[v5.15] general protection fault in rxrpc_kernel_abort_call

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: aabd761612db Linux 5.15.215
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=13531a25580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f161cbc9aef65db0
dashboard link: https://syzkaller.appspot.com/bug?extid=2ee4b39c54a8433b3579
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/f636f56d3662/disk-aabd7616.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/f1a46620f40c/vmlinux-aabd7616.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9b78bb48b022/bzImage-aabd7616.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+2ee4b3...@syzkaller.appspotmail.com

general protection fault, probably for non-canonical address 0xdffffc0000000013: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000098-0x000000000000009f]
CPU: 1 PID: 4176 Comm: kworker/1:3 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: kafsd afs_process_async_call
RIP: 0010:__mutex_lock_common+0x10c/0x2400 kernel/locking/mutex.c:575
Code: 03 42 0f b6 04 28 84 c0 0f 85 50 1c 00 00 4c 8d b4 24 e0 00 00 00 83 3d a1 c3 66 0c 00 75 29 48 8d 7b 60 48 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 05 e8 78 93 f5 f7 48 39 5b 60 4c 8d b4 24 e0 00
RSP: 0018:ffffc90002d8f940 EFLAGS: 00010202
RAX: 0000000000000013 RBX: 0000000000000038 RCX: ffffffff962f4f03
RDX: ffff8880721bbb80 RSI: ffffffff8a2b3e80 RDI: 0000000000000098
RBP: ffffc90002d8fad0 R08: ffffffff890732d6 R09: 0000000000000000
R10: 00000000fffffffb R11: 0000000000000000 R12: 0000000000000000
R13: dffffc0000000000 R14: ffffc90002d8fa20 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbc111f0000 CR3: 0000000060692000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__mutex_lock kernel/locking/mutex.c:729 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
rxrpc_kernel_abort_call+0x26/0x70 net/rxrpc/sendmsg.c:853
afs_deliver_to_call+0x55e/0x1100 fs/afs/rxrpc.c:-1
afs_process_async_call+0x7e/0xe0 fs/afs/rxrpc.c:702
process_one_work+0x867/0xff0 kernel/workqueue.c:2310
worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
kthread+0x42e/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
Modules linked in:
---[ end trace 0c8036716a780de6 ]---
RIP: 0010:__mutex_lock_common+0x10c/0x2400 kernel/locking/mutex.c:575
Code: 03 42 0f b6 04 28 84 c0 0f 85 50 1c 00 00 4c 8d b4 24 e0 00 00 00 83 3d a1 c3 66 0c 00 75 29 48 8d 7b 60 48 89 f8 48 c1 e8 03 <42> 80 3c 28 00 74 05 e8 78 93 f5 f7 48 39 5b 60 4c 8d b4 24 e0 00
RSP: 0018:ffffc90002d8f940 EFLAGS: 00010202
RAX: 0000000000000013 RBX: 0000000000000038 RCX: ffffffff962f4f03
RDX: ffff8880721bbb80 RSI: ffffffff8a2b3e80 RDI: 0000000000000098
RBP: ffffc90002d8fad0 R08: ffffffff890732d6 R09: 0000000000000000
R10: 00000000fffffffb R11: 0000000000000000 R12: 0000000000000000
R13: dffffc0000000000 R14: ffffc90002d8fa20 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdb7b308000 CR3: 000000005fbe5000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 03 42 0f add 0xf(%rdx),%eax
3: b6 04 mov $0x4,%dh
5: 28 84 c0 0f 85 50 1c sub %al,0x1c50850f(%rax,%rax,8)
c: 00 00 add %al,(%rax)
e: 4c 8d b4 24 e0 00 00 lea 0xe0(%rsp),%r14
15: 00
16: 83 3d a1 c3 66 0c 00 cmpl $0x0,0xc66c3a1(%rip) # 0xc66c3be
1d: 75 29 jne 0x48
1f: 48 8d 7b 60 lea 0x60(%rbx),%rdi
23: 48 89 f8 mov %rdi,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1) <-- trapping instruction
2f: 74 05 je 0x36
31: e8 78 93 f5 f7 call 0xf7f593ae
36: 48 39 5b 60 cmp %rbx,0x60(%rbx)
3a: 4c rex.WR
3b: 8d .byte 0x8d
3c: b4 24 mov $0x24,%ah
3e: e0 00 loopne 0x40


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup