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

write to 0xffff888119767828 of 4 bytes by task 2226 on cpu 0:
 inode_set_atime_to_ts include/linux/fs.h:1672 [inline]
 inode_update_timestamps fs/inode.c:2035 [inline]
 generic_update_time fs/inode.c:2057 [inline]
 inode_update_time fs/inode.c:2077 [inline]
 touch_atime+0x1f3/0x350 fs/inode.c:2149
 file_accessed include/linux/fs.h:2599 [inline]
 shmem_file_splice_read+0x584/0x5d0 mm/shmem.c:3623
 do_splice_read fs/splice.c:979 [inline]
 splice_direct_to_actor+0x26c/0x680 fs/splice.c:1083
 do_splice_direct_actor fs/splice.c:1201 [inline]
 do_splice_direct+0xd9/0x150 fs/splice.c:1227
 do_sendfile+0x40a/0x690 fs/read_write.c:1368
 __do_sys_sendfile64 fs/read_write.c:1429 [inline]
 __se_sys_sendfile64 fs/read_write.c:1415 [inline]
 __x64_sys_sendfile64+0x113/0x160 fs/read_write.c:1415
 x64_sys_call+0xfc3/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

read to 0xffff888119767828 of 4 bytes by task 2230 on cpu 1:
 inode_get_atime_nsec include/linux/fs.h:1657 [inline]
 inode_get_atime include/linux/fs.h:1663 [inline]
 inode_update_timestamps fs/inode.c:2032 [inline]
 generic_update_time fs/inode.c:2057 [inline]
 inode_update_time fs/inode.c:2077 [inline]
 touch_atime+0x1a0/0x350 fs/inode.c:2149
 file_accessed include/linux/fs.h:2599 [inline]
 shmem_file_splice_read+0x584/0x5d0 mm/shmem.c:3623
 do_splice_read fs/splice.c:979 [inline]
 splice_direct_to_actor+0x26c/0x680 fs/splice.c:1083
 do_splice_direct_actor fs/splice.c:1201 [inline]
 do_splice_direct+0xd9/0x150 fs/splice.c:1227
 do_sendfile+0x40a/0x690 fs/read_write.c:1368
 __do_sys_sendfile64 fs/read_write.c:1429 [inline]
 __se_sys_sendfile64 fs/read_write.c:1415 [inline]
 __x64_sys_sendfile64+0x113/0x160 fs/read_write.c:1415
 x64_sys_call+0xfc3/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x39dcd975 -> 0x3a756ff6

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 2230 Comm: syz.3.10469 Tainted: G        W           6.14.0-syzkaller-12456-gacc4d5ff0b61 #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
==================================================================
==================================================================
BUG: KCSAN: data-race in shmem_file_splice_read / shmem_file_splice_read

write to 0xffff88812e9e1be8 of 8 bytes by task 2226 on cpu 0:
 shmem_file_splice_read+0x446/0x5d0 mm/shmem.c:3613
 do_splice_read fs/splice.c:979 [inline]
 splice_direct_to_actor+0x26c/0x680 fs/splice.c:1083
 do_splice_direct_actor fs/splice.c:1201 [inline]
 do_splice_direct+0xd9/0x150 fs/splice.c:1227
 do_sendfile+0x40a/0x690 fs/read_write.c:1368
 __do_sys_sendfile64 fs/read_write.c:1429 [inline]
 __se_sys_sendfile64 fs/read_write.c:1415 [inline]
 __x64_sys_sendfile64+0x113/0x160 fs/read_write.c:1415
 x64_sys_call+0xfc3/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

write to 0xffff88812e9e1be8 of 8 bytes by task 2230 on cpu 1:
 shmem_file_splice_read+0x446/0x5d0 mm/shmem.c:3613
 do_splice_read fs/splice.c:979 [inline]
 splice_direct_to_actor+0x26c/0x680 fs/splice.c:1083
 do_splice_direct_actor fs/splice.c:1201 [inline]
 do_splice_direct+0xd9/0x150 fs/splice.c:1227
 do_sendfile+0x40a/0x690 fs/read_write.c:1368
 __do_sys_sendfile64 fs/read_write.c:1429 [inline]
 __se_sys_sendfile64 fs/read_write.c:1415 [inline]
 __x64_sys_sendfile64+0x113/0x160 fs/read_write.c:1415
 x64_sys_call+0xfc3/0x2e10 arch/x86/include/generated/asm/syscalls_64.h:41
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xc9/0x1c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x000000000000499b -> 0x00000000000049a1

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 2230 Comm: syz.3.10469 Tainted: G        W           6.14.0-syzkaller-12456-gacc4d5ff0b61 #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
==================================================================