syzbot


KCSAN: data-race in ext4_write_end / ext4_writepage

Status: auto-closed as invalid on 2021/12/27 03:28
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 399d, last: 378d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in ext4_write_end / ext4_writepage

write to 0xffff888105b4a718 of 8 bytes by task 6206 on cpu 1:
 i_size_write include/linux/fs.h:913 [inline]
 ext4_update_inode_size fs/ext4/ext4.h:3422 [inline]
 ext4_write_end+0x16d/0x710 fs/ext4/inode.c:1303
 generic_perform_write+0x261/0x400 mm/filemap.c:3767
 ext4_buffered_write_iter+0x25b/0x380 fs/ext4/file.c:269
 ext4_file_write_iter+0x2e7/0x1200
 call_write_iter include/linux/fs.h:2162 [inline]
 new_sync_write fs/read_write.c:503 [inline]
 vfs_write+0x7f5/0x950 fs/read_write.c:590
 ksys_write+0xd9/0x190 fs/read_write.c:643
 __do_sys_write fs/read_write.c:655 [inline]
 __se_sys_write fs/read_write.c:652 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:652
 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 0xffff888105b4a718 of 8 bytes by task 1402 on cpu 0:
 i_size_read include/linux/fs.h:891 [inline]
 ext4_writepage+0xbe/0xea0 fs/ext4/inode.c:2004
 __writepage+0x38/0xd0 mm/page-writeback.c:2320
 write_cache_pages+0x454/0x7f0 mm/page-writeback.c:2255
 generic_writepages+0x7c/0xc0 mm/page-writeback.c:2346
 jbd2_journal_submit_inode_data_buffers+0xb2/0xe0 fs/jbd2/commit.c:206
 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: 0x0000000000dfd000 -> 0x0000000000dfe000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 1402 Comm: jbd2/sda1-8 Not tainted 5.16.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (4):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2021/11/22 03:24 upstream 40c93d7fff6f 4eb20a4e .config log report info KCSAN: data-race in ext4_write_end / ext4_writepage
ci2-upstream-kcsan-gce 2021/11/17 02:52 upstream 8ab774587903 cafff8b6 .config log report info KCSAN: data-race in ext4_write_end / ext4_writepage
ci2-upstream-kcsan-gce 2021/11/13 15:25 upstream 66f4beaa6c1d 75b04091 .config log report info KCSAN: data-race in ext4_write_end / ext4_writepage
ci2-upstream-kcsan-gce 2021/11/01 05:36 upstream 8bb7eca972ad 098b5d53 .config log report info KCSAN: data-race in ext4_write_end / ext4_writepage
* Struck through repros no longer work on HEAD.