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

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 0dd3ee311255 Linux 6.7
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16095deee80000
kernel config: https://syzkaller.appspot.com/x/.config?x=1bb2daade28c90a5
dashboard link: https://syzkaller.appspot.com/bug?extid=9a0e715c8fb872a77970
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/b3bdaecbc4f5/disk-0dd3ee31.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/6656b77ef58a/vmlinux-0dd3ee31.xz
kernel image: https://storage.googleapis.com/syzbot-assets/85fa7f08c720/bzImage-0dd3ee31.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9a0e71...@syzkaller.appspotmail.com

==================================================================
BUG: KCSAN: data-race in __filemap_add_folio / file_write_and_wait_range

read-write to 0xffff8881069df528 of 8 bytes by task 9771 on cpu 0:
__filemap_add_folio+0x4c1/0x730 mm/filemap.c:902
filemap_add_folio+0x70/0x160 mm/filemap.c:937
page_cache_ra_unbounded+0x15e/0x2e0 mm/readahead.c:250
do_page_cache_ra mm/readahead.c:299 [inline]
page_cache_ra_order mm/readahead.c:546 [inline]
ondemand_readahead+0x524/0x690 mm/readahead.c:668
page_cache_sync_ra+0x27e/0x2a0 mm/readahead.c:695
page_cache_sync_readahead include/linux/pagemap.h:1283 [inline]
filemap_get_pages+0x251/0xf90 mm/filemap.c:2497
filemap_splice_read+0x238/0x7f0 mm/filemap.c:2869
ext4_file_splice_read+0x95/0xb0 fs/ext4/file.c:158
vfs_splice_read fs/splice.c:993 [inline]
splice_direct_to_actor+0x28c/0x690 fs/splice.c:1069
do_splice_direct+0x10d/0x190 fs/splice.c:1194
do_sendfile+0x3c4/0x980 fs/read_write.c:1254
__do_sys_sendfile64 fs/read_write.c:1322 [inline]
__se_sys_sendfile64 fs/read_write.c:1308 [inline]
__x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1308
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff8881069df528 of 8 bytes by task 9757 on cpu 1:
mapping_needs_writeback mm/filemap.c:625 [inline]
file_write_and_wait_range+0x67/0x190 mm/filemap.c:777
ext4_sync_file+0x133/0x6c0 fs/ext4/fsync.c:158
vfs_fsync_range+0x111/0x120 fs/sync.c:188
generic_write_sync include/linux/fs.h:2653 [inline]
iomap_dio_complete+0x36a/0x4c0 fs/iomap/direct-io.c:126
iomap_dio_rw+0x62/0x90 fs/iomap/direct-io.c:752
ext4_dio_write_iter fs/ext4/file.c:577 [inline]
ext4_file_write_iter+0xa8a/0xe10 fs/ext4/file.c:696
do_iter_write+0x4ad/0x770 fs/read_write.c:860
vfs_iter_write+0x56/0x70 fs/read_write.c:901
iter_file_splice_write+0x462/0x7e0 fs/splice.c:736
do_splice_from fs/splice.c:933 [inline]
direct_splice_actor+0x8a/0xb0 fs/splice.c:1142
splice_direct_to_actor+0x31d/0x690 fs/splice.c:1088
do_splice_direct+0x10d/0x190 fs/splice.c:1194
do_sendfile+0x3c4/0x980 fs/read_write.c:1254
__do_sys_sendfile64 fs/read_write.c:1322 [inline]
__se_sys_sendfile64 fs/read_write.c:1308 [inline]
__x64_sys_sendfile64+0x110/0x150 fs/read_write.c:1308
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x00000000000000a6 -> 0x00000000000000a8

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 9757 Comm: syz-executor.4 Not tainted 6.7.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
==================================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.