KASAN: out-of-bounds Read in netdevice_event_work_handler

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: e22d7f05 libbpf: Clarify kernel type use with USER variant..
git tree: bpf-next
console output: https://syzkaller.appspot.com/x/log.txt?x=111fa007500000
kernel config: https://syzkaller.appspot.com/x/.config?x=bacfc914704718d3
dashboard link: https://syzkaller.appspot.com/bug?extid=01117ebae6833fae5c67
compiler: gcc (GCC) 10.1.0-syz 20200507
CC: [ap42...@gmail.com da...@davemloft.net dled...@redhat.com j...@ziepe.ca linux-...@vger.kernel.org linux...@vger.kernel.org net...@vger.kernel.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+01117e...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: out-of-bounds in dev_put include/linux/netdevice.h:3965 [inline]
BUG: KASAN: out-of-bounds in netdevice_event_work_handler+0x15b/0x1b0 drivers/infiniband/core/roce_gid_mgmt.c:630
Read of size 8 at addr ffff888075ae0568 by task kworker/u4:0/8

CPU: 1 PID: 8 Comm: kworker/u4:0 Not tainted 5.11.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: gid-cache-wq netdevice_event_work_handler
Call Trace:
__dump_stack lib/dump_stack.c:79 [inline]
dump_stack+0x107/0x163 lib/dump_stack.c:120
print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:230
__kasan_report mm/kasan/report.c:396 [inline]
kasan_report.cold+0x79/0xd5 mm/kasan/report.c:413
dev_put include/linux/netdevice.h:3965 [inline]
netdevice_event_work_handler+0x15b/0x1b0 drivers/infiniband/core/roce_gid_mgmt.c:630
process_one_work+0x98d/0x15f0 kernel/workqueue.c:2275
worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
kthread+0x3b1/0x4a0 kernel/kthread.c:292
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

The buggy address belongs to the page:
page:00000000e266a168 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888018036700 pfn:0x75ae0
flags: 0xfff00000000000()
raw: 00fff00000000000 dead000000000100 dead000000000122 0000000000000000
raw: ffff888018036700 0000000000000000 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff888075ae0400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888075ae0480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888075ae0500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
^
ffff888075ae0580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888075ae0600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

[syzbot]

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