syzbot

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BUG: KCSAN: data-race in inode_set_ctime_current / inode_update_timestamps

write to 0xffff8881047289a0 of 8 bytes by task 8196 on cpu 0:
 inode_set_ctime_current+0x533/0x770 fs/inode.c:2762
 inode_update_timestamps+0x84/0x270 fs/inode.c:2017
 generic_update_time fs/inode.c:2056 [inline]
 inode_update_time fs/inode.c:2076 [inline]
 __file_update_time fs/inode.c:2304 [inline]
 file_update_time+0x20e/0x2b0 fs/inode.c:2334
 fault_dirty_shared_page+0xd9/0x3c0 mm/memory.c:3403
 do_shared_fault mm/memory.c:5665 [inline]
 do_fault mm/memory.c:5711 [inline]
 do_pte_missing mm/memory.c:4234 [inline]
 handle_pte_fault mm/memory.c:6052 [inline]
 __handle_mm_fault mm/memory.c:6195 [inline]
 handle_mm_fault+0x165d/0x2c20 mm/memory.c:6364
 do_user_addr_fault+0x636/0x1090 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:623

read to 0xffff8881047289a0 of 8 bytes by task 8203 on cpu 1:
 inode_get_ctime_sec include/linux/fs.h:1747 [inline]
 inode_get_ctime include/linux/fs.h:1757 [inline]
 inode_update_timestamps+0x43/0x270 fs/inode.c:2014
 generic_update_time fs/inode.c:2056 [inline]
 inode_update_time fs/inode.c:2076 [inline]
 __file_update_time fs/inode.c:2304 [inline]
 file_update_time+0x20e/0x2b0 fs/inode.c:2334
 fault_dirty_shared_page+0xd9/0x3c0 mm/memory.c:3403
 do_shared_fault mm/memory.c:5665 [inline]
 do_fault mm/memory.c:5711 [inline]
 do_pte_missing mm/memory.c:4234 [inline]
 handle_pte_fault mm/memory.c:6052 [inline]
 __handle_mm_fault mm/memory.c:6195 [inline]
 handle_mm_fault+0x165d/0x2c20 mm/memory.c:6364
 do_user_addr_fault+0x3fe/0x1090 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:623
 __put_user_nocheck_4+0x3/0x10 arch/x86/lib/putuser.S:97
 ____sys_recvmsg+0x1a1/0x280 net/socket.c:2847
 ___sys_recvmsg+0x11f/0x370 net/socket.c:2876
 do_recvmmsg+0x1ef/0x540 net/socket.c:2971
 __sys_recvmmsg net/socket.c:3045 [inline]
 __do_sys_recvmmsg net/socket.c:3068 [inline]
 __se_sys_recvmmsg net/socket.c:3061 [inline]
 __x64_sys_recvmmsg+0xe5/0x170 net/socket.c:3061
 x64_sys_call+0x27a6/0x2ff0 arch/x86/include/generated/asm/syscalls_64.h:300
 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

value changed: 0x0000000068d7acff -> 0x0000000068d7ad00

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 8203 Comm: syz.3.1510 Not tainted syzkaller #0 PREEMPT(voluntary) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
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