[syzbot] divide error in mac80211_hwsim_config

From: syzbot
Date: Mon Dec 06 2021 - 20:19:32 EST


Hello,

syzbot found the following issue on:

HEAD commit: fc993be36f9e Merge git://git.kernel.org/pub/scm/linux/kern..
git tree: net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=147b18c5b00000
kernel config: https://syzkaller.appspot.com/x/.config?x=b5949d4891208a1b
dashboard link: https://syzkaller.appspot.com/bug?extid=befa3d613df263396a0c
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2

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: syzbot+befa3d613df263396a0c@xxxxxxxxxxxxxxxxxxxxxxxxx

divide error: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 5890 Comm: syz-executor.0 Not tainted 5.16.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:mac80211_hwsim_config+0x7fd/0xdb0 drivers/net/wireless/mac80211_hwsim.c:1957
Code: 48 ba 00 00 00 00 00 fc ff df 48 c1 e9 03 80 3c 11 00 0f 85 1a 03 00 00 48 8b b5 08 3d 00 00 48 8d bd 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 db a8
RSP: 0018:ffffc9000281fac0 EFLAGS: 00010246
RAX: 0005d233ac620269 RBX: ffff8880795fb2e0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880795ff088
RBP: ffff8880795fb2e0 R08: 000000000006cc08 R09: ffffffff8ff7ca67
R10: ffffffff8167b17f R11: 0000000000000036 R12: ffff8880795fefe8
R13: ffff8880795f8da0 R14: 1ffff92000503f6a R15: 0000000000000014
FS: 00007f8fcd540700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2c820000 CR3: 00000000249cd000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
drv_config net/mac80211/driver-ops.h:145 [inline]
ieee80211_hw_config+0x840/0x1480 net/mac80211/main.c:181
ieee80211_set_wiphy_params+0x4d7/0xdb0 net/mac80211/cfg.c:2688
rdev_set_wiphy_params+0x125/0x390 net/wireless/rdev-ops.h:569
cfg80211_wext_siwretry net/wireless/wext-compat.c:369 [inline]
__cfg80211_wext_siwretry+0x2c6/0x5d0 net/wireless/wext-compat.c:1584
ioctl_standard_call+0xcd/0x1f0 net/wireless/wext-core.c:1017
wireless_process_ioctl+0xc8/0x4c0 net/wireless/wext-core.c:955
wext_ioctl_dispatch net/wireless/wext-core.c:988 [inline]
wext_ioctl_dispatch net/wireless/wext-core.c:976 [inline]
wext_handle_ioctl+0x26b/0x280 net/wireless/wext-core.c:1049
sock_ioctl+0x285/0x640 net/socket.c:1169
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f8fcffcaae9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f8fcd540188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f8fd00ddf60 RCX: 00007f8fcffcaae9
RDX: 0000000020000000 RSI: 0000000000008b28 RDI: 0000000000000005
RBP: 00007f8fd0024f6d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd1c29a66f R14: 00007f8fcd540300 R15: 0000000000022000
</TASK>
Modules linked in:
---[ end trace 7b3003b6289f2375 ]---
RIP: 0010:mac80211_hwsim_config+0x7fd/0xdb0 drivers/net/wireless/mac80211_hwsim.c:1957
Code: 48 ba 00 00 00 00 00 fc ff df 48 c1 e9 03 80 3c 11 00 0f 85 1a 03 00 00 48 8b b5 08 3d 00 00 48 8d bd 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 db a8
RSP: 0018:ffffc9000281fac0 EFLAGS: 00010246
RAX: 0005d233ac620269 RBX: ffff8880795fb2e0 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880795ff088
RBP: ffff8880795fb2e0 R08: 000000000006cc08 R09: ffffffff8ff7ca67
R10: ffffffff8167b17f R11: 0000000000000036 R12: ffff8880795fefe8
R13: ffff8880795f8da0 R14: 1ffff92000503f6a R15: 0000000000000014
FS: 00007f8fcd540700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdba49e7012 CR3: 00000000249cd000 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 1a 03 00 00 jne 0x332
18: 48 8b b5 08 3d 00 00 mov 0x3d08(%rbp),%rsi
1f: 48 8d bd a8 3d 00 00 lea 0x3da8(%rbp),%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: db .byte 0xdb
3f: a8 .byte 0xa8


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