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BUG: KASAN: use-after-free in free_netdev+0x176/0x300 net/core/dev.c:9611
Read of size 8 at addr ffff8881b150c538 by task syz-executor.3/3953
CPU: 0 PID: 3953 Comm: syz-executor.3 Not tainted 5.4.65-syzkaller-00175-g63d1c2f0b547 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1b0/0x21e lib/dump_stack.c:118
print_address_description+0x96/0x5d0 mm/kasan/report.c:374
__kasan_report+0x14b/0x1c0 mm/kasan/report.c:506
kasan_report+0x27/0x50 mm/kasan/common.c:634
free_netdev+0x176/0x300 net/core/dev.c:9611
netdev_run_todo+0xbc4/0xe00 net/core/dev.c:9362
rtnl_unlock net/core/rtnetlink.c:112 [inline]
rtnetlink_rcv_msg+0x963/0xc20 net/core/rtnetlink.c:5256
netlink_rcv_skb+0x1f0/0x460 net/netlink/af_netlink.c:2478
netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
netlink_unicast+0x87c/0xa20 net/netlink/af_netlink.c:1329
netlink_sendmsg+0x9a7/0xd40 net/netlink/af_netlink.c:1918
sock_sendmsg_nosec net/socket.c:638 [inline]
sock_sendmsg net/socket.c:658 [inline]
____sys_sendmsg+0x56f/0x860 net/socket.c:2298
___sys_sendmsg net/socket.c:2352 [inline]
__sys_sendmsg+0x26a/0x350 net/socket.c:2398
do_syscall_64+0xcb/0x150 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45d5f9
Code: 5d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f240f17fc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000002cf00 RCX: 000000000045d5f9
RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000005
RBP: 000000000118d020 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cfec
R13: 00007fffe2557fff R14: 00007f240f1809c0 R15: 000000000118cfec
Allocated by task 3945:
save_stack mm/kasan/common.c:69 [inline]
set_track mm/kasan/common.c:77 [inline]
__kasan_kmalloc+0x117/0x1b0 mm/kasan/common.c:510
__kmalloc+0xf7/0x2c0 mm/slub.c:3848
kmalloc include/linux/slab.h:561 [inline]
sk_prot_alloc+0xd6/0x290 net/core/sock.c:1605
sk_alloc+0x33/0x340 net/core/sock.c:1659
tun_chr_open+0x77/0x4a0 drivers/net/tun.c:3425
misc_open+0x356/0x3d0 drivers/char/misc.c:141
chrdev_open+0x60a/0x670 fs/char_dev.c:414
do_dentry_open+0x8fa/0x1070 fs/open.c:797
do_last fs/namei.c:3495 [inline]
path_openat+0x165b/0x4270 fs/namei.c:3612
do_filp_open+0x1f7/0x430 fs/namei.c:3642
do_sys_open+0x343/0x620 fs/open.c:1094
do_syscall_64+0xcb/0x150 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Freed by task 3942:
save_stack mm/kasan/common.c:69 [inline]
set_track mm/kasan/common.c:77 [inline]
kasan_set_free_info mm/kasan/common.c:332 [inline]
__kasan_slab_free+0x168/0x220 mm/kasan/common.c:471
slab_free_hook mm/slub.c:1443 [inline]
slab_free_freelist_hook+0xd0/0x150 mm/slub.c:1476
slab_free mm/slub.c:3041 [inline]
kfree+0x12b/0x5d0 mm/slub.c:4002
sk_prot_free net/core/sock.c:1642 [inline]
__sk_destruct+0x3f9/0x480 net/core/sock.c:1727
tun_detach drivers/net/tun.c:740 [inline]
tun_chr_close+0xb4/0xd0 drivers/net/tun.c:3461
__fput+0x27d/0x6c0 fs/file_table.c:280
task_work_run+0x176/0x1a0 kernel/task_work.c:113
tracehook_notify_resume include/linux/tracehook.h:188 [inline]
exit_to_usermode_loop arch/x86/entry/common.c:163 [inline]
prepare_exit_to_usermode+0x286/0x2e0 arch/x86/entry/common.c:194
entry_SYSCALL_64_after_hwframe+0x44/0xa9
The buggy address belongs to the object at ffff8881b150c000
which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1336 bytes inside of
2048-byte region [ffff8881b150c000, ffff8881b150c800)
The buggy address belongs to the page:
page:ffffea0006c54200 refcount:1 mapcount:0 mapping:ffff8881da80c000 index:0x0 compound_mapcount: 0
flags: 0x8000000000010200(slab|head)
raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881da80c000
raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff8881b150c400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881b150c480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881b150c500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8881b150c580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881b150c600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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