general protection fault in addrconf_verify_rtnl

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: a1b8638b Linux 5.9-rc7
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1066b237900000
kernel config: https://syzkaller.appspot.com/x/.config?x=41b736b7ce1b3ea4
dashboard link: https://syzkaller.appspot.com/bug?extid=d6facf941acb4510aa4e
compiler: gcc (GCC) 10.1.0-syz 20200507
CC: [da...@davemloft.net ku...@kernel.org kuz...@ms2.inr.ac.ru linux-...@vger.kernel.org net...@vger.kernel.org yosh...@linux-ipv6.org]

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+d6facf...@syzkaller.appspotmail.com

general protection fault, probably for non-canonical address 0xdffffce0e0e0e0c4: 0000 [#1] PREEMPT SMP KASAN
KASAN: probably user-memory-access in range [0x0000070707070620-0x0000070707070627]
CPU: 0 PID: 9932 Comm: kworker/0:4 Not tainted 5.9.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: ipv6_addrconf addrconf_verify_work
RIP: 0010:addrconf_verify_rtnl+0x1b9/0x1290 net/ipv6/addrconf.c:4472
Code: 81 ed 48 01 00 00 0f 84 90 02 00 00 48 8b 44 24 48 48 83 c0 02 48 89 44 24 20 e8 f2 ae 5a fa 4c 8d 65 6c 4c 89 e0 48 c1 e8 03 <42> 0f b6 14 38 4c 89 e0 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85
RSP: 0018:ffffc90016627c80 EFLAGS: 00010203
RAX: 000000e0e0e0e0c4 RBX: 0000000000000001 RCX: ffffffff871b9b0a
RDX: ffff88801d644100 RSI: ffffffff871b8f9e RDI: 0000000000000005
RBP: 00000707070705b8 R08: 0000000000000001 R09: ffffffff8d0c09ff
R10: 0000000000000000 R11: 0000000000000000 R12: 0000070707070624
R13: ffffffff8b2a7170 R14: ffff88809e329400 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880ae400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000001590004 CR3: 000000021b278000 CR4: 00000000001526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
addrconf_verify_work+0xf/0x20 net/ipv6/addrconf.c:4569
process_one_work+0x94c/0x1670 kernel/workqueue.c:2269
worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
kthread+0x3b5/0x4a0 kernel/kthread.c:292
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
Modules linked in:
---[ end trace f8b0cd0d7300fb5a ]---
RIP: 0010:addrconf_verify_rtnl+0x1b9/0x1290 net/ipv6/addrconf.c:4472
Code: 81 ed 48 01 00 00 0f 84 90 02 00 00 48 8b 44 24 48 48 83 c0 02 48 89 44 24 20 e8 f2 ae 5a fa 4c 8d 65 6c 4c 89 e0 48 c1 e8 03 <42> 0f b6 14 38 4c 89 e0 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85
RSP: 0018:ffffc90016627c80 EFLAGS: 00010203
RAX: 000000e0e0e0e0c4 RBX: 0000000000000001 RCX: ffffffff871b9b0a
RDX: ffff88801d644100 RSI: ffffffff871b8f9e RDI: 0000000000000005
RBP: 00000707070705b8 R08: 0000000000000001 R09: ffffffff8d0c09ff
R10: 0000000000000000 R11: 0000000000000000 R12: 0000070707070624
R13: ffffffff8b2a7170 R14: ffff88809e329400 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880ae400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000001590004 CR3: 000000021b278000 CR4: 00000000001526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.