syzbot


BUG: KCSAN: data-race in ext4_es_lookup_extent and ext4_es_lookup_extent

Status: closed as invalid on 2019/10/04 18:08
Subsystems: ext4
[Documentation on labels]
First crash: 1666d, last: 1666d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in ext4_es_lookup_extent+0x3ba/0x510 fs/ext4/extents_status.c:950 and ext4_es_lookup_extent+0x3d3/0x510

write to 0xffff888126a68428 of 8 bytes by task 7329 on cpu 1:
 ext4_es_lookup_extent+0x3d3/0x510 fs/ext4/extents_status.c:950
 ext4_map_blocks+0xc2/0xf70 fs/ext4/inode.c:530
 ext4_getblk+0x30b/0x380 fs/ext4/inode.c:974
 ext4_bread+0x4a/0x190 fs/ext4/inode.c:1024
 __ext4_read_dirblock+0x3e/0x700 fs/ext4/namei.c:112
 htree_dirblock_to_tree+0x8c/0x560 fs/ext4/namei.c:997
 ext4_htree_fill_tree+0x179/0x6b0 fs/ext4/namei.c:1116
 ext4_dx_readdir fs/ext4/dir.c:576 [inline]
 ext4_readdir+0x54d/0x1e30 fs/ext4/dir.c:124
 iterate_dir+0x312/0x380 fs/readdir.c:51
 __do_sys_getdents fs/readdir.c:231 [inline]
 __se_sys_getdents fs/readdir.c:212 [inline]
 __x64_sys_getdents+0x14b/0x280 fs/readdir.c:212
 do_syscall_64+0xcf/0x2f0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888126a68428 of 8 bytes by task 7299 on cpu 0:
 ext4_es_lookup_extent+0x3ba/0x510 fs/ext4/extents_status.c:950
 ext4_map_blocks+0xc2/0xf70 fs/ext4/inode.c:530
 ext4_mpage_readpages+0x92b/0x1270 fs/ext4/readpage.c:182
 ext4_readpages+0x92/0xc0 fs/ext4/inode.c:3388
 read_pages+0xa2/0x2d0 mm/readahead.c:126
 __do_page_cache_readahead+0x353/0x390 mm/readahead.c:212
 ra_submit mm/internal.h:62 [inline]
 ondemand_readahead+0x35d/0x710 mm/readahead.c:492
 page_cache_async_readahead+0x22c/0x250 mm/readahead.c:574
 generic_file_buffered_read mm/filemap.c:2079 [inline]
 generic_file_read_iter+0xffc/0x1440 mm/filemap.c:2344
 ext4_file_read_iter fs/ext4/file.c:77 [inline]
 ext4_file_read_iter+0xfa/0x240 fs/ext4/file.c:65
 call_read_iter include/linux/fs.h:1864 [inline]
 new_sync_read+0x389/0x4f0 fs/read_write.c:414
 __vfs_read+0xb1/0xc0 fs/read_write.c:427
 integrity_kernel_read+0xa1/0xe0 security/integrity/iint.c:200

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7299 Comm: syz-fuzzer Not tainted 5.3.0+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/10/04 12:20 https://github.com/google/ktsan.git kcsan 6769d3ca0f23 b2f369e5 .config console log report ci2-upstream-kcsan-gce
2019/10/04 12:13 https://github.com/google/ktsan.git kcsan 6769d3ca0f23 b2f369e5 .config console log report ci2-upstream-kcsan-gce
2019/10/04 12:08 https://github.com/google/ktsan.git kcsan 6769d3ca0f23 b2f369e5 .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.