KCSAN: data-race in ext4_mark_iloc_dirty / generic_update_time

Status: closed as invalid on 2020/06/18 14:24
Subsystems: ext4
[Documentation on labels]
First crash: 2486d, last: 2263d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in ext4_mark_iloc_dirty / generic_update_time

read to 0xffff8880bb6503c0 of 8 bytes by task 23077 on cpu 0:
 ext4_do_update_inode fs/ext4/inode.c:4985 [inline]
 ext4_mark_iloc_dirty+0x4cd/0x1580 fs/ext4/inode.c:5603
 ext4_mark_inode_dirty+0xe6/0x420 fs/ext4/inode.c:5796
 ext4_dirty_inode+0xad/0xd0 fs/ext4/inode.c:5827
 __mark_inode_dirty+0x5b7/0x940 fs/fs-writeback.c:2258
 generic_update_time+0x184/0x270 fs/inode.c:1682
 update_time+0x7d/0x90 fs/inode.c:1695
 file_update_time+0x205/0x2d0 fs/inode.c:1910
 file_modified fs/inode.c:1933 [inline]
 file_modified+0x60/0x80 fs/inode.c:1918
 ext4_dio_write_checks fs/ext4/file.c:430 [inline]
 ext4_dio_write_iter fs/ext4/file.c:494 [inline]
 ext4_file_write_iter+0xad5/0xd30 fs/ext4/file.c:640
 call_write_iter include/linux/fs.h:1907 [inline]
 do_iter_readv_writev+0x4a7/0x5d0 fs/read_write.c:694
 do_iter_write fs/read_write.c:999 [inline]
 do_iter_write+0x137/0x3a0 fs/read_write.c:980
 vfs_iter_write+0x56/0x80 fs/read_write.c:1040
 iter_file_splice_write+0x530/0x830 fs/splice.c:760
 do_splice_from fs/splice.c:863 [inline]
 direct_splice_actor+0x97/0xb0 fs/splice.c:1037
 splice_direct_to_actor+0x22f/0x540 fs/splice.c:992
 do_splice_direct+0x152/0x1d0 fs/splice.c:1080
 do_sendfile+0x380/0x800 fs/read_write.c:1521
 __do_sys_sendfile64 fs/read_write.c:1582 [inline]
 __se_sys_sendfile64 fs/read_write.c:1568 [inline]
 __x64_sys_sendfile64+0x121/0x140 fs/read_write.c:1568
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff8880bb6503c0 of 16 bytes by task 23089 on cpu 1:
 generic_update_time+0x5c/0x270 fs/inode.c:1669
 update_time+0x7d/0x90 fs/inode.c:1695
 touch_atime+0x13f/0x150 fs/inode.c:1766
 file_accessed include/linux/fs.h:2226 [inline]
 ext4_dio_read_iter fs/ext4/file.c:81 [inline]
 ext4_file_read_iter fs/ext4/file.c:129 [inline]
 ext4_file_read_iter+0x206/0x360 fs/ext4/file.c:114
 call_read_iter include/linux/fs.h:1901 [inline]
 generic_file_splice_read+0x2df/0x470 fs/splice.c:313
 do_splice_to+0xc7/0x100 fs/splice.c:892
 splice_direct_to_actor+0x1b9/0x540 fs/splice.c:971
 do_splice_direct+0x152/0x1d0 fs/splice.c:1080
 do_sendfile+0x380/0x800 fs/read_write.c:1521
 __do_sys_sendfile64 fs/read_write.c:1582 [inline]
 __se_sys_sendfile64 fs/read_write.c:1568 [inline]
 __x64_sys_sendfile64+0x121/0x140 fs/read_write.c:1568
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 23089 Comm: syz-executor.5 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (24):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/06/04 01:45 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 b0d1c0d5 .config console log report ci2-upstream-kcsan-gce
2020/06/03 02:39 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 f3ba1b5b .config console log report ci2-upstream-kcsan-gce
2020/05/28 15:41 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 c7192a2f .config console log report ci2-upstream-kcsan-gce
2020/05/18 11:41 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 24d91142 .config console log report ci2-upstream-kcsan-gce
2020/05/09 16:50 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 88cb3e92 .config console log report ci2-upstream-kcsan-gce
2020/05/09 05:25 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 e97b06d3 .config console log report ci2-upstream-kcsan-gce
2020/05/06 01:11 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 35b8eb30 .config console log report ci2-upstream-kcsan-gce
2020/04/29 22:52 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 2dd552a5 .config console log report ci2-upstream-kcsan-gce
2020/04/15 20:23 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 3f3c5574 .config console log report ci2-upstream-kcsan-gce
2020/04/14 00:41 https://github.com/google/ktsan.git kcsan 40959e34d670 7c54686a .config console log report ci2-upstream-kcsan-gce
2020/04/04 07:04 https://github.com/google/ktsan.git kcsan 40959e34d670 ef26b610 .config console log report ci2-upstream-kcsan-gce
2020/03/25 18:10 https://github.com/google/ktsan.git kcsan 40959e34d670 e8e6c7d2 .config console log report ci2-upstream-kcsan-gce
2020/03/25 06:37 https://github.com/google/ktsan.git kcsan 40959e34d670 41f049cc .config console log report ci2-upstream-kcsan-gce
2020/03/09 14:55 https://github.com/google/ktsan.git kcsan 941e0d917bbf 35f53e45 .config console log report ci2-upstream-kcsan-gce
2020/03/06 14:09 https://github.com/google/ktsan.git kcsan 766d004d1b85 7fb694ef .config console log report ci2-upstream-kcsan-gce
2020/02/11 03:04 https://github.com/google/ktsan.git kcsan f60f0f543333 d9e55b05 .config console log report ci2-upstream-kcsan-gce
2020/02/10 07:27 https://github.com/google/ktsan.git kcsan f60f0f543333 35f5e45e .config console log report ci2-upstream-kcsan-gce
2020/02/07 03:48 https://github.com/google/ktsan.git kcsan 245a43005292 06150bf1 .config console log report ci2-upstream-kcsan-gce
2020/01/24 08:22 https://github.com/google/ktsan.git kcsan 245a43005292 2e95ab33 .config console log report ci2-upstream-kcsan-gce
2019/12/17 15:18 https://github.com/google/ktsan.git kcsan 245a43005292 1af3875f .config console log report ci2-upstream-kcsan-gce
2019/11/28 23:19 https://github.com/google/ktsan.git kcsan ef798c30ba4e 76357d6f .config console log report ci2-upstream-kcsan-gce
2019/11/19 09:52 https://github.com/google/ktsan.git kcsan 5863cc791e4c 432c7650 .config console log report ci2-upstream-kcsan-gce
2019/11/19 09:47 https://github.com/google/ktsan.git kcsan 5863cc791e4c 432c7650 .config console log report ci2-upstream-kcsan-gce
2019/10/24 09:28 https://github.com/google/ktsan.git kcsan 05f2236801fe d01bb02a .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.