[moderation] [fs?] KCSAN: data-race in do_sendfile / do_sendfile (10)

Hello,

syzbot found the following issue on:

HEAD commit: f1b785f4c787 Merge tag 'for_linus' of git://git.kernel.org..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=10ade4c0580000
kernel config: https://syzkaller.appspot.com/x/.config?x=29fedde79f609854
dashboard link: https://syzkaller.appspot.com/bug?extid=be39254b0cdfa55a2579
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [[email protected] [email protected] [email protected] [email protected] [email protected]]

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/31ad73757710/disk-f1b785f4.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c70524c074ac/vmlinux-f1b785f4.xz
kernel image: https://storage.googleapis.com/syzbot-assets/467fef789d11/bzImage-f1b785f4.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email protected]

ext4 filesystem being mounted at /141/file0 supports timestamps until 2038-01-19 (0x7fffffff)
==================================================================
BUG: KCSAN: data-race in do_sendfile / do_sendfile

write to 0xffff8881168d51f0 of 8 bytes by task 5956 on cpu 0:
do_sendfile+0x76e/0x970
__do_sys_sendfile64 fs/read_write.c:1455 [inline]
__se_sys_sendfile64 fs/read_write.c:1441 [inline]
__x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1441
x64_sys_call+0xed5/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:41
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

write to 0xffff8881168d51f0 of 8 bytes by task 5950 on cpu 1:
do_sendfile+0x76e/0x970
__do_sys_sendfile64 fs/read_write.c:1455 [inline]
__se_sys_sendfile64 fs/read_write.c:1441 [inline]
__x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1441
x64_sys_call+0xed5/0x2d60 arch/x86/include/generated/asm/syscalls_64.h:41
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

value changed: 0x0000000000000000 -> 0x00000000000002e2

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 5950 Comm: syz.1.717 Not tainted 6.12.0-rc7-syzkaller-00042-gf1b785f4c787 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
==================================================================


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