syzbot


KCSAN: data-race in ext4_es_lookup_extent / ext4_es_lookup_extent (7)

Status: auto-closed as invalid on 2021/02/19 02:54
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 715d, last: 694d
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 953d 953d 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 805d 862d 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 756d 732d 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 1045d 1132d 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 560d 609d 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 393d 403d 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 1151d 1151d 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 1151d 1162d 0/24 closed as invalid on 2019/10/15 15:50

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

write to 0xffff88801003f9f8 of 8 bytes by task 10576 on cpu 0:
 ext4_es_set_referenced fs/ext4/extents_status.h:194 [inline]
 ext4_es_lookup_extent+0x2f7/0x500 fs/ext4/extents_status.c:968
 ext4_map_blocks+0x105/0xfc0 fs/ext4/inode.c:529
 ext4_mpage_readpages+0x630/0x14c0 fs/ext4/readpage.c:304
 ext4_readahead+0x99/0xa0 fs/ext4/inode.c:3261
 read_pages+0xa0/0x6e0 mm/readahead.c:130
 page_cache_ra_unbounded+0x464/0x4c0 mm/readahead.c:238
 ondemand_readahead+0x560/0x780 mm/readahead.c:267
 page_cache_sync_ra+0x1ab/0x1c0 mm/readahead.c:577
 page_cache_sync_readahead include/linux/pagemap.h:839 [inline]
 generic_file_buffered_read_get_pages+0x234/0xaf0 mm/filemap.c:2361
 generic_file_buffered_read+0x27f/0x9a0 mm/filemap.c:2481
 generic_file_read_iter+0x80/0x3d0 mm/filemap.c:2633
 ext4_file_read_iter+0x2d0/0x420 fs/ext4/file.c:74
 call_read_iter include/linux/fs.h:1895 [inline]
 generic_file_splice_read+0x22a/0x310 fs/splice.c:311
 do_splice_to fs/splice.c:788 [inline]
 splice_direct_to_actor+0x2aa/0x650 fs/splice.c:867
 do_splice_direct+0xf5/0x170 fs/splice.c:976
 do_sendfile+0x5db/0xca0 fs/read_write.c:1257
 __do_sys_sendfile64 fs/read_write.c:1318 [inline]
 __se_sys_sendfile64 fs/read_write.c:1304 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1304
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88801003f9f8 of 8 bytes by task 10588 on cpu 1:
 ext4_es_lookup_extent+0x2a8/0x500 fs/ext4/extents_status.c:966
 ext4_map_blocks+0x105/0xfc0 fs/ext4/inode.c:529
 ext4_iomap_begin+0x1b3/0x6a0 fs/ext4/inode.c:3473
 iomap_apply+0x8d/0x4a0 fs/iomap/apply.c:46
 __iomap_dio_rw+0x448/0x9b0 fs/iomap/direct-io.c:517
 iomap_dio_rw+0x30/0x70 fs/iomap/direct-io.c:605
 ext4_dio_write_iter fs/ext4/file.c:552 [inline]
 ext4_file_write_iter+0xe06/0x1090 fs/ext4/file.c:662
 call_write_iter include/linux/fs.h:1901 [inline]
 new_sync_write fs/read_write.c:518 [inline]
 vfs_write+0x6d4/0x7c0 fs/read_write.c:605
 ksys_write+0xce/0x180 fs/read_write.c:658
 __do_sys_write fs/read_write.c:670 [inline]
 __se_sys_write fs/read_write.c:667 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:667
 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: 1 PID: 10588 Comm: syz-executor.5 Not tainted 5.11.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2021/01/15 02:43 upstream 146620506274 468dbb55 .config log report info
ci2-upstream-kcsan-gce 2020/12/25 00:53 upstream 3913d00ac51a c2c1d1dd .config log report info
* Struck through repros no longer work on HEAD.