[moderation] [bluetooth?] general protection fault in hci_abort_conn (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 4c87cdd03284 Add linux-next specific files for 20260130
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1435c802580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f48a8f563da78a70
dashboard link: https://syzkaller.appspot.com/bug?extid=1fb6141b2bf3022dc758
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8
CC: [johan....@gmail.com linux-b...@vger.kernel.org linux-...@vger.kernel.org luiz....@gmail.com mar...@holtmann.org]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/255199c1284a/disk-4c87cdd0.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/7dcd34a86ba2/vmlinux-4c87cdd0.xz
kernel image: https://storage.googleapis.com/syzbot-assets/49cfce49a660/bzImage-4c87cdd0.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+1fb614...@syzkaller.appspotmail.com

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000007: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f]
CPU: 0 UID: 0 PID: 5827 Comm: kworker/u9:2 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Workqueue: hci5 hci_conn_timeout
RIP: 0010:hci_abort_conn+0x143/0x360 net/bluetooth/hci_conn.c:3099
Code: bc 24 48 0e 00 00 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 2b 62 97 f7 4d 8b 3f 49 83 c7 3b 4c 89 f8 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 29 01 00 00 45 0f b6 3f 4c 89 ff 48 c7
RSP: 0018:ffffc9000424faf8 EFLAGS: 00010202
RAX: 0000000000000007 RBX: ffff888022f34000 RCX: 0000000000000000
RDX: ffff88807d4c5ac0 RSI: 0000000000000001 RDI: 0000000000000001
RBP: 0000000000000001 R08: ffff88807d4c5ac0 R09: 0000000000000002
R10: 0000000000000080 R11: 0000000000000000 R12: ffff888051adc000
R13: dffffc0000000000 R14: ffff888022f3495c R15: 000000000000003b
FS: 0000000000000000(0000) GS:ffff888125296000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3563be8600 CR3: 0000000044bd6000 CR4: 00000000003526f0
Call Trace:
<TASK>
process_one_work+0x949/0x15a0 kernel/workqueue.c:3279
process_scheduled_works kernel/workqueue.c:3362 [inline]
worker_thread+0xb46/0x1140 kernel/workqueue.c:3443
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:hci_abort_conn+0x143/0x360 net/bluetooth/hci_conn.c:3099
Code: bc 24 48 0e 00 00 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 ff e8 2b 62 97 f7 4d 8b 3f 49 83 c7 3b 4c 89 f8 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 29 01 00 00 45 0f b6 3f 4c 89 ff 48 c7
RSP: 0018:ffffc9000424faf8 EFLAGS: 00010202
RAX: 0000000000000007 RBX: ffff888022f34000 RCX: 0000000000000000
RDX: ffff88807d4c5ac0 RSI: 0000000000000001 RDI: 0000000000000001
RBP: 0000000000000001 R08: ffff88807d4c5ac0 R09: 0000000000000002
R10: 0000000000000080 R11: 0000000000000000 R12: ffff888051adc000
R13: dffffc0000000000 R14: ffff888022f3495c R15: 000000000000003b
FS: 0000000000000000(0000) GS:ffff888125396000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30b11ff8 CR3: 000000000e54c000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
0: bc 24 48 0e 00 mov $0xe4824,%esp
5: 00 4c 89 f8 add %cl,-0x8(%rcx,%rcx,4)
9: 48 c1 e8 03 shr $0x3,%rax
d: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1)
12: 74 08 je 0x1c
14: 4c 89 ff mov %r15,%rdi
17: e8 2b 62 97 f7 call 0xf7976247
1c: 4d 8b 3f mov (%r15),%r15
1f: 49 83 c7 3b add $0x3b,%r15
23: 4c 89 f8 mov %r15,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 0f b6 04 28 movzbl (%rax,%r13,1),%eax <-- trapping instruction
2f: 84 c0 test %al,%al
31: 0f 85 29 01 00 00 jne 0x160
37: 45 0f b6 3f movzbl (%r15),%r15d
3b: 4c 89 ff mov %r15,%rdi
3e: 48 rex.W
3f: c7 .byte 0xc7


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