[moderation] [fs?] [mm?] KCSAN: data-race in filemap_fdatawrite_wbc / xas_clear_mark (4)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 0cac73eb3875 Merge tag 'pm-6.10-rc4' of git://git.kernel.o..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=147c73fe980000
kernel config: https://syzkaller.appspot.com/x/.config?x=68336ea4b6f4fc09
dashboard link: https://syzkaller.appspot.com/bug?extid=fc30ed4b106b4bd08f6b
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
CC: [ak...@linux-foundation.org linux-...@vger.kernel.org linux-...@vger.kernel.org linu...@kvack.org wi...@infradead.org]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/801ee0616f30/disk-0cac73eb.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/797930cdcbce/vmlinux-0cac73eb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/8aeca2684762/bzImage-0cac73eb.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+fc30ed...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in filemap_fdatawrite_wbc / xas_clear_mark

write to 0xffff888106aede0c of 4 bytes by task 10249 on cpu 1:
xa_mark_clear lib/xarray.c:77 [inline]
xas_clear_mark+0x169/0x180 lib/xarray.c:925
__folio_start_writeback+0x2e2/0x450 mm/page-writeback.c:3103
ext4_bio_write_folio+0x58b/0x9a0 fs/ext4/page-io.c:554
mpage_submit_folio fs/ext4/inode.c:1869 [inline]
mpage_map_and_submit_buffers fs/ext4/inode.c:2115 [inline]
mpage_map_and_submit_extent fs/ext4/inode.c:2254 [inline]
ext4_do_writepages+0x13a6/0x2110 fs/ext4/inode.c:2679
ext4_writepages+0x159/0x2e0 fs/ext4/inode.c:2768
do_writepages+0x1d8/0x480 mm/page-writeback.c:2634
filemap_fdatawrite_wbc+0xdb/0x100 mm/filemap.c:397
__filemap_fdatawrite_range mm/filemap.c:430 [inline]
file_write_and_wait_range+0xc8/0x170 mm/filemap.c:788
ext4_sync_file+0x134/0x6c0 fs/ext4/fsync.c:158
vfs_fsync_range+0x122/0x140 fs/sync.c:188
generic_write_sync include/linux/fs.h:2794 [inline]
ext4_buffered_write_iter+0x338/0x380 fs/ext4/file.c:305
ext4_file_write_iter+0x29f/0xe30
iter_file_splice_write+0x5e6/0x970 fs/splice.c:743
do_splice_from fs/splice.c:941 [inline]
direct_splice_actor+0x16c/0x2c0 fs/splice.c:1164
splice_direct_to_actor+0x305/0x670 fs/splice.c:1108
do_splice_direct_actor fs/splice.c:1207 [inline]
do_splice_direct+0xd7/0x150 fs/splice.c:1233
do_sendfile+0x3ab/0x960 fs/read_write.c:1295
__do_sys_sendfile64 fs/read_write.c:1362 [inline]
__se_sys_sendfile64 fs/read_write.c:1348 [inline]
__x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1348
x64_sys_call+0x2c9f/0x2d70 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 0xffff888106aede0c of 4 bytes by task 10250 on cpu 0:
xa_marked include/linux/xarray.h:424 [inline]
mapping_tagged include/linux/fs.h:498 [inline]
filemap_fdatawrite_wbc+0x5c/0x100 mm/filemap.c:393
__filemap_fdatawrite_range mm/filemap.c:430 [inline]
filemap_write_and_wait_range+0xb6/0x1f0 mm/filemap.c:685
kiocb_invalidate_pages+0x87/0x1e0 mm/filemap.c:2727
__iomap_dio_rw+0x585/0x1090 fs/iomap/direct-io.c:639
iomap_dio_rw+0x40/0x90 fs/iomap/direct-io.c:749
ext4_dio_write_iter fs/ext4/file.c:577 [inline]
ext4_file_write_iter+0xaa4/0xe30 fs/ext4/file.c:696
iter_file_splice_write+0x5e6/0x970 fs/splice.c:743
do_splice_from fs/splice.c:941 [inline]
direct_splice_actor+0x16c/0x2c0 fs/splice.c:1164
splice_direct_to_actor+0x305/0x670 fs/splice.c:1108
do_splice_direct_actor fs/splice.c:1207 [inline]
do_splice_direct+0xd7/0x150 fs/splice.c:1233
do_sendfile+0x3ab/0x960 fs/read_write.c:1295
__do_sys_sendfile64 fs/read_write.c:1362 [inline]
__se_sys_sendfile64 fs/read_write.c:1348 [inline]
__x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1348
x64_sys_call+0x2c9f/0x2d70 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: 0x0e000021 -> 0x04000021

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 10250 Comm: syz-executor.1 Not tainted 6.10.0-rc3-syzkaller-00109-g0cac73eb3875 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
==================================================================


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup