netlink: 20 bytes leftover after parsing attributes in process `syz-executor.0'.
==================================================================
BUG: KASAN: use-after-free in free_netdev+0x475/0x510 net/core/dev.c:10659
Read of size 8 at addr ffff88802f8f66f8 by task syz-executor.0/5903

CPU: 1 PID: 5903 Comm: syz-executor.0 Not tainted 5.11.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x9a/0xcc 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
 free_netdev+0x475/0x510 net/core/dev.c:10659
 netdev_run_todo+0x933/0xcd0 net/core/dev.c:10347
 rtnl_unlock net/core/rtnetlink.c:112 [inline]
 rtnetlink_rcv_msg+0x337/0x860 net/core/rtnetlink.c:5554
 netlink_rcv_skb+0x118/0x370 net/netlink/af_netlink.c:2494
 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
 netlink_unicast+0x42e/0x700 net/netlink/af_netlink.c:1330
 netlink_sendmsg+0x70e/0xbe0 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xab/0xe0 net/socket.c:672
 ____sys_sendmsg+0x5bf/0x7a0 net/socket.c:2345
 ___sys_sendmsg+0xd3/0x150 net/socket.c:2399
 __sys_sendmsg+0xb2/0x140 net/socket.c:2432
 do_syscall_64+0x2d/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7ff858028109
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff85779d168 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ff85813af60 RCX: 00007ff858028109
RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000004
RBP: 00007ff85808205d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffcf8f9ad4f R14: 00007ff85779d300 R15: 0000000000022000

Allocated by task 5903:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:401 [inline]
 ____kasan_kmalloc.constprop.0+0x82/0xa0 mm/kasan/common.c:429
 kmalloc include/linux/slab.h:557 [inline]
 sk_prot_alloc+0x133/0x260 net/core/sock.c:1685
 sk_alloc+0x27/0x8d0 net/core/sock.c:1739
 tun_chr_open+0x74/0x520 drivers/net/tun.c:3318
 misc_open+0x2f0/0x410 drivers/char/misc.c:141
 chrdev_open+0x20f/0x650 fs/char_dev.c:414
 do_dentry_open+0x42a/0xfb0 fs/open.c:817
 do_open fs/namei.c:3254 [inline]
 path_openat+0x129c/0x2190 fs/namei.c:3371
 do_filp_open+0x16d/0x390 fs/namei.c:3398
 do_sys_openat2+0x11e/0x360 fs/open.c:1172
 do_sys_open fs/open.c:1188 [inline]
 __do_sys_openat fs/open.c:1204 [inline]
 __se_sys_openat fs/open.c:1199 [inline]
 __x64_sys_openat+0x11b/0x1d0 fs/open.c:1199
 do_syscall_64+0x2d/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 5904:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38
 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46
 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:356
 ____kasan_slab_free+0xe1/0x110 mm/kasan/common.c:362
 kasan_slab_free include/linux/kasan.h:192 [inline]
 slab_free_hook mm/slub.c:1547 [inline]
 slab_free_freelist_hook+0x5d/0x150 mm/slub.c:1580
 slab_free mm/slub.c:3143 [inline]
 kfree+0xdb/0x3b0 mm/slub.c:4139
 sk_prot_free net/core/sock.c:1722 [inline]
 __sk_destruct+0x53f/0x730 net/core/sock.c:1807
 tun_detach drivers/net/tun.c:679 [inline]
 tun_chr_close+0xda/0x150 drivers/net/tun.c:3354
 __fput+0x204/0x870 fs/file_table.c:280
 task_work_run+0xc0/0x160 kernel/task_work.c:140
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:174 [inline]
 exit_to_user_mode_prepare+0x249/0x250 kernel/entry/common.c:201
 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff88802f8f6000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 1784 bytes inside of
 4096-byte region [ffff88802f8f6000, ffff88802f8f7000)
The buggy address belongs to the page:
page:00000000baa31fd8 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2f8f0
head:00000000baa31fd8 order:3 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head)
raw: 00fff00000010200 0000000000000000 0000000100000001 ffff88800f442140
raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5433, ts 40303590392
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x144/0x1c0 mm/page_alloc.c:2297
 prep_new_page mm/page_alloc.c:2306 [inline]
 get_page_from_freelist+0x1c6e/0x3f80 mm/page_alloc.c:3945
 __alloc_pages_nodemask+0x2d6/0x730 mm/page_alloc.c:4995
 alloc_pages include/linux/gfp.h:547 [inline]
 alloc_slab_page mm/slub.c:1618 [inline]
 allocate_slab+0x2b6/0x4a0 mm/slub.c:1758
 new_slab mm/slub.c:1821 [inline]
 new_slab_objects mm/slub.c:2578 [inline]
 ___slab_alloc+0x476/0x790 mm/slub.c:2741
 __slab_alloc.constprop.0+0x95/0xe0 mm/slub.c:2781
 slab_alloc_node mm/slub.c:2857 [inline]
 slab_alloc mm/slub.c:2900 [inline]
 kmem_cache_alloc_trace+0x2cc/0x360 mm/slub.c:2917
 kmalloc include/linux/slab.h:552 [inline]
 tomoyo_print_header security/tomoyo/audit.c:156 [inline]
 tomoyo_init_log+0x183/0x1d20 security/tomoyo/audit.c:255
 tomoyo_supervisor+0x2fc/0xc40 security/tomoyo/common.c:2097
 tomoyo_audit_path_number_log security/tomoyo/file.c:235 [inline]
 tomoyo_path_number_perm+0x38a/0x4d0 security/tomoyo/file.c:734
 security_file_ioctl+0x44/0x80 security/security.c:1482
 __do_sys_ioctl fs/ioctl.c:747 [inline]
 __se_sys_ioctl fs/ioctl.c:739 [inline]
 __x64_sys_ioctl+0x99/0x190 fs/ioctl.c:739
 do_syscall_64+0x2d/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88802f8f6580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802f8f6600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88802f8f6680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                                ^
 ffff88802f8f6700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802f8f6780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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