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BUG: KCSAN: data-race in osq_lock / osq_lock

write to 0xffff88812bf2b054 of 4 bytes by task 17774 on cpu 1:
 osq_lock+0x89/0x2f0 kernel/locking/osq_lock.c:99
 rwsem_optimistic_spin+0x5f/0x320 kernel/locking/rwsem.c:800
 rwsem_down_write_slowpath+0x109/0x950 kernel/locking/rwsem.c:1150
 __down_write kernel/locking/rwsem.c:1392 [inline]
 down_write+0x88/0x90 kernel/locking/rwsem.c:1535
 lock_anon_vma_root mm/rmap.c:238 [inline]
 unlink_anon_vmas+0x13a/0x4b0 mm/rmap.c:388
 free_pgtables+0x147/0x200 mm/memory.c:395
 exit_mmap+0x151/0x300 mm/mmap.c:3162
 __mmput kernel/fork.c:1079 [inline]
 mmput+0xea/0x280 kernel/fork.c:1100
 exec_mmap fs/exec.c:1048 [inline]
 flush_old_exec+0x655/0xfd0 fs/exec.c:1281
 load_elf_binary+0x69a/0x2ec0 fs/binfmt_elf.c:847
 search_binary_handler fs/exec.c:1659 [inline]
 search_binary_handler+0x127/0x420 fs/exec.c:1636
 exec_binprm fs/exec.c:1702 [inline]
 __do_execve_file.isra.0+0xb76/0x11d0 fs/exec.c:1822
 do_execveat_common fs/exec.c:1868 [inline]
 do_execve fs/exec.c:1885 [inline]
 __do_sys_execve fs/exec.c:1961 [inline]
 __se_sys_execve fs/exec.c:1956 [inline]
 __x64_sys_execve+0x62/0x80 fs/exec.c:1956
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290

read to 0xffff88812bf2b054 of 4 bytes by task 17827 on cpu 0:
 osq_lock+0x170/0x2f0 kernel/locking/osq_lock.c:143
 rwsem_optimistic_spin+0x5f/0x320 kernel/locking/rwsem.c:800
 rwsem_down_write_slowpath+0x109/0x950 kernel/locking/rwsem.c:1150
 __down_write kernel/locking/rwsem.c:1392 [inline]
 down_write+0x88/0x90 kernel/locking/rwsem.c:1535
 anon_vma_lock_write include/linux/rmap.h:120 [inline]
 anon_vma_free mm/rmap.c:120 [inline]
 __put_anon_vma+0x14e/0x1a0 mm/rmap.c:1770
 put_anon_vma include/linux/rmap.h:115 [inline]
 unlink_anon_vmas+0x420/0x4b0 mm/rmap.c:416
 free_pgtables+0x147/0x200 mm/memory.c:395
 exit_mmap+0x151/0x300 mm/mmap.c:3162
 __mmput kernel/fork.c:1079 [inline]
 mmput+0xea/0x280 kernel/fork.c:1100
 exec_mmap fs/exec.c:1048 [inline]
 flush_old_exec+0x655/0xfd0 fs/exec.c:1281
 load_elf_binary+0x69a/0x2ec0 fs/binfmt_elf.c:847
 search_binary_handler fs/exec.c:1659 [inline]
 search_binary_handler+0x127/0x420 fs/exec.c:1636
 exec_binprm fs/exec.c:1702 [inline]
 __do_execve_file.isra.0+0xb76/0x11d0 fs/exec.c:1822

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 17827 Comm: udevd Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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