syzbot

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BUG: KCSAN: data-race in file_update_time / inode_set_ctime_to_ts

write to 0xffff8881004bb888 of 4 bytes by task 21509 on cpu 1:
 inode_set_ctime_to_ts+0x84/0x170 fs/inode.c:2727
 inode_set_ctime_current+0x1d6/0x770 fs/inode.c:2790
 inode_update_timestamps+0x84/0x270 fs/inode.c:2071
 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
 faultin_page mm/gup.c:1126 [inline]
 __get_user_pages+0x102a/0x1ed0 mm/gup.c:1428
 __get_user_pages_locked mm/gup.c:1692 [inline]
 __gup_longterm_locked+0x8ef/0xe60 mm/gup.c:2476
 pin_user_pages_remote+0x7e/0xb0 mm/gup.c:3363
 process_vm_rw_single_vec mm/process_vm_access.c:106 [inline]
 process_vm_rw_core mm/process_vm_access.c:216 [inline]
 process_vm_rw+0x484/0x960 mm/process_vm_access.c:284
 __do_sys_process_vm_writev mm/process_vm_access.c:304 [inline]
 __se_sys_process_vm_writev mm/process_vm_access.c:299 [inline]
 __x64_sys_process_vm_writev+0x78/0x90 mm/process_vm_access.c:299
 x64_sys_call+0x2a80/0x3000 arch/x86/include/generated/asm/syscalls_64.h:312
 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 0xffff8881004bb888 of 4 bytes by task 21512 on cpu 0:
 inode_get_ctime_nsec include/linux/fs.h:1869 [inline]
 inode_get_ctime include/linux/fs.h:1875 [inline]
 inode_needs_update_time fs/inode.c:2340 [inline]
 file_update_time+0xec/0x2b0 fs/inode.c:2383
 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
 faultin_page mm/gup.c:1126 [inline]
 __get_user_pages+0x102a/0x1ed0 mm/gup.c:1428
 __get_user_pages_locked mm/gup.c:1692 [inline]
 __gup_longterm_locked+0x2fb/0xe60 mm/gup.c:2481
 gup_fast_fallback+0x1f5/0x1420 mm/gup.c:3220
 pin_user_pages_fast+0x5f/0x90 mm/gup.c:3326
 io_pin_pages+0xba/0x170 io_uring/memmap.c:63
 io_sqe_buffer_register+0x184/0x1430 io_uring/rsrc.c:799
 io_sqe_buffers_register+0x2b1/0x540 io_uring/rsrc.c:914
 __io_uring_register io_uring/register.c:649 [inline]
 __do_sys_io_uring_register io_uring/register.c:928 [inline]
 __se_sys_io_uring_register+0x90e/0xf00 io_uring/register.c:905
 __x64_sys_io_uring_register+0x55/0x70 io_uring/register.c:905
 x64_sys_call+0x18a3/0x3000 arch/x86/include/generated/asm/syscalls_64.h:428
 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: 0x030ea2e0 -> 0x03a73962

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 UID: 0 PID: 21512 Comm: syz.1.10896 Tainted: G        W           syzkaller #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
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