Subject: WARNING in chnl_net_uninit

From: syzbot <[email-masked]>
Date: Mon, 31 Aug 2020 09:58:21 -0700

Hello,

syzbot found the following issue on:

HEAD commit:    4d41ead6 Merge tag 'block-5.9-2020-08-28' of git://git.ker..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=100cf1de900000
kernel config:  https://syzkaller.appspot.com/x/.config?x=5ebdb650dfa501c1
dashboard link: https://syzkaller.appspot.com/bug?extid=ef72fb13d1c081833ebe
compiler:       gcc (GCC) 10.1.0-syz 20200507
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]

------------[ cut here ]------------
WARNING: CPU: 3 PID: 11918 at net/caif/chnl_net.c:67 robust_list_del net/caif/chnl_net.c:67 [inline]
WARNING: CPU: 3 PID: 11918 at net/caif/chnl_net.c:67 chnl_net_uninit+0xc9/0x2dc net/caif/chnl_net.c:380
Kernel panic - not syncing: panic_on_warn set ...
CPU: 2 PID: 11918 Comm: syz-executor.1 Not tainted 5.9.0-rc2-syzkaller #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x18f/0x20d lib/dump_stack.c:118
 panic+0x2e3/0x75c kernel/panic.c:231
 __warn.cold+0x20/0x4a kernel/panic.c:600
 report_bug+0x1bd/0x210 lib/bug.c:198
 handle_bug+0x38/0x90 arch/x86/kernel/traps.c:234
 exc_invalid_op+0x14/0x40 arch/x86/kernel/traps.c:254
 asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:536
RIP: 0010:robust_list_del net/caif/chnl_net.c:67 [inline]
RIP: 0010:chnl_net_uninit+0xc9/0x2dc net/caif/chnl_net.c:380
Code: 89 eb e8 3a 44 b0 f9 48 89 d8 48 c1 e8 03 42 80 3c 28 00 0f 85 bf 01 00 00 48 81 fb 60 ba a5 8a 48 8b 2b 75 d0 e8 17 44 b0 f9 <0f> 0b 5b 5d 41 5c 41 5d e9 0a 44 b0 f9 4c 89 e3 e8 02 44 b0 f9 4c
RSP: 0000:ffffc90001707070 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffffffff8aa5ba60 RCX: ffffffff87c3fa72
RDX: ffff88802797d800 RSI: ffffffff87c3faf9 RDI: 0000000000000005
RBP: ffffffff8aa5ba60 R08: 0000000000000000 R09: ffffffff8a7e73e7
R10: 0000000000000000 R11: 0000000000000001 R12: ffff88805fdd6d88
R13: ffff88805fdd6000 R14: dffffc0000000000 R15: ffff888023b07f80
 rollback_registered_many+0xa7a/0x1210 net/core/dev.c:9300

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