CVE-2024-36484 Information
Description
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:
The reproducer invokes shutdown() before entering the listener status. After commit 94062790aedb ( cp: 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()
Reference
https://git.kernel.org/stable/c/c09ddc605893df542c6cf8dde6a57a93f7cf0adb https://git.kernel.org/stable/c/87bdc9f6f58b4417362d6932b49b828e319f97dc https://git.kernel.org/stable/c/5f9a04a94fd1894d7009055ab8e5832a0242dba3 https://git.kernel.org/stable/c/26afda78cda3da974fd4c287962c169e9462c495
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