syzbot


KCSAN: data-race in xas_create / xas_find (5)

Status: auto-closed as invalid on 2022/07/21 09:43
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 169d, last: 169d
similar bugs (4):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in xas_create / xas_find (4) 3 211d 249d 0/24 auto-closed as invalid on 2022/06/09 16:26
upstream KCSAN: data-race in xas_create / xas_find (2) 5 471d 543d 0/24 auto-closed as invalid on 2021/09/22 15:56
upstream KCSAN: data-race in xas_create / xas_find (3) 11 320d 436d 0/24 auto-closed as invalid on 2022/02/20 21:56
upstream KCSAN: data-race in xas_create / xas_find 2 582d 596d 0/24 auto-closed as invalid on 2021/06/03 16:29

Sample crash report:
loop0: detected capacity change from 0 to 264192
==================================================================
BUG: KCSAN: data-race in xas_create / xas_find

write to 0xffff888147701901 of 1 bytes by task 10490 on cpu 1:
 xas_expand lib/xarray.c:614 [inline]
 xas_create+0x68a/0xb20 lib/xarray.c:655
 xas_store+0x71/0xc90 lib/xarray.c:789
 __filemap_add_folio+0x271/0x7f0 mm/filemap.c:900
 filemap_add_folio+0x6b/0x150 mm/filemap.c:959
 page_cache_ra_unbounded+0x19e/0x2e0 mm/readahead.c:245
 do_page_cache_ra mm/readahead.c:293 [inline]
 force_page_cache_ra+0x1c6/0x200 mm/readahead.c:324
 page_cache_sync_ra+0xc8/0xf0 mm/readahead.c:693
 page_cache_sync_readahead include/linux/pagemap.h:1234 [inline]
 filemap_get_pages mm/filemap.c:2592 [inline]
 filemap_read+0x3e5/0x1400 mm/filemap.c:2679
 blkdev_read_iter+0x2c6/0x370 block/fops.c:594
 call_read_iter include/linux/fs.h:2052 [inline]
 new_sync_read fs/read_write.c:401 [inline]
 vfs_read+0x5a5/0x6a0 fs/read_write.c:482
 ksys_read+0xe8/0x1a0 fs/read_write.c:620
 __do_sys_read fs/read_write.c:630 [inline]
 __se_sys_read fs/read_write.c:628 [inline]
 __x64_sys_read+0x3e/0x50 fs/read_write.c:628
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

read to 0xffff888147701901 of 1 bytes by task 17812 on cpu 0:
 xas_find+0x35d/0x3d0 lib/xarray.c:1264
 find_get_entry mm/filemap.c:2030 [inline]
 find_get_entries+0x90/0x2e0 mm/filemap.c:2085
 truncate_inode_pages_range+0x76d/0xae0 mm/truncate.c:404
 truncate_inode_pages+0x20/0x30 mm/truncate.c:452
 kill_bdev block/bdev.c:77 [inline]
 set_blocksize+0x24e/0x270 block/bdev.c:153
 sb_set_blocksize block/bdev.c:162 [inline]
 sb_min_blocksize+0x92/0x110 block/bdev.c:178
 __ext4_fill_super fs/ext4/super.c:4326 [inline]
 ext4_fill_super+0x371/0x4f10 fs/ext4/super.c:5499
 get_tree_bdev+0x2b4/0x3b0 fs/super.c:1292
 ext4_get_tree+0x18/0x20 fs/ext4/super.c:5529
 vfs_get_tree+0x49/0x190 fs/super.c:1497
 do_new_mount+0x200/0x650 fs/namespace.c:3040
 path_mount+0x4b1/0xb60 fs/namespace.c:3370
 do_mount fs/namespace.c:3383 [inline]
 __do_sys_mount fs/namespace.c:3591 [inline]
 __se_sys_mount+0x281/0x2d0 fs/namespace.c:3568
 __x64_sys_mount+0x63/0x70 fs/namespace.c:3568
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

value changed: 0x03 -> 0x00

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 17812 Comm: syz-executor.0 Not tainted 5.19.0-rc2-syzkaller-00060-g30306f6194ca-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
EXT4-fs (loop0): Invalid log block size: 1437270015

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2022/06/16 09:35 upstream 30306f6194ca 1719ee24 .config log report info KCSAN: data-race in xas_create / xas_find
* Struck through repros no longer work on HEAD.