KCSAN: data-race in ext4_setattr / generic_file_read_iter (2)

Status: closed as invalid on 2020/06/18 14:24
Subsystems: ext4
[Documentation on labels]
First crash: 2495d, last: 2315d
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in ext4_setattr / generic_file_read_iter ext4 6 2 2539d 2540d 0/29 closed as invalid on 2019/11/19 13:44

Sample crash report:
==================================================================
BUG: KCSAN: data-race in ext4_setattr / generic_file_read_iter

write to 0xffff8880b89e7738 of 8 bytes by task 13231 on cpu 1:
 i_size_write include/linux/fs.h:894 [inline]
 ext4_setattr+0xd58/0x1320 fs/ext4/inode.c:5365
 notify_change+0x82b/0xad0 fs/attr.c:336
 do_truncate+0xf9/0x180 fs/open.c:64
 handle_truncate fs/namei.c:2887 [inline]
 do_open fs/namei.c:3233 [inline]
 path_openat+0x1e51/0x23d0 fs/namei.c:3346
 do_filp_open+0x11e/0x1b0 fs/namei.c:3373
 do_sys_openat2+0x52e/0x680 fs/open.c:1148
 do_sys_open+0xa2/0x110 fs/open.c:1164
 ksys_open include/linux/syscalls.h:1386 [inline]
 __do_sys_creat fs/open.c:1232 [inline]
 __se_sys_creat fs/open.c:1230 [inline]
 __x64_sys_creat+0x42/0x60 fs/open.c:1230
 do_syscall_64+0xc7/0x3b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff8880b89e7738 of 8 bytes by task 13224 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: 13224 Comm: syz-executor.0 Not tainted 5.7.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (11):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/06/06 11:49 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 c3e9afb3 .config console log report ci2-upstream-kcsan-gce
2020/05/29 16:06 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 bed08304 .config console log report ci2-upstream-kcsan-gce
2020/05/11 09:25 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 f8f57555 .config console log report ci2-upstream-kcsan-gce
2020/05/06 09:42 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 35b8eb30 .config console log report ci2-upstream-kcsan-gce
2020/04/23 21:17 https://github.com/google/ktsan.git kcsan 7c3cd68e5d38 b9233cab .config console log report ci2-upstream-kcsan-gce
2020/04/14 00:12 https://github.com/google/ktsan.git kcsan 40959e34d670 7c54686a .config console log report ci2-upstream-kcsan-gce
2020/03/09 13:57 https://github.com/google/ktsan.git kcsan 941e0d917bbf 35f53e45 .config console log report ci2-upstream-kcsan-gce
2020/01/16 22:05 https://github.com/google/ktsan.git kcsan 245a43005292 3de7aabb .config console log report ci2-upstream-kcsan-gce
2020/01/11 01:08 https://github.com/google/ktsan.git kcsan 245a43005292 532ec44e .config console log report ci2-upstream-kcsan-gce
2019/12/12 01:32 https://github.com/google/ktsan.git kcsan ef798c30ba4e 0d368675 .config console log report ci2-upstream-kcsan-gce
2019/12/09 20:00 https://github.com/google/ktsan.git kcsan ef798c30ba4e b31eda3d .config console log report ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.