KASAN: use-after-free Read in __dev_queue_xmit

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 21ad423fe521 Linux 4.14.265
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=11d1abaa700000
kernel config: https://syzkaller.appspot.com/x/.config?x=f79494e54ef9cb67
dashboard link: https://syzkaller.appspot.com/bug?extid=5e3e9494824ed3ed35c8
compiler: gcc version 10.2.1 20210110 (Debian 10.2.1-6)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17038252700000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=119d1a8c700000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5e3e94...@syzkaller.appspotmail.com

device bridge1606 entered promiscuous mode
==================================================================
device bridge1607 entered promiscuous mode
BUG: KASAN: use-after-free in __read_once_size include/linux/compiler.h:185 [inline]
BUG: KASAN: use-after-free in skb_update_prio net/core/dev.c:3251 [inline]
BUG: KASAN: use-after-free in __dev_queue_xmit+0x21b7/0x2480 net/core/dev.c:3463
Read of size 8 at addr ffff88804633ccf0 by task aoe_tx0/3072

CPU: 1 PID: 3072 Comm: aoe_tx0 Not tainted 4.14.265-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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
__read_once_size include/linux/compiler.h:185 [inline]
skb_update_prio net/core/dev.c:3251 [inline]
__dev_queue_xmit+0x21b7/0x2480 net/core/dev.c:3463
tx+0x68/0xa0 drivers/block/aoe/aoenet.c:63
kthread+0x1b9/0x350 drivers/block/aoe/aoecmd.c:1259
kthread+0x30d/0x420 kernel/kthread.c:232
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404

Allocated by task 1463:
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+0xe7a/0x1830 net/core/rtnetlink.c:2720
rtnetlink_rcv_msg+0x3be/0xb10 net/core/rtnetlink.c:4322
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 1463:
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
netdev_run_todo+0x747/0xad0 net/core/dev.c:7969
rtnl_unlock net/core/rtnetlink.c:106 [inline]
rtnetlink_rcv_msg+0x3cb/0xb10 net/core/rtnetlink.c:4324
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 ffff88804633c240
which belongs to the cache kmalloc-4096 of size 4096
The buggy address is located 2736 bytes inside of
4096-byte region [ffff88804633c240, ffff88804633d240)
The buggy address belongs to the page:
page:ffffea000118cf00 count:1 mapcount:0 mapping:ffff88804633c240 index:0x0 compound_mapcount: 0
flags: 0xfff00000008100(slab|head)
raw: 00fff00000008100 ffff88804633c240 0000000000000000 0000000100000001
raw: ffffea00012376a0 ffffea000118cfa0 ffff88813fe74dc0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff88804633cb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88804633cc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88804633cc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88804633cd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88804633cd80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


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