syzbot


KCSAN: data-race in __filemap_add_folio / jbd2_journal_submit_inode_data_buffers

Status: auto-closed as invalid on 2021/12/15 14:34
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 392d, last: 392d
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __filemap_add_folio / jbd2_journal_submit_inode_data_buffers (3) 2 212d 212d 0/24 closed as invalid on 2022/05/13 11:20
upstream KCSAN: data-race in __filemap_add_folio / jbd2_journal_submit_inode_data_buffers (2) 1 353d 353d 0/24 auto-closed as invalid on 2022/01/23 07:11

Sample crash report:
==================================================================
BUG: KCSAN: data-race in __filemap_add_folio / jbd2_journal_submit_inode_data_buffers

write to 0xffff88813a4c7ca0 of 8 bytes by task 3331 on cpu 0:
 __filemap_add_folio+0x256/0x4d0 mm/filemap.c:946
 filemap_add_folio+0x6b/0x150 mm/filemap.c:999
 __filemap_get_folio+0x4c4/0x690 mm/filemap.c:1962
 pagecache_get_page+0x26/0xe0 mm/folio-compat.c:125
 grab_cache_page_write_begin+0x3f/0x50 mm/folio-compat.c:139
 mext_page_double_lock fs/ext4/move_extent.c:142 [inline]
 move_extent_per_page fs/ext4/move_extent.c:303 [inline]
 ext4_move_extents+0xe96/0x2210 fs/ext4/move_extent.c:673
 __ext4_ioctl fs/ext4/ioctl.c:988 [inline]
 ext4_ioctl+0x1532/0x2170 fs/ext4/ioctl.c:1279
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:860
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88813a4c7ca0 of 8 bytes by task 1403 on cpu 1:
 jbd2_journal_submit_inode_data_buffers+0x5b/0xe0 fs/jbd2/commit.c:195
 ext4_journal_submit_inode_data_buffers+0x55/0x110 fs/ext4/super.c:531
 journal_submit_data_buffers+0xf0/0x260 fs/jbd2/commit.c:256
 jbd2_journal_commit_transaction+0x86f/0x3460 fs/jbd2/commit.c:591
 kjournald2+0x263/0x480 fs/jbd2/journal.c:213
 kthread+0x2c7/0x2e0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30

value changed: 0x00000000000000bd -> 0x00000000000000be

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 1403 Comm: jbd2/sda1-8 Not tainted 5.15.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2021/11/10 14:26 upstream cb690f5238d7 75b04091 .config log report info KCSAN: data-race in __filemap_add_folio / jbd2_journal_submit_inode_data_buffers
* Struck through repros no longer work on HEAD.