syzbot


KCSAN: data-race in ext4_es_lookup_extent / ext4_es_lookup_extent (5)

Status: auto-closed as invalid on 2020/10/30 13:53
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 791d, last: 735d
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 882d 882d 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 (6) 1 685d 662d 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 974d 1061d 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 (8) 6 489d 538d 0/24 auto-closed as invalid on 2021/07/03 03:54
upstream KCSAN: data-race in ext4_es_lookup_extent / ext4_es_lookup_extent (9) 4 322d 332d 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 1080d 1080d 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 1081d 1092d 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 623d 644d 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 0xffff888092c7a570 of 8 bytes by task 12820 on cpu 1:
 ext4_es_set_referenced fs/ext4/extents_status.h:194 [inline]
 ext4_es_lookup_extent+0x296/0x4f0 fs/ext4/extents_status.c:950
 ext4_map_blocks+0xad/0xf40 fs/ext4/inode.c:517
 ext4_mpage_readpages+0x703/0x13a0 fs/ext4/readpage.c:304
 ext4_readahead+0x93/0xa0 fs/ext4/inode.c:3241
 read_pages+0x9c/0x700 mm/readahead.c:130
 page_cache_readahead_unbounded+0x41a/0x470 mm/readahead.c:244
 ondemand_readahead+0x4e4/0x6e0 mm/readahead.c:273
 page_cache_sync_readahead+0x178/0x1a0 mm/readahead.c:585
 generic_file_buffered_read+0x2ec/0x1f60 mm/filemap.c:2199
 generic_file_read_iter+0x7d/0x3e0 mm/filemap.c:2503
 ext4_file_read_iter+0x2d8/0x420 fs/ext4/file.c:74
 call_read_iter include/linux/fs.h:1876 [inline]
 generic_file_splice_read+0x22b/0x310 fs/splice.c:312
 do_splice_to fs/splice.c:870 [inline]
 splice_direct_to_actor+0x2a8/0x660 fs/splice.c:950
 do_splice_direct+0xf2/0x170 fs/splice.c:1059
 do_sendfile+0x56a/0xba0 fs/read_write.c:1540
 __do_sys_sendfile64 fs/read_write.c:1601 [inline]
 __se_sys_sendfile64 fs/read_write.c:1587 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1587
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888092c7a570 of 8 bytes by task 12823 on cpu 0:
 ext4_es_lookup_extent+0x24c/0x4f0 fs/ext4/extents_status.c:948
 ext4_map_blocks+0xad/0xf40 fs/ext4/inode.c:517
 ext4_iomap_alloc fs/ext4/inode.c:3401 [inline]
 ext4_iomap_begin+0x46e/0x5f0 fs/ext4/inode.c:3440
 iomap_apply+0x8b/0x540 fs/iomap/apply.c:46
 iomap_dio_rw+0x434/0x980 fs/iomap/direct-io.c:506
 ext4_dio_write_iter fs/ext4/file.c:548 [inline]
 ext4_file_write_iter+0xdd5/0x1060 fs/ext4/file.c:658
 call_write_iter include/linux/fs.h:1882 [inline]
 do_iter_readv_writev+0x32e/0x3d0 fs/read_write.c:713
 do_iter_write+0x112/0x4b0 fs/read_write.c:1018
 vfs_iter_write+0x4c/0x70 fs/read_write.c:1059
 iter_file_splice_write+0x41a/0x770 fs/splice.c:750
 do_splice_from fs/splice.c:846 [inline]
 direct_splice_actor+0x95/0x160 fs/splice.c:1016
 splice_direct_to_actor+0x365/0x660 fs/splice.c:971
 do_splice_direct+0xf2/0x170 fs/splice.c:1059
 do_sendfile+0x56a/0xba0 fs/read_write.c:1540
 __do_sys_sendfile64 fs/read_write.c:1601 [inline]
 __se_sys_sendfile64 fs/read_write.c:1587 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1587
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 12823 Comm: syz-executor.1 Not tainted 5.9.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (3):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2020/09/25 13:49 upstream 171d4ff79f96 4a006f63 .config log report info
ci2-upstream-kcsan-gce 2020/08/23 06:42 upstream c3d8f220d012 1da71ab0 .config log report
ci2-upstream-kcsan-gce 2020/07/30 19:08 upstream 83bdc7275e62 b0947553 .config log report
* Struck through repros no longer work on HEAD.