syzbot

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BUG: KCSAN: data-race in l2tp_tunnel_del_work / sk_common_release

write to 0xffff88810413e5e0 of 8 bytes by task 3731 on cpu 1:
 sk_set_socket include/net/sock.h:1982 [inline]
 sock_orphan include/net/sock.h:2001 [inline]
 sk_common_release+0xda/0x250 net/core/sock.c:3769
 udp_lib_close+0x15/0x20 include/net/udp.h:199
 inet_release+0xce/0xf0 net/ipv4/af_inet.c:437
 inet6_release+0x3e/0x60 net/ipv6/af_inet6.c:489
 __sock_release net/socket.c:659 [inline]
 sock_close+0x68/0x150 net/socket.c:1421
 __fput+0x192/0x6f0 fs/file_table.c:422
 ____fput+0x15/0x20 fs/file_table.c:450
 task_work_run+0x13a/0x1a0 kernel/task_work.c:228
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xbe/0x130 kernel/entry/common.c:218
 do_syscall_64+0xd6/0x1c0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88810413e5e0 of 8 bytes by task 50 on cpu 0:
 l2tp_tunnel_del_work+0x33/0x2b0 net/l2tp/l2tp_core.c:1343
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0x483/0x9a0 kernel/workqueue.c:3312
 worker_thread+0x526/0x6e0 kernel/workqueue.c:3389
 kthread+0x1d1/0x210 kernel/kthread.c:389
 ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

value changed: 0xffff8881065a6d80 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 50 Comm: kworker/u8:3 Not tainted 6.11.0-rc6-syzkaller-00308-gb31c44928842 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Workqueue: l2tp l2tp_tunnel_del_work
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