syzbot


divide error in mac80211_hwsim_bss_info_changed (2)

Status: auto-closed as invalid on 2022/04/04 22:30
Reported-by: syzbot+5f110beab9fb01e48be5@syzkaller.appspotmail.com
First crash: 344d, last: 294d
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-54 divide error in mac80211_hwsim_bss_info_changed 2 713d 720d 0/2 auto-closed as invalid on 2021/02/09 23:56
upstream divide error in mac80211_hwsim_bss_info_changed 1 530d 496d 0/24 auto-closed as invalid on 2021/08/12 01:33

Sample crash report:
divide error: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 1106 Comm: kworker/u4:6 Not tainted 5.16.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: phy13 ieee80211_roc_work
RIP: 0010:mac80211_hwsim_bss_info_changed+0xd2e/0xf00 drivers/net/wireless/mac80211_hwsim.c:2033
Code: 48 ba 00 00 00 00 00 fc ff df 48 c1 e9 03 80 3c 11 00 0f 85 96 01 00 00 49 8b b6 08 3d 00 00 49 8d be a8 3d 00 00 31 d2 89 f1 <48> f7 f1 29 d6 b9 05 00 00 00 31 d2 48 69 f6 e8 03 00 00 e8 2a 39
RSP: 0018:ffffc90004e6fb70 EFLAGS: 00010246
RAX: 0005d26dae2f59da RBX: 0000000000000200 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88802ac67088
RBP: ffff88802b012078 R08: 000000000000b514 R09: ffffffff8ff76a67
R10: ffffffff8166e65f R11: 0000000000000000 R12: ffff88802ac60da0
R13: ffff88802ac66fe8 R14: ffff88802ac632e0 R15: ffff88802ac632e0
FS:  0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc8482f8058 CR3: 0000000077745000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 drv_bss_info_changed+0x2c4/0x5f0 net/mac80211/driver-ops.h:177
 ieee80211_bss_info_change_notify+0x9a/0xc0 net/mac80211/main.c:210
 ieee80211_offchannel_return+0x330/0x4a0 net/mac80211/offchannel.c:158
 __ieee80211_roc_work+0x35a/0x3d0 net/mac80211/offchannel.c:444
 ieee80211_roc_work+0x2b/0x40 net/mac80211/offchannel.c:458
 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298
 worker_thread+0x658/0x11f0 kernel/workqueue.c:2445
 kthread+0x405/0x4f0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Modules linked in:
---[ end trace 65ee6fd116bf1027 ]---
RIP: 0010:mac80211_hwsim_bss_info_changed+0xd2e/0xf00 drivers/net/wireless/mac80211_hwsim.c:2033
Code: 48 ba 00 00 00 00 00 fc ff df 48 c1 e9 03 80 3c 11 00 0f 85 96 01 00 00 49 8b b6 08 3d 00 00 49 8d be a8 3d 00 00 31 d2 89 f1 <48> f7 f1 29 d6 b9 05 00 00 00 31 d2 48 69 f6 e8 03 00 00 e8 2a 39
RSP: 0018:ffffc90004e6fb70 EFLAGS: 00010246
RAX: 0005d26dae2f59da RBX: 0000000000000200 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88802ac67088
RBP: ffff88802b012078 R08: 000000000000b514 R09: ffffffff8ff76a67
R10: ffffffff8166e65f R11: 0000000000000000 R12: ffff88802ac60da0
R13: ffff88802ac66fe8 R14: ffff88802ac632e0 R15: ffff88802ac632e0
FS:  0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f593a605718 CR3: 0000000077745000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	48 ba 00 00 00 00 00 	movabs $0xdffffc0000000000,%rdx
   7:	fc ff df
   a:	48 c1 e9 03          	shr    $0x3,%rcx
   e:	80 3c 11 00          	cmpb   $0x0,(%rcx,%rdx,1)
  12:	0f 85 96 01 00 00    	jne    0x1ae
  18:	49 8b b6 08 3d 00 00 	mov    0x3d08(%r14),%rsi
  1f:	49 8d be a8 3d 00 00 	lea    0x3da8(%r14),%rdi
  26:	31 d2                	xor    %edx,%edx
  28:	89 f1                	mov    %esi,%ecx
* 2a:	48 f7 f1             	div    %rcx <-- trapping instruction
  2d:	29 d6                	sub    %edx,%esi
  2f:	b9 05 00 00 00       	mov    $0x5,%ecx
  34:	31 d2                	xor    %edx,%edx
  36:	48 69 f6 e8 03 00 00 	imul   $0x3e8,%rsi,%rsi
  3d:	e8                   	.byte 0xe8
  3e:	2a 39                	sub    (%rcx),%bh

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-selinux-root 2021/12/05 22:30 upstream 944207047ca4 a617004c .config log report info divide error in mac80211_hwsim_bss_info_changed
ci-upstream-net-this-kasan-gce 2021/10/17 08:10 net fac3cb82a54a 0c5d9412 .config log report info divide error in mac80211_hwsim_bss_info_changed
* Struck through repros no longer work on HEAD.