syzbot


KCSAN: data-race in __ext4_journal_start_sb / jbd2_journal_update_sb_log_tail (2)

Status: auto-closed as invalid on 2022/01/04 23:22
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 390d, last: 362d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in __ext4_journal_start_sb / jbd2_journal_update_sb_log_tail 3 654d 658d 0/24 auto-closed as invalid on 2021/03/18 16:29

Sample crash report:
==================================================================
BUG: KCSAN: data-race in __ext4_journal_start_sb / jbd2_journal_update_sb_log_tail

write to 0xffff888103665000 of 8 bytes by task 1403 on cpu 1:
 jbd2_journal_update_sb_log_tail+0x176/0x1b0 fs/jbd2/journal.c:1689
 jbd2_journal_commit_transaction+0x21e/0x3460 fs/jbd2/commit.c:430
 kjournald2+0x263/0x480 fs/jbd2/journal.c:213
 kthread+0x2c7/0x2e0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30

read to 0xffff888103665000 of 8 bytes by task 29439 on cpu 0:
 is_journal_aborted include/linux/jbd2.h:1695 [inline]
 ext4_journal_check_start fs/ext4/ext4_jbd2.c:82 [inline]
 __ext4_journal_start_sb+0xf2/0x310 fs/ext4/ext4_jbd2.c:98
 __ext4_journal_start fs/ext4/ext4_jbd2.h:326 [inline]
 ext4_dirty_inode+0x58/0xa0 fs/ext4/inode.c:5916
 __mark_inode_dirty+0x72/0x6c0 fs/fs-writeback.c:2399
 generic_update_time fs/inode.c:1782 [inline]
 inode_update_time+0x1b4/0x1d0 fs/inode.c:1795
 file_update_time+0x1f3/0x230 fs/inode.c:2012
 ext4_page_mkwrite+0x14d/0xf40 fs/ext4/inode.c:6037
 do_page_mkwrite mm/memory.c:2856 [inline]
 do_shared_fault mm/memory.c:4229 [inline]
 do_fault mm/memory.c:4297 [inline]
 handle_pte_fault mm/memory.c:4551 [inline]
 __handle_mm_fault mm/memory.c:4686 [inline]
 handle_mm_fault+0xdb8/0x1590 mm/memory.c:4784
 do_user_addr_fault+0x609/0xbe0 arch/x86/mm/fault.c:1397
 handle_page_fault arch/x86/mm/fault.c:1485 [inline]
 exc_page_fault+0x91/0x290 arch/x86/mm/fault.c:1541
 asm_exc_page_fault+0x1e/0x30

value changed: 0x0000000000000038 -> 0x0000000000000230

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 29439 Comm: syz-executor.5 Not tainted 5.16.0-rc3-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 2021/11/30 23:18 upstream f080815fdb3e 80270552 .config log report info KCSAN: data-race in __ext4_journal_start_sb / jbd2_journal_update_sb_log_tail
ci2-upstream-kcsan-gce 2021/11/13 23:20 upstream a9b9669d9822 75b04091 .config log report info KCSAN: data-race in __ext4_journal_start_sb / jbd2_journal_update_sb_log_tail
ci2-upstream-kcsan-gce 2021/11/03 13:54 upstream dcd68326d29b 4c1be0be .config log report info KCSAN: data-race in __ext4_journal_start_sb / jbd2_journal_update_sb_log_tail
* Struck through repros no longer work on HEAD.