syzbot

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BUG: KCSAN: data-race in generic_permission / setattr_copy

write to 0xffff888108a4c850 of 2 bytes by task 19 on cpu 0:
 setattr_copy+0x1af/0x1c0 fs/attr.c:247
 shmem_setattr+0xb0/0x450 mm/shmem.c:1118
 notify_change+0x8a3/0xa80 fs/attr.c:398
 handle_remove drivers/base/devtmpfs.c:333 [inline]
 handle drivers/base/devtmpfs.c:382 [inline]
 devtmpfs_work_loop+0x783/0x8d0 drivers/base/devtmpfs.c:395
 devtmpfsd+0x3f/0x40 drivers/base/devtmpfs.c:437
 kthread+0x262/0x280 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

read to 0xffff888108a4c850 of 2 bytes by task 9254 on cpu 1:
 acl_permission_check fs/namei.c:326 [inline]
 generic_permission+0x24/0x420 fs/namei.c:392
 do_inode_permission fs/namei.c:453 [inline]
 inode_permission+0x6b/0x290 fs/namei.c:513
 may_open+0x1a7/0x2f0 fs/namei.c:2995
 do_open fs/namei.c:3372 [inline]
 path_openat+0x16ec/0x1f20 fs/namei.c:3507
 do_filp_open+0xe9/0x200 fs/namei.c:3534
 do_sys_openat2+0xa3/0x250 fs/open.c:1204
 do_sys_open fs/open.c:1220 [inline]
 __do_sys_open fs/open.c:1228 [inline]
 __se_sys_open fs/open.c:1224 [inline]
 __x64_sys_open+0xe2/0x110 fs/open.c:1224
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x6180 -> 0x6000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 9254 Comm: systemd-udevd Not tainted 5.14.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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