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KCSAN: data-race in ext4_set_iomap / writeback_single_inode

Status: closed as invalid on 2020/06/18 14:24
Subsystems: ext4
[Documentation on labels]
First crash: 1595d, last: 1424d
▶ ▼ Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in ext4_set_iomap / writeback_single_inode (2) ext4 76 1190d 1247d 0/26 auto-closed as invalid on 2021/03/08 23:38
upstream KCSAN: data-race in ext4_set_iomap / writeback_single_inode (3) ext4 44 941d 1148d 0/26 auto-closed as invalid on 2021/11/13 02:31

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

write to 0xffff8880b7eadb80 of 8 bytes by task 25960 on cpu 0:
 writeback_single_inode+0x1fc/0x2f0 fs/fs-writeback.c:1562
 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]
 ext4_buffered_write_iter+0x211/0x280 fs/ext4/file.c:277
 ext4_file_write_iter+0xf4/0xd30 fs/ext4/file.c:642
 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

read to 0xffff8880b7eadb80 of 8 bytes by task 25956 on cpu 1:
 ext4_inode_datasync_dirty fs/ext4/inode.c:3307 [inline]
 ext4_set_iomap+0x396/0x470 fs/ext4/inode.c:3322
 ext4_iomap_begin+0x3dc/0x4a0 fs/ext4/inode.c:3449
 iomap_apply+0xd4/0x660 fs/iomap/apply.c:46
 iomap_dio_rw+0x67e/0x9a0 fs/iomap/direct-io.c:498
 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]
 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

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 25956 Comm: syz-executor.4 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (13):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/06/13 10:37 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 f4724dd3 .config console log report ci2-upstream-kcsan-gce
2020/05/09 07:26 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 e97b06d3 .config console log report ci2-upstream-kcsan-gce
2020/04/22 05:19 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 2e44d63e .config console log report ci2-upstream-kcsan-gce
2020/04/12 03:05 https://github.com/google/ktsan.git kcsan 40959e34d670 a8c6a3f8 .config console log report ci2-upstream-kcsan-gce
2020/04/12 02:39 https://github.com/google/ktsan.git kcsan 40959e34d670 a8c6a3f8 .config console log report ci2-upstream-kcsan-gce
2020/03/28 23:48 https://github.com/google/ktsan.git kcsan 40959e34d670 05736b29 .config console log report ci2-upstream-kcsan-gce
2020/03/27 02:22 https://github.com/google/ktsan.git kcsan 40959e34d670 6d25c5a0 .config console log report ci2-upstream-kcsan-gce
2020/03/21 06:27 https://github.com/google/ktsan.git kcsan 40959e34d670 aa6c6a55 .config console log report ci2-upstream-kcsan-gce
2020/03/19 22:30 https://github.com/google/ktsan.git kcsan 40959e34d670 2c31c529 .config console log report ci2-upstream-kcsan-gce
2020/02/22 08:15 https://github.com/google/ktsan.git kcsan 766d004d1b85 2ffa6679 .config console log report ci2-upstream-kcsan-gce
2020/02/10 08:50 https://github.com/google/ktsan.git kcsan f60f0f543333 35f5e45e .config console log report ci2-upstream-kcsan-gce
2020/01/19 20:53 https://github.com/google/ktsan.git kcsan 245a43005292 0342f8c7 .config console log report ci2-upstream-kcsan-gce
2019/12/25 14:44 https://github.com/google/ktsan.git kcsan 245a43005292 be5c2c81 .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.