaddr_storage in optval. This function
is shared between ip_get_mcast_msfilter() and
compat_ip_get_mcast_msfilter(). However, the sockaddr_storage
is stored at different offset of the optval because of
the difference between group_filter and compat_group_filter.
Thus, a new 'ss_offset' argument is added to ip_mc_gsfget().
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20220902002828.2890585-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Stable-dep-of: 5c3be3e0eb44 ("ipmr: fix incorrect parameter validation in the ip_mroute_getsockopt() function")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4167a960574fcadc9067f4280951a35b8c021c68 ]
Revert the use of structr_size() and stay with IP_MSFILTER_SIZE() for
now, as in this case, the size of struct ip_msfilter didn't change with
the addition of the flexible array imsf_slist_flex[]. So, if we use
struct_size() we will be allocating and calculating the size of
struct ip_msfilter with one too many items for imsf_slist_flex[].
We might use struct_size() in the future, but for now let's stay
with IP_MSFILTER_SIZE().
Fixes: 2d3e5caf96b9 ("net/ipv4: Replace one-element array with flexible-array member")
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 5c3be3e0eb44 ("ipmr: fix incorrect parameter validation in the ip_mroute_getsockopt() function")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2d3e5caf96b9449af951e63476657acd759c1a30 ]
There is a regular need in the kernel to provide a way to declare having
a dynamically sized set of trailing elements in a structure. Kernel code
should always use “flexible array members”[1] for these cases. The older
style of one-element or zero-length arrays should no longer be used[2].
Use an anonymous union with a couple of anonymous structs in order to
keep userspace unchanged:
$ pahole -C ip_msfilter net/ipv4/ip_sockglue.o
struct ip_msfilter {
union {
struct {
__be32 imsf_multiaddr_aux; /* 0 4 */
__be32 imsf_interface_aux; /* 4 4 */
__u32 imsf_fmode_aux; /* 8 4 */
__u32 imsf_numsrc_aux; /* 12 4 */
__be32 imsf_slist[1]; /* 16 4 */
}; /* 0 20 */
struct {
__be32 imsf_multiaddr; /* 0 4 */
__be32 imsf_interface; /* 4 4 */
__u32 imsf_fmode; /* 8 4 */
__u32 imsf_numsrc; /* 12 4 */
__be32 imsf_slist_flex[0]; /* 16 0 */
}; /* 0 16 */
}; /* 0 20 */
/* size: 20, cachelines: 1, members: 1 */
/* last cacheline: 20 bytes */
};
Also, refactor the code accordingly and make use of the struct_size()
and flex_array_size() helpers.
This helps with the ongoing efforts to globally enable -Warray-bounds
and get us closer to being able to tighten the FORTIFY_SOURCE routines
on memcpy().
[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.10/process/deprecated.html#zero-length-and-one-element-arrays
Link: https://github.com/KSPP/linux/issues/79
Link: https://github.com/KSPP/linux/issues/109
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 5c3be3e0eb44 ("ipmr: fix incorrect parameter validation in the ip_mroute_getsockopt() function")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 716edc9706deb3bb2ff56e2eeb83559cea8f22db ]
The 'len' variable can't be negative when assigned the result of
'min_t' because all 'min_t' parameters are cast to unsigned int,
and then the minimum one is chosen.
To fix the logic, check 'len' as read from 'optlen',
where the types of relevant variables are (signed) int.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Gavrilov Ilia <Ilia.Gavrilov@infotecs.ru>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5ae1e9922bbdbaeb9cfbe91085ab75927488ac0f ]
syzkaller triggered following kasan splat:
BUG: KASAN: use-after-free in __skb_flow_dissect+0x19d1/0x7a50 net/core/flow_dissector.c:1170
Read of size 1 at addr ffff88812fb4000e by task syz-executor183/5191
[..]
kasan_report+0xda/0x110 mm/kasan/report.c:588
__skb_flow_dissect+0x19d1/0x7a50 net/core/flow_dissector.c:1170
skb_flow_dissect_flow_keys include/linux/skbuff.h:1514 [inline]
___skb_get_hash net/core/flow_dissector.c:1791 [inline]
__skb_get_hash+0xc7/0x540 net/core/flow_dissector.c:1856
skb_get_hash include/linux/skbuff.h:1556 [inline]
ip_tunnel_xmit+0x1855/0x33c0 net/ipv4/ip_tunnel.c:748
ipip_tunnel_xmit+0x3cc/0x4e0 net/ipv4/ipip.c:308
__netdev_start_xmit include/linux/netdevice.h:4940 [inline]
netdev_start_xmit include/linux/netdevice.h:4954 [inline]
xmit_one net/core/dev.c:3548 [inline]
dev_hard_start_xmit+0x13d/0x6d0 net/core/dev.c:3564
__dev_queue_xmit+0x7c1/0x3d60 net/core/dev.c:4349
dev_queue_xmit include/linux/netdevice.h:3134 [inline]
neigh_connected_output+0x42c/0x5d0 net/core/neighbour.c:1592
...
ip_finish_output2+0x833/0x2550 net/ipv4/ip_output.c:235
ip_finish_output+0x31/0x310 net/ipv4/ip_output.c:323
..
iptunnel_xmit+0x5b4/0x9b0 net/ipv4/ip_tunnel_core.c:82
ip_tunnel_xmit+0x1dbc/0x33c0 net/ipv4/ip_tunnel.c:831
ipgre_xmit+0x4a1/0x980 net/ipv4/ip_gre.c:665
__netdev_start_xmit include/linux/netdevice.h:4940 [inline]
netdev_start_xmit include/linux/netdevice.h:4954 [inline]
xmit_one net/core/dev.c:3548 [inline]
dev_hard_start_xmit+0x13d/0x6d0 net/core/dev.c:3564
...
The splat occurs because skb->data points past skb->head allocated area.
This is because neigh layer does:
__skb_pull(skb, skb_network_offset(skb));
... but skb_network_offset() returns a negative offset and __skb_pull()
arg is unsigned. IOW, we skb->data gets "adjusted" by a huge value.
The negative value is returned because skb->head and skb->data distance is
more than 64k and skb->network_header (u16) has wrapped around.
The bug is in the ip_tunnel infrastructure, which can cause
dev->needed_headroom to increment ad infinitum.
The syzkaller reproducer consists of packets getting routed via a gre
tunnel, and route of gre encapsulated packets pointing at another (ipip)
tunnel. The ipip encapsulation finds gre0 as next output device.
This results in the following pattern:
1). First packet is to be sent out via gre0.
Route lookup found an output device, ipip0.
2).
ip_tunnel_xmit for gre0 bumps gre0->needed_headroom based on the future
output device, rt.dev->needed_headroom (ipip0).
3).
ip output / start_xmit moves skb on to ipip0. which runs the same
code path again (xmit recursion).
4).
Routing step for the post-gre0-encap packet finds gre0 as output device
to use for ipip0 encapsulated packet.
tunl0->needed_headroom is then incremented based on the (already bumped)
gre0 device headroom.
This repeats for every future packet:
gre0->needed_headroom gets inflated because previous packets' ipip0 step
incremented rt->dev (gre0) headroom, and ipip0 incremented because gre0
needed_headroom was increased.
For each subsequent packet, gre/ipip0->needed_headroom grows until
post-expand-head reallocations result in a skb->head/data distance of
more than 64k.
Once that happens, skb->network_header (u16) wraps around when
pskb_expand_head tries to make sure that skb_network_offset() is unchanged
after the headroom expansion/reallocation.
After this skb_network_offset(skb) returns a different (and negative)
result post headroom expansion.
The next trip to neigh layer (or anything else that would __skb_pull the
network header) makes skb->data point to a memory location outside
skb->head area.
v2: Cap the needed_headroom update to an arbitarily chosen upperlimit to
prevent perpetual increase instead of dropping the headroom increment
completely.
Reported-and-tested-by: syzbot+bfde3bef047a81b8fde6@syzkaller.appspotmail.com
Closes: https://groups.google.com/g/syzkaller-bugs/c/fL9G6GtWskY/m/VKk_PR5FBAAJ
Fixes: 243aad830e8a ("ip_gre: include route header_len in max_headroom calculation")
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20240220135606.4939-1-fw@strlen.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Ido Schimmel