KASAN: wild-memory-access Write in lock_sock_nested

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 2c746135 Linux 4.19.158
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=14bb2a39500000
kernel config: https://syzkaller.appspot.com/x/.config?x=c19abec6250dfe36
dashboard link: https://syzkaller.appspot.com/bug?extid=cab4f05aade48f603f73
compiler: gcc (GCC) 10.1.0-syz 20200507

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+cab4f0...@syzkaller.appspotmail.com

netlink: 168 bytes leftover after parsing attributes in process `syz-executor.4'.
net_ratelimit: 246 callbacks suppressed
TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters.
==================================================================
BUG: KASAN: wild-memory-access in atomic_inc include/asm-generic/atomic-instrumented.h:109 [inline]
BUG: KASAN: wild-memory-access in __lock_acquire+0x251/0x3ff0 kernel/locking/lockdep.c:3307
Write of size 4 at addr dead4ead00000138 by task syz-executor.0/13134

CPU: 0 PID: 13134 Comm: syz-executor.0 Not tainted 4.19.158-syzkaller #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+0x1fc/0x2fe lib/dump_stack.c:118
kasan_report_error.cold+0x15b/0x1c7 mm/kasan/report.c:352
kasan_report+0x8f/0x96 mm/kasan/report.c:412
atomic_inc include/asm-generic/atomic-instrumented.h:109 [inline]
__lock_acquire+0x251/0x3ff0 kernel/locking/lockdep.c:3307
lock_acquire+0x170/0x3c0 kernel/locking/lockdep.c:3907
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
_raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:168
spin_lock_bh include/linux/spinlock.h:334 [inline]
lock_sock_nested+0x3b/0x110 net/core/sock.c:2864
l2cap_sock_teardown_cb+0xa0/0x6d0 net/bluetooth/l2cap_sock.c:1340
l2cap_chan_del+0xbc/0xa50 net/bluetooth/l2cap_core.c:599
l2cap_conn_del+0x3a6/0x6e0 net/bluetooth/l2cap_core.c:1729
l2cap_disconn_cfm net/bluetooth/l2cap_core.c:7441 [inline]
l2cap_disconn_cfm+0x98/0xd0 net/bluetooth/l2cap_core.c:7434
hci_disconn_cfm include/net/bluetooth/hci_core.h:1261 [inline]
hci_conn_hash_flush+0x127/0x260 net/bluetooth/hci_conn.c:1512
hci_dev_do_close+0x659/0xf10 net/bluetooth/hci_core.c:1666
hci_unregister_dev+0x18b/0x910 net/bluetooth/hci_core.c:3271
vhci_release+0x70/0xe0 drivers/bluetooth/hci_vhci.c:354
__fput+0x2ce/0x890 fs/file_table.c:278
task_work_run+0x148/0x1c0 kernel/task_work.c:113
exit_task_work include/linux/task_work.h:22 [inline]
do_exit+0xbed/0x2be0 kernel/exit.c:890
do_group_exit+0x125/0x310 kernel/exit.c:993
get_signal+0x3f2/0x1f70 kernel/signal.c:2589
do_signal+0x8f/0x1670 arch/x86/kernel/signal.c:821
exit_to_usermode_loop+0x204/0x2a0 arch/x86/entry/common.c:163
prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45deb9
Code: 0d 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 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fdd068b1cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 000000000118bf28 RCX: 000000000045deb9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000118bf28
RBP: 000000000118bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c
R13: 00007ffc7a2fab2f R14: 00007fdd068b29c0 R15: 000000000118bf2c
==================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.