Subject: [syzbot] divide error in mac80211_hwsim_bss_info_changed

From: syzbot <[email-masked]>
Date: Mon, 17 May 2021 03:45:32 -0700

Hello,

syzbot found the following issue on:

HEAD commit:    eebe426d Merge tag 'fixes-for-5.12-rc7' of git://git.kerne..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15e73ceed00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=9c3d8981d2bdb103
dashboard link: https://syzkaller.appspot.com/bug?extid=26727b5e00947e02242c
compiler:       Debian clang version 11.0.1-2

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

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email-masked]

divide error: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 13049 Comm: kworker/u4:16 Not tainted 5.12.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: phy10 ieee80211_roc_work
RIP: 0010:mac80211_hwsim_bss_info_changed+0x514/0xf90 drivers/net/wireless/mac80211_hwsim.c:2024
Code: 48 b8 00 00 00 00 00 fc ff df 80 7c 05 00 00 74 0a 48 8b 7c 24 08 e8 9b a6 68 fc 48 8b 44 24 08 48 8b 08 89 ce 48 89 d8 31 d2 <48> f7 f6 29 d1 48 69 f1 e8 03 00 00 48 8b 7c 24 10 31 d2 b9 05 00
RSP: 0018:ffffc900023bfb88 EFLAGS: 00010246
RAX: 0005bfe4b761f015 RBX: 0005bfe4b761f015 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000040
RBP: 1ffff11004556dcf R08: ffffffff81698b49 R09: fffffbfff1f272bd
R10: fffffbfff1f272bd R11: 0000000000000000 R12: ffff888022ab0d50
R13: 0000000000000200 R14: ffff888022ab6fd8 R15: 1ffff110045561aa
FS:  0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000543038 CR3: 000000007746b000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 drv_bss_info_changed net/mac80211/driver-ops.h:177 [inline]
 ieee80211_bss_info_change_notify+0x27c/0x3a0 net/mac80211/main.c:210
 ieee80211_offchannel_return+0x33b/0x470 net/mac80211/offchannel.c:158
 __ieee80211_roc_work+0x282/0x340 net/mac80211/offchannel.c:444
 ieee80211_roc_work+0x2b/0x40 net/mac80211/offchannel.c:458
 process_one_work+0x789/0xfd0 kernel/workqueue.c:2275
 worker_thread+0xac1/0x1300 kernel/workqueue.c:2421
 kthread+0x39a/0x3c0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
Modules linked in:
---[ end trace 2380ddc5fa748069 ]---
RIP: 0010:mac80211_hwsim_bss_info_changed+0x514/0xf90 drivers/net/wireless/mac80211_hwsim.c:2024
Code: 48 b8 00 00 00 00 00 fc ff df 80 7c 05 00 00 74 0a 48 8b 7c 24 08 e8 9b a6 68 fc 48 8b 44 24 08 48 8b 08 89 ce 48 89 d8 31 d2 <48> f7 f6 29 d1 48 69 f1 e8 03 00 00 48 8b 7c 24 10 31 d2 b9 05 00
RSP: 0018:ffffc900023bfb88 EFLAGS: 00010246
RAX: 0005bfe4b761f015 RBX: 0005bfe4b761f015 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000040
RBP: 1ffff11004556dcf R08: ffffffff81698b49 R09: fffffbfff1f272bd
R10: fffffbfff1f272bd R11: 0000000000000000 R12: ffff888022ab0d50
R13: 0000000000000200 R14: ffff888022ab6fd8 R15: 1ffff110045561aa
FS:  0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000219a708 CR3: 000000007746b000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

---
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