syzbot

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BUG: KCSAN: data-race in pipe_release / wait_for_partner

read-write to 0xffff888048418070 of 4 bytes by task 2860 on cpu 0:
 put_pipe_info fs/pipe.c:688 [inline]
 pipe_release+0x164/0x1c0 fs/pipe.c:718
 __fput+0x243/0x4d0 fs/file_table.c:281
 ____fput+0x11/0x20 fs/file_table.c:314
 task_work_run+0x8e/0x110 kernel/task_work.c:151
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:164 [inline]
 exit_to_user_mode_prepare+0x13c/0x170 kernel/entry/common.c:191
 syscall_exit_to_user_mode+0x16/0x30 kernel/entry/common.c:266
 do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888048418070 of 4 bytes by task 2851 on cpu 1:
 pipe_lock_nested fs/pipe.c:65 [inline]
 pipe_lock fs/pipe.c:74 [inline]
 wait_for_partner+0xdd/0x1a0 fs/pipe.c:1063
 fifo_open+0x4c8/0x5d0 fs/pipe.c:1151
 do_dentry_open+0x520/0x870 fs/open.c:817
 vfs_open+0x43/0x50 fs/open.c:931
 do_open fs/namei.c:3252 [inline]
 path_openat+0x1844/0x20a0 fs/namei.c:3369
 do_filp_open+0xbd/0x1d0 fs/namei.c:3396
 do_sys_openat2+0xa3/0x240 fs/open.c:1168
 do_sys_open fs/open.c:1184 [inline]
 __do_sys_openat fs/open.c:1200 [inline]
 __se_sys_openat fs/open.c:1195 [inline]
 __x64_sys_openat+0xef/0x110 fs/open.c:1195
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 2851 Comm: syz-executor.3 Not tainted 5.9.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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