KASAN: out-of-bounds Read in netdevice_event_work

KASAN: out-of-bounds Read in netdevice_event_work_handler
Status: moderation: reported on 2021/01/13 12:57
Reported-by: syzbot+01117ebae6833fae5c67@syzkaller.appspotmail.com
First crash: 15d, last: 15d

Sample crash report:

==================================================================
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
==================================================================

Crashes (1):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Maintainers
ci-upstream-bpf-next-kasan-gce	2021/01/09 12:46	bpf-next	e22d7f05	a6c52263	.config	log	report			info	ap420073@gmail.com, davem@davemloft.net, dledford@redhat.com, jgg@ziepe.ca, linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org