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BUG: KASAN: slab-use-after-free in netdev_need_ops_lock include/net/netdev_lock.h:33 [inline]
BUG: KASAN: slab-use-after-free in netdev_unlock_ops include/net/netdev_lock.h:47 [inline]
BUG: KASAN: slab-use-after-free in __linkwatch_run_queue+0x880/0x8a0 net/core/link_watch.c:245
Read of size 8 at addr ffff88805799c008 by task kworker/u8:1/13

CPU: 0 UID: 0 PID: 13 Comm: kworker/u8:1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: events_unbound linkwatch_event
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xcd/0x630 mm/kasan/report.c:482
 kasan_report+0xe0/0x110 mm/kasan/report.c:595
 netdev_need_ops_lock include/net/netdev_lock.h:33 [inline]
 netdev_unlock_ops include/net/netdev_lock.h:47 [inline]
 __linkwatch_run_queue+0x880/0x8a0 net/core/link_watch.c:245
 linkwatch_event+0x8f/0xc0 net/core/link_watch.c:304
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Allocated by task 5514:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:388 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:405
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4365 [inline]
 __kmalloc_node_track_caller_noprof+0x221/0x510 mm/slub.c:4384
 kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:600
 __alloc_skb+0x166/0x380 net/core/skbuff.c:669
 alloc_skb include/linux/skbuff.h:1336 [inline]
 alloc_skb_with_frags+0xe0/0x860 net/core/skbuff.c:6665
 sock_alloc_send_pskb+0x7fb/0x990 net/core/sock.c:2980
 unix_dgram_sendmsg+0x3e9/0x17f0 net/unix/af_unix.c:2153
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg net/socket.c:729 [inline]
 __sys_sendto+0x4a0/0x520 net/socket.c:2228
 __do_sys_sendto net/socket.c:2235 [inline]
 __se_sys_sendto net/socket.c:2231 [inline]
 __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2231
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5201:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:243 [inline]
 __kasan_slab_free+0x60/0x70 mm/kasan/common.c:275
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2417 [inline]
 slab_free mm/slub.c:4680 [inline]
 kfree+0x2b4/0x4d0 mm/slub.c:4879
 skb_kfree_head net/core/skbuff.c:1047 [inline]
 skb_free_head+0x114/0x210 net/core/skbuff.c:1059
 skb_release_data+0x795/0x9e0 net/core/skbuff.c:1086
 skb_release_all net/core/skbuff.c:1151 [inline]
 __kfree_skb net/core/skbuff.c:1165 [inline]
 consume_skb net/core/skbuff.c:1397 [inline]
 consume_skb+0xbf/0x100 net/core/skbuff.c:1391
 __unix_dgram_recvmsg+0x779/0xc30 net/unix/af_unix.c:2683
 unix_dgram_recvmsg+0xd0/0x110 net/unix/af_unix.c:2700
 sock_recvmsg_nosec net/socket.c:1065 [inline]
 sock_recvmsg+0x1f9/0x250 net/socket.c:1087
 sock_read_iter+0x2b9/0x3b0 net/socket.c:1157
 new_sync_read fs/read_write.c:491 [inline]
 vfs_read+0xa95/0xcf0 fs/read_write.c:572
 ksys_read+0x1f8/0x250 fs/read_write.c:715
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88805799c000
 which belongs to the cache kmalloc-cg-512 of size 512
The buggy address is located 8 bytes inside of
 freed 512-byte region [ffff88805799c000, ffff88805799c200)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5799c
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff8880587f2301
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801b84b140 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000100010 00000000f5000000 ffff8880587f2301
head: 00fff00000000040 ffff88801b84b140 dead000000000122 0000000000000000
head: 0000000000000000 0000000000100010 00000000f5000000 ffff8880587f2301
head: 00fff00000000002 ffffea00015e6701 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5514, tgid 5514 (dhcpcd), ts 128837065175, free_ts 128795328870
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1851
 prep_new_page mm/page_alloc.c:1859 [inline]
 get_page_from_freelist+0x132b/0x38e0 mm/page_alloc.c:3858
 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:5148
 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416
 alloc_slab_page mm/slub.c:2487 [inline]
 allocate_slab mm/slub.c:2655 [inline]
 new_slab+0x247/0x330 mm/slub.c:2709
 ___slab_alloc+0xcf2/0x1740 mm/slub.c:3891
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3981
 __slab_alloc_node mm/slub.c:4056 [inline]
 slab_alloc_node mm/slub.c:4217 [inline]
 __do_kmalloc_node mm/slub.c:4364 [inline]
 __kmalloc_node_track_caller_noprof+0x2ee/0x510 mm/slub.c:4384
 kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:600
 __alloc_skb+0x166/0x380 net/core/skbuff.c:669
 alloc_skb include/linux/skbuff.h:1336 [inline]
 alloc_skb_with_frags+0xe0/0x860 net/core/skbuff.c:6665
 sock_alloc_send_pskb+0x7fb/0x990 net/core/sock.c:2980
 unix_dgram_sendmsg+0x3e9/0x17f0 net/unix/af_unix.c:2153
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg net/socket.c:729 [inline]
 __sys_sendto+0x4a0/0x520 net/socket.c:2228
 __do_sys_sendto net/socket.c:2235 [inline]
 __se_sys_sendto net/socket.c:2231 [inline]
 __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2231
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
page last free pid 6988 tgid 6987 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0x7d5/0x10f0 mm/page_alloc.c:2895
 device_release+0xa4/0x240 drivers/base/core.c:2565
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x1e7/0x5a0 lib/kobject.c:737
 netdev_run_todo+0x7e9/0x1320 net/core/dev.c:11513
 tun_detach drivers/net/tun.c:640 [inline]
 tun_chr_close+0xea/0x230 drivers/net/tun.c:3433
 __fput+0x402/0xb70 fs/file_table.c:468
 fput_close_sync+0x118/0x210 fs/file_table.c:573
 __do_sys_close fs/open.c:1587 [inline]
 __se_sys_close fs/open.c:1572 [inline]
 __x64_sys_close+0x8b/0x120 fs/open.c:1572
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88805799bf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88805799bf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88805799c000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                      ^
 ffff88805799c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88805799c100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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