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KCSAN: data-race in generic_write_end / mpage_submit_page (2)

Status: auto-closed as invalid on 2020/08/02 18:32
Subsystems: ext4
[Documentation on labels]
Reported-by: syzbot+29a42d94d01cf2721f04@syzkaller.appspotmail.com
First crash: 1651d, last: 1395d
▶ ▼ Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in generic_write_end / mpage_submit_page ext4 3 1654d 1663d 0/26 closed as invalid on 2019/10/15 15:50

Sample crash report:
==================================================================
BUG: KCSAN: data-race in generic_write_end / mpage_submit_page

write to 0xffff88811eb06678 of 8 bytes by task 17614 on cpu 0:
 i_size_write include/linux/fs.h:896 [inline]
 generic_write_end+0xac/0x2a0 fs/buffer.c:2187
 ext4_da_write_end+0x55e/0x6d0 fs/ext4/inode.c:3092
 generic_perform_write+0x233/0x380 mm/filemap.c:3310
 ext4_buffered_write_iter+0x2b1/0x390 fs/ext4/file.c:270
 ext4_file_write_iter+0x4a3/0xfd0 fs/ext4/file.c:498
 call_write_iter include/linux/fs.h:1907 [inline]
 new_sync_write fs/read_write.c:484 [inline]
 __vfs_write+0x2d8/0x340 fs/read_write.c:497
 vfs_write+0x19b/0x350 fs/read_write.c:559
 ksys_write+0xce/0x180 fs/read_write.c:612
 __do_sys_write fs/read_write.c:624 [inline]
 __se_sys_write fs/read_write.c:621 [inline]
 __x64_sys_write+0x3e/0x50 fs/read_write.c:621
 do_syscall_64+0x71/0x120 arch/x86/entry/common.c:359
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88811eb06678 of 8 bytes by task 7 on cpu 1:
 i_size_read include/linux/fs.h:874 [inline]
 mpage_submit_page+0x67/0x170 fs/ext4/inode.c:2076
 mpage_map_and_submit_buffers fs/ext4/inode.c:2330 [inline]
 mpage_map_and_submit_extent fs/ext4/inode.c:2469 [inline]
 ext4_writepages+0x106b/0x1cb0 fs/ext4/inode.c:2782
 do_writepages+0x7b/0x150 mm/page-writeback.c:2354
 __writeback_single_inode+0x81/0x610 fs/fs-writeback.c:1452
 writeback_sb_inodes+0x5b8/0xe00 fs/fs-writeback.c:1716
 wb_writeback+0x2b8/0x730 fs/fs-writeback.c:1892
 wb_do_writeback+0x108/0x600 fs/fs-writeback.c:2037
 wb_workfn+0xb8/0x430 fs/fs-writeback.c:2078
 process_one_work+0x3cb/0x990 kernel/workqueue.c:2269
 worker_thread+0x665/0xbe0 kernel/workqueue.c:2415
 kthread+0x210/0x220 kernel/kthread.c:291
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 7 Comm: kworker/u4:0 Not tainted 5.8.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: writeback wb_workfn (flush-8:0)
==================================================================

Crashes (166):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/06/28 18:31 upstream 719fdd32921f a2cdad9d .config console log report ci2-upstream-kcsan-gce
2020/06/28 11:21 upstream 719fdd32921f a2cdad9d .config console log report ci2-upstream-kcsan-gce
2020/06/27 20:01 upstream 6116dea80dfd a2cdad9d .config console log report ci2-upstream-kcsan-gce
2020/06/27 14:32 upstream 1590a2e1c681 2defc703 .config console log report ci2-upstream-kcsan-gce
2020/06/27 12:47 upstream 1590a2e1c681 032b4239 .config console log report ci2-upstream-kcsan-gce
2020/06/27 09:05 upstream 1590a2e1c681 032b4239 .config console log report ci2-upstream-kcsan-gce
2020/06/27 02:39 upstream 1590a2e1c681 ffec44b5 .config console log report ci2-upstream-kcsan-gce
2020/06/26 11:28 upstream 4a21185cda0f b202c7a8 .config console log report ci2-upstream-kcsan-gce
2020/06/26 02:48 upstream 4a21185cda0f aea82c00 .config console log report ci2-upstream-kcsan-gce
2020/06/26 01:07 upstream 908f7d12d3ba aea82c00 .config console log report ci2-upstream-kcsan-gce
2020/06/25 22:44 upstream 908f7d12d3ba aea82c00 .config console log report ci2-upstream-kcsan-gce
2020/06/25 12:25 upstream 8be3a53e18e0 c7b4497a .config console log report ci2-upstream-kcsan-gce
2020/06/25 10:59 upstream 8be3a53e18e0 c7b4497a .config console log report ci2-upstream-kcsan-gce
2020/06/25 09:47 upstream 8be3a53e18e0 9d60b18e .config console log report ci2-upstream-kcsan-gce
2020/06/24 18:40 upstream 26e122e97a3d 41694dbf .config console log report ci2-upstream-kcsan-gce
2020/06/24 17:19 upstream 3e08a95294a4 41694dbf .config console log report ci2-upstream-kcsan-gce
2020/06/24 11:50 upstream 3e08a95294a4 41694dbf .config console log report ci2-upstream-kcsan-gce
2020/06/24 10:34 upstream 3e08a95294a4 41694dbf .config console log report ci2-upstream-kcsan-gce
2020/06/23 18:53 upstream 3e08a95294a4 6930bbef .config console log report ci2-upstream-kcsan-gce
2020/06/23 14:36 upstream dd0d718152e4 54566aff .config console log report ci2-upstream-kcsan-gce
2020/06/21 15:34 upstream 64677779e896 4f2acff9 .config console log report ci2-upstream-kcsan-gce
2020/06/20 10:24 upstream 672f9255a727 c655ec77 .config console log report ci2-upstream-kcsan-gce
2020/06/19 13:42 upstream 5e857ce6eae7 123cf502 .config console log report ci2-upstream-kcsan-gce
2020/06/18 14:08 upstream 1b5044021070 3ea11d3f .config console log report ci2-upstream-kcsan-gce
2020/06/17 23:24 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 d45a4d69 .config console log report ci2-upstream-kcsan-gce
2020/06/16 23:07 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 b9f3810b .config console log report ci2-upstream-kcsan-gce
2020/06/13 11:15 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 dbce178a .config console log report ci2-upstream-kcsan-gce
2020/06/12 16:23 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 3036d6fd .config console log report ci2-upstream-kcsan-gce
2020/06/11 00:35 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 3ab7a05a .config console log report ci2-upstream-kcsan-gce
2020/06/10 12:27 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 5caaad3a .config console log report ci2-upstream-kcsan-gce
2020/06/10 00:36 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 860c4de9 .config console log report ci2-upstream-kcsan-gce
2020/06/08 23:24 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 0d60b78a .config console log report ci2-upstream-kcsan-gce
2020/06/07 21:19 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 7751efd0 .config console log report ci2-upstream-kcsan-gce
2020/06/05 13:24 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 d36418e9 .config console log report ci2-upstream-kcsan-gce
2020/06/05 01:41 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 2420d1bc .config console log report ci2-upstream-kcsan-gce
2020/06/03 12:42 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 a5ce5de0 .config console log report ci2-upstream-kcsan-gce
2020/06/02 12:27 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 52fd7b7d .config console log report ci2-upstream-kcsan-gce
2020/05/26 00:45 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 8ca3b7d2 .config console log report ci2-upstream-kcsan-gce
2020/05/25 12:36 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 73964a9b .config console log report ci2-upstream-kcsan-gce
2020/05/25 00:45 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 11284182 .config console log report ci2-upstream-kcsan-gce
2020/05/24 12:38 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 ce7ca010 .config console log report ci2-upstream-kcsan-gce
2020/05/23 22:29 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 96c92ad3 .config console log report ci2-upstream-kcsan-gce
2020/05/20 14:08 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 4afdfa20 .config console log report ci2-upstream-kcsan-gce
2020/05/18 10:11 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 24d91142 .config console log report ci2-upstream-kcsan-gce
2020/05/16 00:24 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 37bccd4e .config console log report ci2-upstream-kcsan-gce
2019/10/17 01:44 https://github.com/google/ktsan.git kcsan a6311db074d9 8c88c9c1 .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.