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KCSAN: data-race in ext4_set_iomap / inode_sync_complete

Status: closed as invalid on 2020/06/18 14:24
Subsystems: ext4
[Documentation on labels]
First crash: 2052d, last: 1889d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in ext4_set_iomap / inode_sync_complete

write to 0xffff88811d103880 of 8 bytes by task 19424 on cpu 1:
 inode_sync_complete+0x34/0x70 fs/fs-writeback.c:1197
 writeback_single_inode+0x27a/0x2f0 fs/fs-writeback.c:1578
 sync_inode fs/fs-writeback.c:2602 [inline]
 sync_inode_metadata+0x75/0xa0 fs/fs-writeback.c:2622
 ext4_fsync_nojournal fs/ext4/fsync.c:94 [inline]
 ext4_sync_file+0x47a/0x8b0 fs/ext4/fsync.c:172
 vfs_fsync_range+0x7c/0x150 fs/sync.c:197
 generic_write_sync include/linux/fs.h:2872 [inline]
 iomap_dio_complete+0x37a/0x3c0 fs/iomap/direct-io.c:120
 iomap_dio_rw+0x8e3/0x9a0 fs/iomap/direct-io.c:569
 ext4_dio_write_iter fs/ext4/file.c:532 [inline]
 ext4_file_write_iter+0xb84/0xd30 fs/ext4/file.c:640
 call_write_iter include/linux/fs.h:1907 [inline]
 new_sync_write+0x303/0x400 fs/read_write.c:484
 __vfs_write+0x9e/0xb0 fs/read_write.c:497
 vfs_write fs/read_write.c:559 [inline]
 vfs_write+0x189/0x380 fs/read_write.c:543
 ksys_write+0xc5/0x1a0 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+0x49/0x60 fs/read_write.c:621
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88811d103880 of 8 bytes by task 19427 on cpu 0:
 ext4_inode_datasync_dirty fs/ext4/inode.c:3307 [inline]
 ext4_set_iomap+0x396/0x470 fs/ext4/inode.c:3322
 ext4_iomap_begin_report+0x3de/0x410 fs/ext4/inode.c:3569
 iomap_apply+0xd4/0x660 fs/iomap/apply.c:46
 iomap_fiemap+0xd1/0x200 fs/iomap/fiemap.c:88
 _ext4_fiemap+0x36a/0x430 fs/ext4/extents.c:4860
 ext4_fiemap+0x36/0x50 fs/ext4/extents.c:4885
 ioctl_fiemap fs/ioctl.c:226 [inline]
 do_vfs_ioctl+0x5e1/0xd00 fs/ioctl.c:715
 ksys_ioctl+0xb2/0x150 fs/ioctl.c:761
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl fs/ioctl.c:770 [inline]
 __x64_sys_ioctl+0x47/0x60 fs/ioctl.c:770
 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: 0 PID: 19427 Comm: syz-executor.2 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/06/11 12:33 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 3ab7a05a .config console log report ci2-upstream-kcsan-gce
2020/05/12 14:40 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 a497a5b4 .config console log report ci2-upstream-kcsan-gce
2020/03/22 04:13 https://github.com/google/ktsan.git kcsan 40959e34d670 78267cec .config console log report ci2-upstream-kcsan-gce
2020/02/13 20:23 https://github.com/google/ktsan.git kcsan 55121bc1808a e6247653 .config console log report ci2-upstream-kcsan-gce
2020/02/11 10:50 https://github.com/google/ktsan.git kcsan f60f0f543333 084454ae .config console log report ci2-upstream-kcsan-gce
2020/02/06 00:00 https://github.com/google/ktsan.git kcsan 245a43005292 662cf49a .config console log report ci2-upstream-kcsan-gce
2019/12/31 07:52 https://github.com/google/ktsan.git kcsan 245a43005292 7f117e28 .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.