syzbot

==================================================================
BUG: KCSAN: data-race in fasync_remove_entry / sock_wake_async

write to 0xffff88810697b458 of 8 bytes by task 4477 on cpu 1:
 fasync_remove_entry+0xd2/0x130 fs/fcntl.c:1008
 fasync_helper+0x96/0xc0 fs/fcntl.c:1107
 sock_fasync+0x5a/0xc0 net/socket.c:1451
 __fput+0x664/0x6d0 fs/file_table.c:428
 ____fput+0x1c/0x30 fs/file_table.c:459
 task_work_run+0x13a/0x1a0 kernel/task_work.c:239
 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 0xffff88810697b458 of 8 bytes by task 4475 on cpu 0:
 sock_wake_async+0x2a/0x120 net/socket.c:1466
 sk_wake_async_rcu include/net/sock.h:2452 [inline]
 unix_write_space+0x135/0x140 net/unix/af_unix.c:618
 sock_wfree+0x147/0x3b0 net/core/sock.c:2571
 unix_destruct_scm+0xc5/0xf0 net/unix/af_unix.c:1884
 skb_release_head_state+0xbb/0x1b0 net/core/skbuff.c:1177
 skb_release_all net/core/skbuff.c:1188 [inline]
 __kfree_skb+0x16/0x150 net/core/skbuff.c:1204
 sk_skb_reason_drop+0xba/0x290 net/core/skbuff.c:1242
 kfree_skb_reason include/linux/skbuff.h:1262 [inline]
 kfree_skb include/linux/skbuff.h:1271 [inline]
 unix_release_sock+0x603/0x750 net/unix/af_unix.c:724
 unix_release+0x57/0x80 net/unix/af_unix.c:1109
 __sock_release net/socket.c:658 [inline]
 sock_close+0x68/0x150 net/socket.c:1426
 __fput+0x17a/0x6d0 fs/file_table.c:431
 ____fput+0x1c/0x30 fs/file_table.c:459
 task_work_run+0x13a/0x1a0 kernel/task_work.c:239
 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

value changed: 0xffff8881123785a0 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 4475 Comm: syz.3.399 Not tainted 6.12.0-rc5-syzkaller-00044-gc1e939a21eb1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
==================================================================