KASAN: use-after-free Read in netdevice_event_work_handler

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: b86ee2b7ae42 Linux 4.14.264
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=10940084700000
kernel config: https://syzkaller.appspot.com/x/.config?x=3fffc4e0823c0d50
dashboard link: https://syzkaller.appspot.com/bug?extid=2201905e76e846cacf25
compiler: gcc version 10.2.1 20210110 (Debian 10.2.1-6)

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+220190...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: use-after-free in dev_put include/linux/netdevice.h:3380 [inline]
BUG: KASAN: use-after-free in netdevice_event_work_handler+0x14d/0x1a0 drivers/infiniband/core/roce_gid_mgmt.c:539
Read of size 8 at addr ffff8880930fe880 by task kworker/u4:0/5

CPU: 0 PID: 5 Comm: kworker/u4:0 Not tainted 4.14.264-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:17 [inline]
dump_stack+0x1b2/0x281 lib/dump_stack.c:58
print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252
kasan_report_error.cold+0x8a/0x191 mm/kasan/report.c:351
kasan_report mm/kasan/report.c:409 [inline]
__asan_report_load8_noabort+0x68/0x70 mm/kasan/report.c:430
dev_put include/linux/netdevice.h:3380 [inline]
netdevice_event_work_handler+0x14d/0x1a0 drivers/infiniband/core/roce_gid_mgmt.c:539
process_one_work+0x793/0x14a0 kernel/workqueue.c:2117
worker_thread+0x5cc/0xff0 kernel/workqueue.c:2251
kthread+0x30d/0x420 kernel/kthread.c:232
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404

Allocated by task 9857:
save_stack mm/kasan/kasan.c:447 [inline]
set_track mm/kasan/kasan.c:459 [inline]
kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551
__do_kmalloc_node mm/slab.c:3682 [inline]
__kmalloc_node+0x4c/0x70 mm/slab.c:3689
kmalloc_node include/linux/slab.h:530 [inline]
kvmalloc_node+0x46/0xd0 mm/util.c:397
kvmalloc include/linux/mm.h:531 [inline]
kvzalloc include/linux/mm.h:539 [inline]
alloc_netdev_mqs+0x76/0xb70 net/core/dev.c:8112
rtnl_create_link+0x1ab/0x890 net/core/rtnetlink.c:2460
rtnl_newlink+0xea9/0x1860 net/core/rtnetlink.c:2718
rtnetlink_rcv_msg+0x3be/0xb10 net/core/rtnetlink.c:4320
netlink_rcv_skb+0x125/0x390 net/netlink/af_netlink.c:2446
netlink_unicast_kernel net/netlink/af_netlink.c:1294 [inline]
netlink_unicast+0x437/0x610 net/netlink/af_netlink.c:1320
netlink_sendmsg+0x648/0xbc0 net/netlink/af_netlink.c:1891
sock_sendmsg_nosec net/socket.c:646 [inline]
sock_sendmsg+0xb5/0x100 net/socket.c:656
___sys_sendmsg+0x6c8/0x800 net/socket.c:2062
__sys_sendmsg+0xa3/0x120 net/socket.c:2096
SYSC_sendmsg net/socket.c:2107 [inline]
SyS_sendmsg+0x27/0x40 net/socket.c:2103
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb

Freed by task 9857:
save_stack mm/kasan/kasan.c:447 [inline]
set_track mm/kasan/kasan.c:459 [inline]
kasan_slab_free+0xc3/0x1a0 mm/kasan/kasan.c:524
__cache_free mm/slab.c:3496 [inline]
kfree+0xc9/0x250 mm/slab.c:3815
kvfree+0x45/0x50 mm/util.c:416
device_release+0x15f/0x1a0 drivers/base/core.c:848
kobject_cleanup lib/kobject.c:646 [inline]
kobject_release lib/kobject.c:675 [inline]
kref_put include/linux/kref.h:70 [inline]
kobject_put+0x251/0x550 lib/kobject.c:692
put_device+0x1c/0x30 drivers/base/core.c:2030
free_netdev+0x26f/0x360 net/core/dev.c:8234
rtnl_newlink+0x14e6/0x1860 net/core/rtnetlink.c:2744
rtnetlink_rcv_msg+0x3be/0xb10 net/core/rtnetlink.c:4320
netlink_rcv_skb+0x125/0x390 net/netlink/af_netlink.c:2446
netlink_unicast_kernel net/netlink/af_netlink.c:1294 [inline]
netlink_unicast+0x437/0x610 net/netlink/af_netlink.c:1320
netlink_sendmsg+0x648/0xbc0 net/netlink/af_netlink.c:1891
sock_sendmsg_nosec net/socket.c:646 [inline]
sock_sendmsg+0xb5/0x100 net/socket.c:656
___sys_sendmsg+0x6c8/0x800 net/socket.c:2062
__sys_sendmsg+0xa3/0x120 net/socket.c:2096
SYSC_sendmsg net/socket.c:2107 [inline]
SyS_sendmsg+0x27/0x40 net/socket.c:2103
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x46/0xbb

The buggy address belongs to the object at ffff8880930fe340
which belongs to the cache kmalloc-4096 of size 4096
The buggy address is located 1344 bytes inside of
4096-byte region [ffff8880930fe340, ffff8880930ff340)
The buggy address belongs to the page:
page:ffffea00024c3f80 count:1 mapcount:0 mapping:ffff8880930fe340 index:0x0 compound_mapcount: 0
flags: 0xfff00000008100(slab|head)
raw: 00fff00000008100 ffff8880930fe340 0000000000000000 0000000100000001
raw: ffffea0002ab35a0 ffffea000242e0a0 ffff88813fe74dc0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff8880930fe780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880930fe800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880930fe880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8880930fe900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880930fe980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


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[syzbot]

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