KCSAN: data-race in inode_update_timestamps / inode_update

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
upstream	KCSAN: data-race in inode_update_timestamps / inode_update_timestamps ext4				130	198d	302d	0/28	auto-obsoleted due to no activity on 2024/04/18 13:35
upstream	KCSAN: data-race in inode_update_timestamps / inode_update_timestamps (2) ext4				9	43d	143d	0/28	auto-obsoleted due to no activity on 2024/09/28 05:23

==================================================================
BUG: KCSAN: data-race in inode_update_timestamps / inode_update_timestamps

write to 0xffff88810b99ef74 of 4 bytes by task 29020 on cpu 0:
 inode_set_mtime_to_ts include/linux/fs.h:1644 [inline]
 inode_update_timestamps+0x166/0x280 fs/inode.c:1999
 generic_update_time fs/inode.c:2034 [inline]
 inode_update_time fs/inode.c:2054 [inline]
 __file_update_time fs/inode.c:2243 [inline]
 file_update_time+0x220/0x2b0 fs/inode.c:2273
 fault_dirty_shared_page+0xde/0x340 mm/memory.c:3204
 do_shared_fault mm/memory.c:5374 [inline]
 do_fault mm/memory.c:5420 [inline]
 do_pte_missing mm/memory.c:3965 [inline]
 handle_pte_fault mm/memory.c:5751 [inline]
 __handle_mm_fault mm/memory.c:5894 [inline]
 handle_mm_fault+0x1370/0x2a80 mm/memory.c:6062
 faultin_page mm/gup.c:1187 [inline]
 __get_user_pages+0xf2c/0x2670 mm/gup.c:1485
 __get_user_pages_locked mm/gup.c:1751 [inline]
 faultin_page_range+0x352/0x5d0 mm/gup.c:1975
 madvise_populate mm/madvise.c:943 [inline]
 do_madvise+0x3dc/0x2660 mm/madvise.c:1458
 __do_sys_madvise mm/madvise.c:1477 [inline]
 __se_sys_madvise mm/madvise.c:1475 [inline]
 __x64_sys_madvise+0x61/0x70 mm/madvise.c:1475
 x64_sys_call+0x2320/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:29
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff88810b99ef74 of 4 bytes by task 29019 on cpu 1:
 inode_get_mtime_nsec include/linux/fs.h:1630 [inline]
 inode_get_mtime include/linux/fs.h:1636 [inline]
 inode_update_timestamps+0x84/0x280 fs/inode.c:1993
 generic_update_time fs/inode.c:2034 [inline]
 inode_update_time fs/inode.c:2054 [inline]
 __file_update_time fs/inode.c:2243 [inline]
 file_update_time+0x220/0x2b0 fs/inode.c:2273
 fault_dirty_shared_page+0xde/0x340 mm/memory.c:3204
 do_shared_fault mm/memory.c:5374 [inline]
 do_fault mm/memory.c:5420 [inline]
 do_pte_missing mm/memory.c:3965 [inline]
 handle_pte_fault mm/memory.c:5751 [inline]
 __handle_mm_fault mm/memory.c:5894 [inline]
 handle_mm_fault+0x1370/0x2a80 mm/memory.c:6062
 do_user_addr_fault arch/x86/mm/fault.c:1338 [inline]
 handle_page_fault arch/x86/mm/fault.c:1481 [inline]
 exc_page_fault+0x3b9/0x650 arch/x86/mm/fault.c:1539
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623

value changed: 0x345ccbd6 -> 0x34f56256

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 29019 Comm: syz.2.6208 Tainted: G        W          6.12.0-rc1-syzkaller-00330-gfc20a3e57247 #0
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
==================================================================