[moderation] [ext4?] KCSAN: data-race in __mark_inode_dirty / __writeback_single_inode (3)

Hello,

syzbot found the following issue on:

HEAD commit: f23aa4c0761a Merge tag 'hid-for-linus-2024090201' of git:/..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17058b9f980000
kernel config: https://syzkaller.appspot.com/x/.config?x=95098faba89c70c9
dashboard link: https://syzkaller.appspot.com/bug?extid=ca4c8e8defb77349c38a
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [[email protected] [email protected] [email protected] [email protected]]

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

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vmlinux: https://storage.googleapis.com/syzbot-assets/acacebac526d/vmlinux-f23aa4c0.xz
kernel image: https://storage.googleapis.com/syzbot-assets/512566ea4d6d/bzImage-f23aa4c0.xz

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

EXT4-fs (loop2): mounted filesystem 00000000-0000-0000-0000-000000000000 r/w without journal. Quota mode: writeback.
==================================================================
BUG: KCSAN: data-race in __mark_inode_dirty / __writeback_single_inode

read-write to 0xffff888106297338 of 4 bytes by task 4762 on cpu 0:
__writeback_single_inode+0x1f4/0x850 fs/fs-writeback.c:1694
writeback_single_inode+0x16c/0x3f0 fs/fs-writeback.c:1779
sync_inode_metadata+0x5c/0x90 fs/fs-writeback.c:2849
generic_buffers_fsync_noflush+0xd8/0x120 fs/buffer.c:610
ext4_fsync_nojournal fs/ext4/fsync.c:88 [inline]
ext4_sync_file+0x1ff/0x6c0 fs/ext4/fsync.c:151
vfs_fsync_range+0x116/0x130 fs/sync.c:188
generic_write_sync include/linux/fs.h:2871 [inline]
ext4_buffered_write_iter+0x326/0x370 fs/ext4/file.c:305
ext4_file_write_iter+0x293/0xe10
iter_file_splice_write+0x5f1/0x980 fs/splice.c:743
do_splice_from fs/splice.c:941 [inline]
direct_splice_actor+0x160/0x2c0 fs/splice.c:1164
splice_direct_to_actor+0x302/0x670 fs/splice.c:1108
do_splice_direct_actor fs/splice.c:1207 [inline]
do_splice_direct+0xd7/0x150 fs/splice.c:1233
do_sendfile+0x39b/0x970 fs/read_write.c:1388
__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

read to 0xffff888106297338 of 4 bytes by task 4759 on cpu 1:
__mark_inode_dirty+0x198/0x7e0 fs/fs-writeback.c:2515
generic_update_time fs/inode.c:2041 [inline]
inode_update_time fs/inode.c:2054 [inline]
touch_atime+0x230/0x350 fs/inode.c:2126
file_accessed include/linux/fs.h:2528 [inline]
filemap_splice_read+0x8a5/0x910 mm/filemap.c:2977
ext4_file_splice_read+0x8f/0xb0 fs/ext4/file.c:158
do_splice_read fs/splice.c:985 [inline]
splice_direct_to_actor+0x269/0x670 fs/splice.c:1089
do_splice_direct_actor fs/splice.c:1207 [inline]
do_splice_direct+0xd7/0x150 fs/splice.c:1233
do_sendfile+0x39b/0x970 fs/read_write.c:1388
__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: 0x0000003a -> 0x00000002

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 4759 Comm: syz.2.502 Not tainted 6.12.0-rc1-syzkaller-00042-gf23aa4c0761a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
==================================================================


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