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KCSAN: data-race in __filemap_add_folio / file_write_and_wait_range (4)

Status: auto-obsoleted due to no activity on 2024/02/11 21:27
Subsystems: fs mm
[Documentation on labels]
Reported-by: syzbot+9a0e715c8fb872a77970@syzkaller.appspotmail.com
First crash: 141d, last: 140d
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __filemap_add_folio / file_write_and_wait_range (5) mm 7 22d 96d 0/26 moderation: reported on 2024/02/21 10:43
upstream KCSAN: data-race in __filemap_add_folio / file_write_and_wait_range mm 90 401d 929d 0/26 auto-obsoleted due to no activity on 2023/05/27 02:10
upstream KCSAN: data-race in __filemap_add_folio / file_write_and_wait_range (3) mm 4 181d 169d 0/26 auto-obsoleted due to no activity on 2024/01/02 05:06
upstream KCSAN: data-race in __filemap_add_folio / file_write_and_wait_range (2) ext4 4 269d 279d 0/26 auto-obsoleted due to no activity on 2023/10/06 06:01

Sample crash report:
==================================================================
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
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/01/07 21:26 upstream 0dd3ee311255 d0304e9c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_add_folio / file_write_and_wait_range
2024/01/06 13:17 upstream 95c8a35f1c01 d0304e9c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in __filemap_add_folio / file_write_and_wait_range
* Struck through repros no longer work on HEAD.