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BUG: KASAN: slab-out-of-bounds in __lock_acquire+0x3c88/0x5230 kernel/locking/lockdep.c:4771
Read of size 8 at addr ffff8880734ff0a0 by task kworker/1:7/9698

CPU: 1 PID: 9698 Comm: kworker/1:7 Not tainted 5.12.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events l2cap_chan_timeout
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x141/0x1d7 lib/dump_stack.c:120
 print_address_description.constprop.0.cold+0x5b/0x2c6 mm/kasan/report.c:233
 __kasan_report mm/kasan/report.c:419 [inline]
 kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:436
 __lock_acquire+0x3c88/0x5230 kernel/locking/lockdep.c:4771
 lock_acquire kernel/locking/lockdep.c:5511 [inline]
 lock_acquire+0x1ab/0x740 kernel/locking/lockdep.c:5476
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
 _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:175
 spin_lock_bh include/linux/spinlock.h:359 [inline]
 lock_sock_nested+0x40/0x120 net/core/sock.c:3057
 l2cap_sock_teardown_cb+0xa1/0x660 net/bluetooth/l2cap_sock.c:1520
 l2cap_chan_del+0xbc/0xa80 net/bluetooth/l2cap_core.c:618
 l2cap_chan_close+0x1bc/0xaf0 net/bluetooth/l2cap_core.c:823
 l2cap_chan_timeout+0x17e/0x2f0 net/bluetooth/l2cap_core.c:436
 process_one_work+0x98d/0x1600 kernel/workqueue.c:2275
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Allocated by task 8375:
 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:427 [inline]
 __kasan_slab_alloc+0x73/0x90 mm/kasan/common.c:460
 kasan_slab_alloc include/linux/kasan.h:223 [inline]
 slab_post_alloc_hook mm/slab.h:516 [inline]
 slab_alloc_node mm/slab.c:3262 [inline]
 kmem_cache_alloc_node+0x1e5/0x540 mm/slab.c:3594
 __alloc_skb+0x20b/0x340 net/core/skbuff.c:412
 alloc_skb_fclone include/linux/skbuff.h:1153 [inline]
 sk_stream_alloc_skb+0x109/0xc30 net/ipv4/tcp.c:886
 tcp_sendmsg_locked+0xc00/0x2e40 net/ipv4/tcp.c:1308
 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1457
 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:821
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:674
 sock_write_iter+0x289/0x3c0 net/socket.c:1001
 call_write_iter include/linux/fs.h:1977 [inline]
 new_sync_write+0x426/0x650 fs/read_write.c:518
 vfs_write+0x796/0xa30 fs/read_write.c:605
 ksys_write+0x1ee/0x250 fs/read_write.c:658
 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Freed by task 8375:
 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:357
 ____kasan_slab_free mm/kasan/common.c:360 [inline]
 ____kasan_slab_free mm/kasan/common.c:325 [inline]
 __kasan_slab_free+0xc7/0x100 mm/kasan/common.c:367
 kasan_slab_free include/linux/kasan.h:199 [inline]
 __cache_free mm/slab.c:3440 [inline]
 kmem_cache_free+0x6d/0x1f0 mm/slab.c:3733
 kfree_skbmem+0x166/0x1b0 net/core/skbuff.c:704
 sk_wmem_free_skb include/net/sock.h:1562 [inline]
 tcp_rtx_queue_unlink_and_free include/net/tcp.h:1878 [inline]
 tcp_clean_rtx_queue net/ipv4/tcp_input.c:3268 [inline]
 tcp_ack+0x1c3d/0x5970 net/ipv4/tcp_input.c:3813
 tcp_rcv_established+0x130e/0x1eb0 net/ipv4/tcp_input.c:5796
 tcp_v4_do_rcv+0x5d1/0x870 net/ipv4/tcp_ipv4.c:1679
 sk_backlog_rcv include/net/sock.h:1020 [inline]
 __release_sock+0x134/0x3b0 net/core/sock.c:2550
 release_sock+0x54/0x1b0 net/core/sock.c:3074
 tcp_sendmsg+0x36/0x40 net/ipv4/tcp.c:1458
 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:821
 sock_sendmsg_nosec net/socket.c:654 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:674
 sock_write_iter+0x289/0x3c0 net/socket.c:1001
 call_write_iter include/linux/fs.h:1977 [inline]
 new_sync_write+0x426/0x650 fs/read_write.c:518
 vfs_write+0x796/0xa30 fs/read_write.c:605
 ksys_write+0x1ee/0x250 fs/read_write.c:658
 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

The buggy address belongs to the object at ffff8880734ff0c0
 which belongs to the cache skbuff_fclone_cache of size 472
The buggy address is located 32 bytes to the left of
 472-byte region [ffff8880734ff0c0, ffff8880734ff298)
The buggy address belongs to the page:
page:ffffea0001cd3fc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x734ff
flags: 0xfff00000000200(slab)
raw: 00fff00000000200 ffffea0001bbb908 ffffea000055fe08 ffff88801210af00
raw: 0000000000000000 ffff8880734ff0c0 0000000100000006 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880734fef80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880734ff000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880734ff080: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
                               ^
 ffff8880734ff100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880734ff180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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