syzbot


divide error in mac80211_hwsim_bss_info_changed (4)

Status: upstream: reported on 2026/07/17 11:17
Reported-by: syzbot+3217247356ff032ef556@syzkaller.appspotmail.com
First crash: 6d00h, last: 6d00h
Similar bugs (8)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 divide error in mac80211_hwsim_bss_info_changed 2 3 650d 741d 0/3 auto-obsoleted due to no activity on 2025/01/18 21:46
android-54 divide error in mac80211_hwsim_bss_info_changed 2 2 2109d 2116d 0/2 auto-closed as invalid on 2021/02/09 23:56
linux-5.15 divide error in mac80211_hwsim_bss_info_changed (2) 2 4 275d 399d 0/3 auto-obsoleted due to no activity on 2026/01/28 19:16
linux-5.15 divide error in mac80211_hwsim_bss_info_changed (3) 2 1 123d 123d 0/3 auto-obsoleted due to no activity on 2026/06/29 21:56
upstream divide error in mac80211_hwsim_bss_info_changed (2) wireless 2 2 1690d 1738d 0/29 auto-closed as invalid on 2022/04/04 22:30
linux-4.19 divide error in mac80211_hwsim_bss_info_changed (2) 2 1 1242d 1242d 0/1 upstream: reported on 2023/02/27 09:41
upstream divide error in mac80211_hwsim_bss_info_changed wireless 2 1 1926d 1893d 0/29 auto-closed as invalid on 2021/08/12 01:33
linux-4.19 divide error in mac80211_hwsim_bss_info_changed 2 1 1372d 1372d 0/1 auto-obsoleted due to no activity on 2023/02/16 17:15

Sample crash report:
divide error: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 4426 Comm: kworker/u4:13 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026
Workqueue: phy15 ieee80211_roc_work
RIP: 0010:mac80211_hwsim_bss_info_changed+0x3ed/0xea0 drivers/net/wireless/mac80211_hwsim.c:2037
Code: 40 3d 00 00 4c 03 2b 48 b8 00 00 00 00 00 fc ff df 41 80 3c 04 00 74 08 4c 89 f7 e8 ad f1 05 fc 49 8b 0e 89 ce 4c 89 e8 31 d2 <48> f7 f6 29 d1 48 69 f1 e8 03 00 00 48 8b 7c 24 18 31 d2 b9 05 00
RSP: 0018:ffffc900031afa80 EFLAGS: 00010246
RAX: 000656ccb1f83deb RBX: ffff8880704ff180 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000040
RBP: ffffc900031afb48 R08: ffffffff901e912f R09: 1ffffffff203d225
R10: dffffc0000000000 R11: fffffbfff203d226 R12: 1ffff1100e09fe04
R13: 000656ccb1f83deb R14: ffff8880704ff020 R15: 0000000000000200
FS:  0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005582a7609f28 CR3: 0000000061d5f000 CR4: 00000000003506e0
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+0x312/0x450 net/mac80211/offchannel.c:158
 __ieee80211_roc_work+0x1f3/0x2b0 net/mac80211/offchannel.c:444
 ieee80211_roc_work+0x2b/0x40 net/mac80211/offchannel.c:458
 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 f68b1455c6ac3a3f ]---
RIP: 0010:mac80211_hwsim_bss_info_changed+0x3ed/0xea0 drivers/net/wireless/mac80211_hwsim.c:2037
Code: 40 3d 00 00 4c 03 2b 48 b8 00 00 00 00 00 fc ff df 41 80 3c 04 00 74 08 4c 89 f7 e8 ad f1 05 fc 49 8b 0e 89 ce 4c 89 e8 31 d2 <48> f7 f6 29 d1 48 69 f1 e8 03 00 00 48 8b 7c 24 18 31 d2 b9 05 00
RSP: 0018:ffffc900031afa80 EFLAGS: 00010246
RAX: 000656ccb1f83deb RBX: ffff8880704ff180 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000040
RBP: ffffc900031afb48 R08: ffffffff901e912f R09: 1ffffffff203d225
R10: dffffc0000000000 R11: fffffbfff203d226 R12: 1ffff1100e09fe04
R13: 000656ccb1f83deb R14: ffff8880704ff020 R15: 0000000000000200
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005577cd4a6000 CR3: 000000002b589000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	40 3d 00 00 4c 03    	rex cmp $0x34c0000,%eax
   6:	2b 48 b8             	sub    -0x48(%rax),%ecx
   9:	00 00                	add    %al,(%rax)
   b:	00 00                	add    %al,(%rax)
   d:	00 fc                	add    %bh,%ah
   f:	ff                   	lcall  (bad)
  10:	df 41 80             	filds  -0x80(%rcx)
  13:	3c 04                	cmp    $0x4,%al
  15:	00 74 08 4c          	add    %dh,0x4c(%rax,%rcx,1)
  19:	89 f7                	mov    %esi,%edi
  1b:	e8 ad f1 05 fc       	call   0xfc05f1cd
  20:	49 8b 0e             	mov    (%r14),%rcx
  23:	89 ce                	mov    %ecx,%esi
  25:	4c 89 e8             	mov    %r13,%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:	48 8b 7c 24 18       	mov    0x18(%rsp),%rdi
  3b:	31 d2                	xor    %edx,%edx
  3d:	b9                   	.byte 0xb9
  3e:	05                   	.byte 0x5

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/17 11:17 linux-5.15.y c86c4726e7f0 7f27c57a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan divide error in mac80211_hwsim_bss_info_changed
* Struck through repros no longer work on HEAD.