syzbot


KCSAN: data-race in ext4_fill_raw_inode / ext4_writepages

Status: auto-closed as invalid on 2021/12/20 11:22
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 378d, last: 378d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in ext4_fill_raw_inode / ext4_writepages

write to 0xffff88812c0b31e8 of 8 bytes by task 23317 on cpu 0:
 mpage_map_and_submit_extent fs/ext4/inode.c:2502 [inline]
 ext4_writepages+0x147a/0x1e80 fs/ext4/inode.c:2795
 do_writepages+0x1cb/0x330 mm/page-writeback.c:2364
 __writeback_single_inode+0x80/0x4d0 fs/fs-writeback.c:1616
 writeback_sb_inodes+0x677/0xdf0 fs/fs-writeback.c:1881
 wb_writeback+0x26b/0x650 fs/fs-writeback.c:2054
 wb_do_writeback+0x101/0x560 fs/fs-writeback.c:2197
 wb_workfn+0xc8/0x440 fs/fs-writeback.c:2238
 process_one_work+0x3fc/0x980 kernel/workqueue.c:2298
 worker_thread+0x616/0xa70 kernel/workqueue.c:2445
 kthread+0x2c7/0x2e0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30

read to 0xffff88812c0b31e8 of 8 bytes by task 24699 on cpu 1:
 ext4_fill_raw_inode+0x752/0xea0 fs/ext4/inode.c:4337
 ext4_do_update_inode fs/ext4/inode.c:5094 [inline]
 ext4_mark_iloc_dirty+0x364/0x890 fs/ext4/inode.c:5694
 __ext4_mark_inode_dirty+0x4ec/0x5f0 fs/ext4/inode.c:5890
 ext4_dirty_inode+0x86/0xa0 fs/ext4/inode.c:5919
 __mark_inode_dirty+0x72/0x6c0 fs/fs-writeback.c:2399
 mark_inode_dirty include/linux/fs.h:2451 [inline]
 generic_write_end+0x157/0x180 fs/buffer.c:2202
 ext4_da_write_end+0x4de/0x630 fs/ext4/inode.c:3059
 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

value changed: 0x0000000000000000 -> 0x00000000000f0000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 24699 Comm: syz-executor.4 Tainted: G        W         5.16.0-rc1-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 2021/11/15 11:22 upstream 8ab774587903 75b04091 .config log report info KCSAN: data-race in ext4_fill_raw_inode / ext4_writepages
* Struck through repros no longer work on HEAD.