[syzbot ci] Re: af_unix: fix u->inq_len accounting in manage_oob() and unix_stream_read_skb()

From: syzbot ci

Date: Tue Sep 22 2026 - 00:46:21 EST


syzbot ci has tested the following series

[v1] af_unix: fix u->inq_len accounting in manage_oob() and unix_stream_read_skb()
https://lore.kernel.org/all/20260919221735.3708237-1-benquike@xxxxxxxxx
* [PATCH] af_unix: fix u->inq_len accounting in manage_oob() and unix_stream_read_skb()

and found the following issue:
kernel BUG in unix_stream_read_skb

Full report is available here:
https://ci.syzbot.org/series/0ffad94e-8c51-41d9-b85f-9793ff3deaf5

***

kernel BUG in unix_stream_read_skb

tree: net-next
URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/netdev/net-next.git
base: b5a051f6b840d48f159166ef073d3021989bfb50
arch: amd64
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
config: https://ci.syzbot.org/builds/127895ae-9f2e-46db-a972-bc6f975448e6/config

skb linear: 00000100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
skb linear: 00000110: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
skb linear: 00000120: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
------------[ cut here ]------------
kernel BUG at ./include/linux/skbuff.h:2847!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 1 UID: 0 PID: 16941 Comm: syz.0.3527 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:skb_pull+0x1c4/0x1d0
Code: b2 8c f8 8b 44 24 04 89 43 70 48 c7 c7 c0 ba 22 8d 89 ee e8 9e 96 7c f7 48 c7 c7 00 bb 22 8d 48 89 de 31 d2 e8 7d 00 ff ff 90 <0f> 0b 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc9000629f758 EFLAGS: 00010282
RAX: ffffffff89aa3aaa RBX: ffff888107756780 RCX: 0000000000080000
RDX: ffffc90021fe7000 RSI: 000000000000b6ec RDI: 000000000000b6ed
RBP: 0000000000001000 R08: ffff88823c624713 R09: 1ffff110478c48e2
R10: dffffc0000000000 R11: ffffed10478c48e3 R12: 0000000000008000
R13: dffffc0000000000 R14: 1ffff11020eeacfe R15: 0000000000007ec0
FS: 00007f4d8a7ef6c0(0000) GS:ffff8882a8cce000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000c4000 CR3: 000000002253a000 CR4: 00000000000006f0
Call Trace:
<TASK>
unix_stream_read_skb+0x34a/0x500
sk_psock_verdict_data_ready+0x25f/0x690
unix_stream_sendmsg+0x84e/0xde0
sock_sendmsg_nosec+0x13a/0x180
____sys_sendmsg+0x54e/0x850
___sys_sendmsg+0x2a5/0x360
__x64_sys_sendmsg+0x1b1/0x290
do_syscall_64+0x166/0x520
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4d8999e159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f4d8a7ef028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f4d89c26180 RCX: 00007f4d8999e159
RDX: 0000000000000000 RSI: 0000200000000500 RDI: 0000000000000005
RBP: 00007f4d89a3506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4d89c26218 R14: 00007f4d89c26180 R15: 00007ffd1de3bf98
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:skb_pull+0x1c4/0x1d0
Code: b2 8c f8 8b 44 24 04 89 43 70 48 c7 c7 c0 ba 22 8d 89 ee e8 9e 96 7c f7 48 c7 c7 00 bb 22 8d 48 89 de 31 d2 e8 7d 00 ff ff 90 <0f> 0b 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc9000629f758 EFLAGS: 00010282
RAX: ffffffff89aa3aaa RBX: ffff888107756780 RCX: 0000000000080000
RDX: ffffc90021fe7000 RSI: 000000000000b6ec RDI: 000000000000b6ed
RBP: 0000000000001000 R08: ffff88823c624713 R09: 1ffff110478c48e2
R10: dffffc0000000000 R11: ffffed10478c48e3 R12: 0000000000008000
R13: dffffc0000000000 R14: 1ffff11020eeacfe R15: 0000000000007ec0
FS: 00007f4d8a7ef6c0(0000) GS:ffff88818d6ce000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fda6ffeb840 CR3: 000000002253a000 CR4: 00000000000006f0


***

If these findings have caused you to resend the series or submit a
separate fix, please add the following tag to your commit message:
Tested-by: syzbot@xxxxxxxxxxxxxxxxxxxxxxxxx

---
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