syzbot

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BUG: KCSAN: data-race in fuse_abort_conn / fuse_get_req

read to 0xffff88812678c928 of 4 bytes by task 15793 on cpu 0:
 fuse_get_req+0x18a/0x450 fs/fuse/dev.c:121
 fuse_simple_request+0x7f/0x640 fs/fuse/dev.c:492
 fuse_do_getattr+0x1e5/0x850 fs/fuse/dir.c:943
 fuse_perm_getattr+0x46/0x70 fs/fuse/dir.c:1126
 fuse_permission+0x224/0x390 fs/fuse/dir.c:1163
 do_inode_permission fs/namei.c:384 [inline]
 inode_permission+0x241/0x3c0 fs/namei.c:449
 may_lookup fs/namei.c:1694 [inline]
 link_path_walk.part.0+0x622/0xa90 fs/namei.c:2074
 link_path_walk fs/namei.c:2259 [inline]
 path_lookupat.isra.0+0x77/0x5a0 fs/namei.c:2307
 filename_lookup+0x145/0x2b0 fs/namei.c:2338
 user_path_at_empty+0x4c/0x70 fs/namei.c:2598
 user_path_at include/linux/namei.h:49 [inline]
 user_statfs+0x55/0xf0 fs/statfs.c:101
 __do_sys_statfs+0x3f/0xa0 fs/statfs.c:193
 __se_sys_statfs fs/statfs.c:190 [inline]
 __x64_sys_statfs+0x3a/0x50 fs/statfs.c:190
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff88812678c928 of 4 bytes by task 15791 on cpu 1:
 fuse_abort_conn+0xa9/0x740 fs/fuse/dev.c:2101
 fuse_dev_release+0x26b/0x290 fs/fuse/dev.c:2181
 __fput+0x1e1/0x520 fs/file_table.c:280
 ____fput+0x1f/0x30 fs/file_table.c:313
 task_work_run+0xf6/0x130 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x2b4/0x2c0 arch/x86/entry/common.c:163
 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:274 [inline]
 do_syscall_64+0x353/0x370 arch/x86/entry/common.c:300
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 15791 Comm: syz-executor.1 Not tainted 5.4.0-rc6+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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