KCSAN: data-race in inode_update_timestamps / inode_update

Kernel	Title	Rank 🛈	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in inode_update_timestamps / inode_update_timestamps ext4	6	130	665d	768d	0/29	auto-obsoleted due to no activity on 2024/04/18 13:35
upstream	KCSAN: data-race in inode_update_timestamps / inode_update_timestamps (4) fs	6	1	185d	185d	0/29	auto-obsoleted due to no activity on 2025/09/08 10:05
upstream	KCSAN: data-race in inode_update_timestamps / inode_update_timestamps (3) fs	6	9	313d	466d	0/29	auto-obsoleted due to no activity on 2025/05/03 00:27
upstream	KCSAN: data-race in inode_update_timestamps / inode_update_timestamps (2) ext4	6	9	509d	610d	0/29	auto-obsoleted due to no activity on 2024/09/28 05:23

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BUG: KCSAN: data-race in inode_update_timestamps / inode_update_timestamps

write to 0xffff888104e529a4 of 4 bytes by task 2408 on cpu 0:
 inode_set_mtime_to_ts include/linux/fs.h:1839 [inline]
 inode_update_timestamps+0x147/0x270 fs/inode.c:2075
 generic_update_time fs/inode.c:2110 [inline]
 inode_update_time fs/inode.c:2130 [inline]
 __file_update_time fs/inode.c:2357 [inline]
 file_update_time+0x20e/0x2b0 fs/inode.c:2387
 fault_dirty_shared_page+0xd9/0x3c0 mm/memory.c:3531
 do_shared_fault mm/memory.c:5808 [inline]
 do_fault mm/memory.c:5854 [inline]
 do_pte_missing mm/memory.c:4362 [inline]
 handle_pte_fault mm/memory.c:6195 [inline]
 __handle_mm_fault mm/memory.c:6336 [inline]
 handle_mm_fault+0x165d/0x2be0 mm/memory.c:6505
 do_user_addr_fault+0x3fe/0x1080 arch/x86/mm/fault.c:1387
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x62/0xa0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
 rep_movs_alternative+0x4a/0x90 arch/x86/lib/copy_user_64.S:68
 copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline]
 raw_copy_to_user arch/x86/include/asm/uaccess_64.h:147 [inline]
 _inline_copy_to_user include/linux/uaccess.h:197 [inline]
 _copy_to_user+0x7c/0xa0 lib/usercopy.c:26
 copy_to_user include/linux/uaccess.h:225 [inline]
 pagemap_read+0x379/0x5e0 fs/proc/task_mmu.c:2254
 vfs_read+0x1a8/0x770 fs/read_write.c:570
 ksys_pread64 fs/read_write.c:763 [inline]
 __do_sys_pread64 fs/read_write.c:771 [inline]
 __se_sys_pread64 fs/read_write.c:768 [inline]
 __x64_sys_pread64+0xfd/0x150 fs/read_write.c:768
 x64_sys_call+0x29e6/0x3000 arch/x86/include/generated/asm/syscalls_64.h:18
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xd2/0x200 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888104e529a4 of 4 bytes by task 2407 on cpu 1:
 inode_get_mtime_nsec include/linux/fs.h:1825 [inline]
 inode_get_mtime include/linux/fs.h:1831 [inline]
 inode_update_timestamps+0x74/0x270 fs/inode.c:2069
 generic_update_time fs/inode.c:2110 [inline]
 inode_update_time fs/inode.c:2130 [inline]
 __file_update_time fs/inode.c:2357 [inline]
 file_update_time+0x20e/0x2b0 fs/inode.c:2387
 fault_dirty_shared_page+0xd9/0x3c0 mm/memory.c:3531
 do_shared_fault mm/memory.c:5808 [inline]
 do_fault mm/memory.c:5854 [inline]
 do_pte_missing mm/memory.c:4362 [inline]
 handle_pte_fault mm/memory.c:6195 [inline]
 __handle_mm_fault mm/memory.c:6336 [inline]
 handle_mm_fault+0x165d/0x2be0 mm/memory.c:6505
 do_user_addr_fault+0x630/0x1080 arch/x86/mm/fault.c:1336
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x62/0xa0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618

value changed: 0x36a7a38f -> 0x37c5231d

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 2407 Comm: syz.5.21554 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
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