[v5.15] divide error in mac80211_hwsim_bss_info_changed (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 91d48252ad4b Linux 5.15.202
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16f566da580000
kernel config: https://syzkaller.appspot.com/x/.config?x=353ae28c40b35af5
dashboard link: https://syzkaller.appspot.com/bug?extid=fce67fee1c1489156498
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/74e75dfcb812/disk-91d48252.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/bfa72aab00f2/vmlinux-91d48252.xz
kernel image: https://storage.googleapis.com/syzbot-assets/47ea72d1c7dc/bzImage-91d48252.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+fce67f...@syzkaller.appspotmail.com

divide error: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 4349 Comm: kworker/u4:19 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: phy13 ieee80211_roc_work
RIP: 0010:mac80211_hwsim_bss_info_changed+0x3d6/0xeb0 drivers/net/wireless/mac80211_hwsim.c:2037
Code: 00 4d 03 34 24 42 80 3c 2b 00 4c 8b 64 24 18 74 0e 48 89 fb 4c 89 e7 e8 a8 ac 09 fc 48 89 df 49 8b 0c 24 89 ce 4c 89 f0 31 d2 <48> f7 f6 29 d1 48 69 f1 e8 03 00 00 31 d2 b9 05 00 00 00 e8 92 2a
RSP: 0018:ffffc9000325fa80 EFLAGS: 00010246
RAX: 00064d8fdd9ac03f RBX: 1ffff1100567ee0c RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88802b3f7100
RBP: ffffc9000325fb48 R08: ffffffff901d412f R09: 1ffffffff203a825
R10: dffffc0000000000 R11: fffffbfff203a826 R12: ffff88802b3f7060
R13: dffffc0000000000 R14: 00064d8fdd9ac03f R15: 0000000000000200
FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb5034cf660 CR3: 00000000630b0000 CR4: 00000000003526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
drv_bss_info_changed net/mac80211/driver-ops.h:177 [inline]
ieee80211_bss_info_change_notify+0x307/0x550 net/mac80211/main.c:212
ieee80211_offchannel_return+0x314/0x450 net/mac80211/offchannel.c:158
__ieee80211_roc_work+0x1f9/0x2b0 net/mac80211/offchannel.c:444
ieee80211_roc_work+0x2b/0x40 net/mac80211/offchannel.c:458
process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
</TASK>
Modules linked in:
---[ end trace 645d655e10ccceaf ]---
RIP: 0010:mac80211_hwsim_bss_info_changed+0x3d6/0xeb0 drivers/net/wireless/mac80211_hwsim.c:2037
Code: 00 4d 03 34 24 42 80 3c 2b 00 4c 8b 64 24 18 74 0e 48 89 fb 4c 89 e7 e8 a8 ac 09 fc 48 89 df 49 8b 0c 24 89 ce 4c 89 f0 31 d2 <48> f7 f6 29 d1 48 69 f1 e8 03 00 00 31 d2 b9 05 00 00 00 e8 92 2a
RSP: 0018:ffffc9000325fa80 EFLAGS: 00010246
RAX: 00064d8fdd9ac03f RBX: 1ffff1100567ee0c RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88802b3f7100
RBP: ffffc9000325fb48 R08: ffffffff901d412f R09: 1ffffffff203a825
R10: dffffc0000000000 R11: fffffbfff203a826 R12: ffff88802b3f7060
R13: dffffc0000000000 R14: 00064d8fdd9ac03f R15: 0000000000000200
FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31413ff8 CR3: 0000000022f4b000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 00 4d 03 add %cl,0x3(%rbp)
3: 34 24 xor $0x24,%al
5: 42 80 3c 2b 00 cmpb $0x0,(%rbx,%r13,1)
a: 4c 8b 64 24 18 mov 0x18(%rsp),%r12
f: 74 0e je 0x1f
11: 48 89 fb mov %rdi,%rbx
14: 4c 89 e7 mov %r12,%rdi
17: e8 a8 ac 09 fc call 0xfc09acc4
1c: 48 89 df mov %rbx,%rdi
1f: 49 8b 0c 24 mov (%r12),%rcx
23: 89 ce mov %ecx,%esi
25: 4c 89 f0 mov %r14,%rax
28: 31 d2 xor %edx,%edx
* 2a: 48 f7 f6 div %rsi <-- trapping instruction
2d: 29 d1 sub %edx,%ecx
2f: 48 69 f1 e8 03 00 00 imul $0x3e8,%rcx,%rsi
36: 31 d2 xor %edx,%edx
38: b9 05 00 00 00 mov $0x5,%ecx
3d: e8 .byte 0xe8
3e: 92 xchg %eax,%edx
3f: 2a .byte 0x2a


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