AI Score
Confidence
Low
EPSS
Percentile
13.5%
SSVC
Exploitation
none
Automatable
no
Technical Impact
partial
In the Linux kernel, the following vulnerability has been resolved:
net: relax socket state check at accept time.
Christoph reported the following splat:
WARNING: CPU: 1 PID: 772 at net/ipv4/af_inet.c:761 __inet_accept+0x1f4/0x4a0
Modules linked in:
CPU: 1 PID: 772 Comm: syz-executor510 Not tainted 6.9.0-rc7-g7da7119fe22b #56
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014
RIP: 0010:__inet_accept+0x1f4/0x4a0 net/ipv4/af_inet.c:759
Code: 04 38 84 c0 0f 85 87 00 00 00 41 c7 04 24 03 00 00 00 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc e8 ec b7 da fd <0f> 0b e9 7f fe ff ff e8 e0 b7 da fd 0f 0b e9 fe fe ff ff 89 d9 80
RSP: 0018:ffffc90000c2fc58 EFLAGS: 00010293
RAX: ffffffff836bdd14 RBX: 0000000000000000 RCX: ffff888104668000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: dffffc0000000000 R08: ffffffff836bdb89 R09: fffff52000185f64
R10: dffffc0000000000 R11: fffff52000185f64 R12: dffffc0000000000
R13: 1ffff92000185f98 R14: ffff88810754d880 R15: ffff8881007b7800
FS: 000000001c772880(0000) GS:ffff88811b280000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb9fcf2e178 CR3: 00000001045d2002 CR4: 0000000000770ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
<TASK>
inet_accept+0x138/0x1d0 net/ipv4/af_inet.c:786
do_accept+0x435/0x620 net/socket.c:1929
__sys_accept4_file net/socket.c:1969 [inline]
__sys_accept4+0x9b/0x110 net/socket.c:1999
__do_sys_accept net/socket.c:2016 [inline]
__se_sys_accept net/socket.c:2013 [inline]
__x64_sys_accept+0x7d/0x90 net/socket.c:2013
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x58/0x100 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x4315f9
Code: fd ff 48 81 c4 80 00 00 00 e9 f1 fe ff ff 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 ab b4 fd ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffdb26d9c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002b
RAX: ffffffffffffffda RBX: 0000000000400300 RCX: 00000000004315f9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00000000006e1018 R08: 0000000000400300 R09: 0000000000400300
R10: 0000000000400300 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000040cdf0 R14: 000000000040ce80 R15: 0000000000000055
</TASK>
The reproducer invokes shutdown() before entering the listener status.
After commit 94062790aedb (“tcp: defer shutdown(SEND_SHUTDOWN) for
TCP_SYN_RECV sockets”), the above causes the child to reach the accept
syscall in FIN_WAIT1 status.
Eric noted we can relax the existing assertion in __inet_accept()
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "34e41a031fd7",
"lessThan": "7de00adc9bd0",
"versionType": "git"
},
{
"status": "affected",
"version": "ed5e279b69e0",
"lessThan": "59801e88c99f",
"versionType": "git"
},
{
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"versionType": "git"
},
{
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"version": "2552c9d9440f",
"lessThan": "21c14c556ccc",
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{
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{
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{
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},
{
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"version": "94062790aedb",
"lessThan": "26afda78cda3",
"versionType": "git"
}
],
"programFiles": [
"net/ipv4/af_inet.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.9"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.9",
"versionType": "custom"
},
{
"status": "unaffected",
"version": "4.19.319",
"versionType": "custom",
"lessThanOrEqual": "4.19.*"
},
{
"status": "unaffected",
"version": "5.4.281",
"versionType": "custom",
"lessThanOrEqual": "5.4.*"
},
{
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"version": "5.10.223",
"versionType": "custom",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.164",
"versionType": "custom",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.93",
"versionType": "custom",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.33",
"versionType": "custom",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.9.4",
"versionType": "custom",
"lessThanOrEqual": "6.9.*"
},
{
"status": "unaffected",
"version": "6.10",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/ipv4/af_inet.c"
],
"defaultStatus": "affected"
}
]
git.kernel.org/stable/c/21c14c556cccd0cb54b71ec5e901e64ba84c7165
git.kernel.org/stable/c/26afda78cda3da974fd4c287962c169e9462c495
git.kernel.org/stable/c/59801e88c99f7c3f44a4d20af6ba6417aa359b5d
git.kernel.org/stable/c/5f9a04a94fd1894d7009055ab8e5832a0242dba3
git.kernel.org/stable/c/6e03006548c66b979f4e5e9fc797aac4dad82822
git.kernel.org/stable/c/7de00adc9bd035d861ba4177848ca0bfa5ed1e04
git.kernel.org/stable/c/87bdc9f6f58b4417362d6932b49b828e319f97dc
git.kernel.org/stable/c/c09ddc605893df542c6cf8dde6a57a93f7cf0adb