KCSAN: data-race in generic_file_read_iter / generic_write_end

Status: closed as invalid on 2020/06/18 14:24
Subsystems: ext4
[Documentation on labels]
First crash: 2463d, last: 2245d
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in generic_file_read_iter / generic_write_end (2) exfat 6 1 1116d 1116d 0/29 auto-obsoleted due to no activity on 2023/08/25 16:12

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

write to 0xffff88811d5977f8 of 8 bytes by task 11328 on cpu 1:
 i_size_write include/linux/fs.h:894 [inline]
 generic_write_end+0xd4/0x290 fs/buffer.c:2177
 ext4_da_write_end+0x162/0x690 fs/ext4/inode.c:3090
 generic_perform_write+0x1d7/0x320 mm/filemap.c:3313
 ext4_buffered_write_iter+0x14e/0x280 fs/ext4/file.c:270
 ext4_file_write_iter+0xf4/0xd30 fs/ext4/file.c:642
 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 0xffff88811d5977f8 of 8 bytes by task 11332 on cpu 0:
 generic_file_buffered_read mm/filemap.c:2091 [inline]
 generic_file_read_iter+0x85b/0x18c0 mm/filemap.c:2309
 ext4_file_read_iter fs/ext4/file.c:131 [inline]
 ext4_file_read_iter+0x103/0x360 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: 0 PID: 11332 Comm: syz-executor.3 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (17):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
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 10:54 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 4ea9d964 .config console log report ci2-upstream-kcsan-gce
2020/06/15 08:08 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 8e3ab941 .config console log report ci2-upstream-kcsan-gce
2020/06/14 11:23 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 2a22c77a .config console log report ci2-upstream-kcsan-gce
2020/06/12 04:28 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 819b58b0 .config console log report ci2-upstream-kcsan-gce
2020/06/07 21:56 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 7751efd0 .config console log report ci2-upstream-kcsan-gce
2020/06/04 01:10 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 b0d1c0d5 .config console log report ci2-upstream-kcsan-gce
2020/06/03 12:35 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 a5ce5de0 .config console log report ci2-upstream-kcsan-gce
2020/05/10 02:30 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 8742a2b9 .config console log report ci2-upstream-kcsan-gce
2020/05/05 12:25 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 4b76dd25 .config console log report ci2-upstream-kcsan-gce
2020/04/14 11:27 https://github.com/google/ktsan.git kcsan 40959e34d670 3f3c5574 .config console log report ci2-upstream-kcsan-gce
2020/03/25 16:52 https://github.com/google/ktsan.git kcsan 40959e34d670 e8e6c7d2 .config console log report ci2-upstream-kcsan-gce
2020/03/21 06:18 https://github.com/google/ktsan.git kcsan 40959e34d670 aa6c6a55 .config console log report ci2-upstream-kcsan-gce
2020/02/26 01:57 https://github.com/google/ktsan.git kcsan 766d004d1b85 4f588111 .config console log report ci2-upstream-kcsan-gce
2020/02/23 22:29 https://github.com/google/ktsan.git kcsan 766d004d1b85 d801cb02 .config console log report ci2-upstream-kcsan-gce
2020/01/19 15:44 https://github.com/google/ktsan.git kcsan 245a43005292 0342f8c7 .config console log report ci2-upstream-kcsan-gce
2019/11/12 08:21 https://github.com/google/ktsan.git kcsan 7f2955e0d056 048f2d49 .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.