Subject: [syzbot] general protection fault in hwsim_exit_net

From: syzbot <[email-masked]>
Date: Mon, 26 Jul 2021 07:38:25 -0700

Hello,

syzbot found the following issue on:

HEAD commit:    3d5895cd3517 Merge tag 's390-5.14-3' of git://git.kernel.o..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=107699a6300000
kernel config:  https://syzkaller.appspot.com/x/.config?x=7273c75708b55890
dashboard link: https://syzkaller.appspot.com/bug?extid=78dd535cdc52a06948f7
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1
userspace arch: i386

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]

general protection fault, probably for non-canonical address 0xdffffc00000000df: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x00000000000006f8-0x00000000000006ff]
CPU: 0 PID: 19531 Comm: kworker/u4:5 Not tainted 5.14.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
RIP: 0010:read_pnet include/net/net_namespace.h:325 [inline]
RIP: 0010:wiphy_net include/net/cfg80211.h:5107 [inline]
RIP: 0010:hwsim_exit_net+0x160/0xca0 drivers/net/wireless/mac80211_hwsim.c:4201
Code: 8b 73 18 49 8d 7e 40 48 89 f8 48 c1 e8 03 80 3c 28 00 0f 85 2a 0a 00 00 4d 8b 76 40 49 8d be f8 06 00 00 48 89 f8 48 c1 e8 03 <80> 3c 28 00 0f 85 04 0a 00 00 48 8b 44 24 08 49 3b 86 f8 06 00 00
RSP: 0018:ffffc9000ad5fb18 EFLAGS: 00010202
RAX: 00000000000000df RBX: ffff888000173260 RCX: 0000000000000000
RDX: ffff88806c08d4c0 RSI: ffffffff8532af70 RDI: 00000000000006f8
RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000003
R10: fffff520015abf55 R11: 0000000000086088 R12: ffff888151b83260
R13: ffff888000173260 R14: 0000000000000000 R15: fffffbfff18ef7dc
FS:  0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000090d52c5 CR3: 000000006769c000 CR4: 00000000001526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 ops_exit_list+0xb0/0x160 net/core/net_namespace.c:175
 cleanup_net+0x4ea/0xb10 net/core/net_namespace.c:595
 process_one_work+0x98d/0x1630 kernel/workqueue.c:2276
 worker_thread+0x658/0x11f0 kernel/workqueue.c:2422
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Modules linked in:
---[ end trace a4f6519c3ad068a3 ]---
RIP: 0010:read_pnet include/net/net_namespace.h:325 [inline]
RIP: 0010:wiphy_net include/net/cfg80211.h:5107 [inline]
RIP: 0010:hwsim_exit_net+0x160/0xca0 drivers/net/wireless/mac80211_hwsim.c:4201
Code: 8b 73 18 49 8d 7e 40 48 89 f8 48 c1 e8 03 80 3c 28 00 0f 85 2a 0a 00 00 4d 8b 76 40 49 8d be f8 06 00 00 48 89 f8 48 c1 e8 03 <80> 3c 28 00 0f 85 04 0a 00 00 48 8b 44 24 08 49 3b 86 f8 06 00 00
RSP: 0018:ffffc9000ad5fb18 EFLAGS: 00010202
RAX: 00000000000000df RBX: ffff888000173260 RCX: 0000000000000000
RDX: ffff88806c08d4c0 RSI: ffffffff8532af70 RDI: 00000000000006f8
RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000003
R10: fffff520015abf55 R11: 0000000000086088 R12: ffff888151b83260
R13: ffff888000173260 R14: 0000000000000000 R15: fffffbfff18ef7dc
FS:  0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000090d52c5 CR3: 000000006769c000 CR4: 00000000001526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

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