[moderation] [fs?] [mm?] KCSAN: data-race in __filemap_add_folio / file_write_and_wait_range (5)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 9fc1ccccfd8d Merge tag 'for-linus' of git://git.kernel.org..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=171dda8a180000
kernel config: https://syzkaller.appspot.com/x/.config?x=7507056e4ee79a
dashboard link: https://syzkaller.appspot.com/bug?extid=5cba2f11c9c99940ec99
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/1bf15664392d/disk-9fc1cccc.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8837faed4eb2/vmlinux-9fc1cccc.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a039dd33931a/bzImage-9fc1cccc.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5cba2f...@syzkaller.appspotmail.com

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

read-write to 0xffff888106c0b528 of 8 bytes by task 5204 on cpu 1:
__filemap_add_folio+0x4c1/0x730 mm/filemap.c:903
filemap_add_folio+0x70/0x160 mm/filemap.c:938
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:544 [inline]
ondemand_readahead+0x50b/0x670 mm/readahead.c:666
page_cache_sync_ra+0x27e/0x2a0 mm/readahead.c:693
page_cache_sync_readahead include/linux/pagemap.h:1300 [inline]
filemap_get_pages+0x251/0xf90 mm/filemap.c:2498
filemap_splice_read+0x337/0x8f0 mm/filemap.c:2872
ext4_file_splice_read+0x95/0xb0 fs/ext4/file.c:158
do_splice_read fs/splice.c:985 [inline]
splice_direct_to_actor+0x268/0x660 fs/splice.c:1089
do_splice_direct_actor fs/splice.c:1207 [inline]
do_splice_direct+0xd7/0x150 fs/splice.c:1233
do_sendfile+0x3b9/0x960 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
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

read to 0xffff888106c0b528 of 8 bytes by task 5205 on cpu 0:
mapping_needs_writeback mm/filemap.c:626 [inline]
file_write_and_wait_range+0x67/0x190 mm/filemap.c:778
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:2732 [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
call_write_iter include/linux/fs.h:2085 [inline]
iter_file_splice_write+0x5de/0x950 fs/splice.c:743
do_splice_from fs/splice.c:941 [inline]
direct_splice_actor+0x167/0x2c0 fs/splice.c:1164
splice_direct_to_actor+0x2fb/0x660 fs/splice.c:1108
do_splice_direct_actor fs/splice.c:1207 [inline]
do_splice_direct+0xd7/0x150 fs/splice.c:1233
do_sendfile+0x3b9/0x960 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
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x1d0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

value changed: 0x0000000000000343 -> 0x0000000000000346

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 5205 Comm: syz-executor.3 Not tainted 6.8.0-rc5-syzkaller-00020-g9fc1ccccfd8d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
==================================================================


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