syzbot


KCSAN: data-race in ext4_es_lookup_extent / ext4_es_lookup_extent (8)

Status: auto-closed as invalid on 2021/07/03 03:54
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 542d, last: 493d
similar bugs (8):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in ext4_es_lookup_extent / ext4_es_lookup_extent (4) 1 886d 886d 0/24 auto-closed as invalid on 2020/06/18 13:13
upstream KCSAN: data-race in ext4_es_lookup_extent / ext4_es_lookup_extent (5) 3 738d 795d 0/24 auto-closed as invalid on 2020/10/30 13:53
upstream KCSAN: data-race in ext4_es_lookup_extent / ext4_es_lookup_extent (6) 1 689d 665d 0/24 auto-closed as invalid on 2020/12/21 12:01
upstream KCSAN: data-race in ext4_es_lookup_extent / ext4_es_lookup_extent (3) 5 978d 1065d 0/24 auto-closed as invalid on 2020/04/09 02:07
upstream KCSAN: data-race in ext4_es_lookup_extent / ext4_es_lookup_extent (9) 4 326d 335d 0/24 auto-closed as invalid on 2021/12/17 02:26
upstream KCSAN: data-race in ext4_es_lookup_extent / ext4_es_lookup_extent (2) 1 1084d 1084d 0/24 closed as invalid on 2019/10/18 14:11
upstream KCSAN: data-race in ext4_es_lookup_extent / ext4_es_lookup_extent 60 1084d 1095d 0/24 closed as invalid on 2019/10/15 15:50
upstream KCSAN: data-race in ext4_es_lookup_extent / ext4_es_lookup_extent (7) 2 627d 648d 0/24 auto-closed as invalid on 2021/02/19 02:54

Sample crash report:
==================================================================
BUG: KCSAN: data-race in ext4_es_lookup_extent / ext4_es_lookup_extent

write to 0xffff8881065c82f0 of 8 bytes by task 7603 on cpu 1:
 ext4_es_set_referenced fs/ext4/extents_status.h:194 [inline]
 ext4_es_lookup_extent+0x2ec/0x490 fs/ext4/extents_status.c:968
 ext4_map_blocks+0xfd/0xef0 fs/ext4/inode.c:530
 ext4_mpage_readpages+0x6d9/0x1130 fs/ext4/readpage.c:304
 ext4_readahead+0x99/0xa0 fs/ext4/inode.c:3260
 read_pages+0x9f/0x530 mm/readahead.c:130
 page_cache_ra_unbounded+0x3c8/0x410 mm/readahead.c:238
 ondemand_readahead+0x579/0x7b0 mm/readahead.c:267
 page_cache_sync_ra+0xaf/0xe0 mm/readahead.c:578
 page_cache_sync_readahead include/linux/pagemap.h:879 [inline]
 filemap_get_pages mm/filemap.c:2467 [inline]
 filemap_read+0x388/0x1230 mm/filemap.c:2550
 generic_file_read_iter+0x75/0x2c0 mm/filemap.c:2701
 ext4_file_read_iter+0x1db/0x290 fs/ext4/file.c:73
 call_read_iter include/linux/fs.h:2108 [inline]
 generic_file_splice_read+0x22a/0x310 fs/splice.c:311
 do_splice_to fs/splice.c:796 [inline]
 splice_direct_to_actor+0x2aa/0x650 fs/splice.c:870
 do_splice_direct+0xf5/0x170 fs/splice.c:979
 do_sendfile+0x773/0xda0 fs/read_write.c:1260
 __do_sys_sendfile64 fs/read_write.c:1325 [inline]
 __se_sys_sendfile64 fs/read_write.c:1311 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1311
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881065c82f0 of 8 bytes by task 7593 on cpu 0:
 ext4_es_lookup_extent+0x29e/0x490 fs/ext4/extents_status.c:966
 ext4_map_blocks+0xfd/0xef0 fs/ext4/inode.c:530
 ext4_iomap_begin+0x1af/0x620 fs/ext4/inode.c:3472
 iomap_apply+0x8d/0x400 fs/iomap/apply.c:46
 __iomap_dio_rw+0x5af/0xad0 fs/iomap/direct-io.c:561
 iomap_dio_rw+0x30/0x70 fs/iomap/direct-io.c:649
 ext4_dio_write_iter fs/ext4/file.c:568 [inline]
 ext4_file_write_iter+0xa04/0x11d0 fs/ext4/file.c:678
 call_write_iter include/linux/fs.h:2114 [inline]
 do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740
 do_iter_write+0x112/0x4c0 fs/read_write.c:866
 vfs_iter_write+0x4c/0x70 fs/read_write.c:907
 iter_file_splice_write+0x40a/0x750 fs/splice.c:689
 do_splice_from fs/splice.c:767 [inline]
 direct_splice_actor+0x80/0xa0 fs/splice.c:936
 splice_direct_to_actor+0x345/0x650 fs/splice.c:891
 do_splice_direct+0xf5/0x170 fs/splice.c:979
 do_sendfile+0x773/0xda0 fs/read_write.c:1260
 __do_sys_sendfile64 fs/read_write.c:1325 [inline]
 __se_sys_sendfile64 fs/read_write.c:1311 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1311
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0800000000022a41 -> 0x8800000000022a41

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7593 Comm: syz-executor.4 Not tainted 5.13.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (6):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2021/05/29 03:49 upstream 5ff2756afde0 858ea628 .config log report info KCSAN: data-race in ext4_es_lookup_extent / ext4_es_lookup_extent
ci2-upstream-kcsan-gce 2021/05/17 18:30 upstream d07f6ca923ea a2eb125d .config log report info KCSAN: data-race in ext4_es_lookup_extent / ext4_es_lookup_extent
ci2-upstream-kcsan-gce 2021/04/29 12:54 upstream d72cd4ad4174 77e2b668 .config log report info KCSAN: data-race in ext4_es_lookup_extent / ext4_es_lookup_extent
ci2-upstream-kcsan-gce 2021/04/26 10:03 upstream 9f4ad9e425a1 805b5003 .config log report info KCSAN: data-race in ext4_es_lookup_extent / ext4_es_lookup_extent
ci2-upstream-kcsan-gce 2021/04/20 20:29 upstream 7af08140979a c0ced557 .config log report info KCSAN: data-race in ext4_es_lookup_extent / ext4_es_lookup_extent
ci2-upstream-kcsan-gce 2021/04/10 04:57 upstream 4e04e7513b0f 6a81331a .config log report info KCSAN: data-race in ext4_es_lookup_extent / ext4_es_lookup_extent
* Struck through repros no longer work on HEAD.