syzbot


KCSAN: data-race in ext4_file_write_iter / ext4_setattr (6)

Status: auto-closed as invalid on 2021/12/21 17:24
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 433d, last: 381d
similar bugs (6):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in ext4_file_write_iter / ext4_setattr (2) 1 726d 726d 0/24 auto-closed as invalid on 2021/01/11 11:39
upstream KCSAN: data-race in ext4_file_write_iter / ext4_setattr (3) 2 603d 604d 0/24 auto-closed as invalid on 2021/05/14 00:08
upstream KCSAN: data-race in ext4_file_write_iter / ext4_setattr (7) 1 303d 303d 0/24 auto-closed as invalid on 2022/03/09 13:22
upstream KCSAN: data-race in ext4_file_write_iter / ext4_setattr (4) 1 568d 568d 0/24 auto-closed as invalid on 2021/06/18 10:04
upstream KCSAN: data-race in ext4_file_write_iter / ext4_setattr 3 795d 818d 0/24 auto-closed as invalid on 2020/11/03 10:53
upstream KCSAN: data-race in ext4_file_write_iter / ext4_setattr (5) 3 476d 512d 0/24 auto-closed as invalid on 2021/09/18 07:46

Sample crash report:
==================================================================
BUG: KCSAN: data-race in ext4_file_write_iter / ext4_setattr

write to 0xffff88813cac2ac8 of 8 bytes by task 26146 on cpu 0:
 i_size_write include/linux/fs.h:913 [inline]
 ext4_setattr+0xd7e/0xf20 fs/ext4/inode.c:5451
 notify_change+0x8a3/0xac0 fs/attr.c:410
 do_truncate+0xf7/0x140 fs/open.c:64
 handle_truncate fs/namei.c:3082 [inline]
 do_open fs/namei.c:3430 [inline]
 path_openat+0x191f/0x1eb0 fs/namei.c:3559
 do_filp_open+0x105/0x220 fs/namei.c:3586
 do_sys_openat2+0xb5/0x2b0 fs/open.c:1212
 do_sys_open fs/open.c:1228 [inline]
 __do_sys_creat fs/open.c:1304 [inline]
 __se_sys_creat fs/open.c:1298 [inline]
 __x64_sys_creat+0x62/0x80 fs/open.c:1298
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88813cac2ac8 of 8 bytes by task 26122 on cpu 1:
 i_size_read include/linux/fs.h:891 [inline]
 ext4_dio_write_iter fs/ext4/file.c:495 [inline]
 ext4_file_write_iter+0x14b/0x1200 fs/ext4/file.c:679
 call_write_iter include/linux/fs.h:2162 [inline]
 do_iter_readv_writev+0x2de/0x380 fs/read_write.c:725
 do_iter_write+0x192/0x5c0 fs/read_write.c:851
 vfs_iter_write+0x4c/0x70 fs/read_write.c:892
 iter_file_splice_write+0x43a/0x790 fs/splice.c:689
 do_splice_from fs/splice.c:767 [inline]
 direct_splice_actor+0x80/0xa0 fs/splice.c:936
 splice_direct_to_actor+0x345/0x650 fs/splice.c:891
 do_splice_direct+0x106/0x190 fs/splice.c:979
 do_sendfile+0x675/0xc40 fs/read_write.c:1245
 __do_sys_sendfile64 fs/read_write.c:1310 [inline]
 __se_sys_sendfile64 fs/read_write.c:1296 [inline]
 __x64_sys_sendfile64+0x102/0x140 fs/read_write.c:1296
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000000000b0000 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 26122 Comm: syz-executor.2 Not tainted 5.16.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (8):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2021/11/16 17:18 upstream 8ab774587903 600426bd .config log report info KCSAN: data-race in ext4_file_write_iter / ext4_setattr
ci2-upstream-kcsan-gce 2021/11/15 13:43 upstream 8ab774587903 75b04091 .config log report info KCSAN: data-race in ext4_file_write_iter / ext4_setattr
ci2-upstream-kcsan-gce 2021/10/30 05:24 upstream a379fbbcb88b 098b5d53 .config log report info KCSAN: data-race in ext4_file_write_iter / ext4_setattr
ci2-upstream-kcsan-gce 2021/10/21 13:03 upstream 2f111a6fd5b5 f111d03b .config log report info KCSAN: data-race in ext4_file_write_iter / ext4_setattr
ci2-upstream-kcsan-gce 2021/10/11 01:07 upstream efb52a7d9511 838e7e2c .config log report info KCSAN: data-race in ext4_file_write_iter / ext4_setattr
ci2-upstream-kcsan-gce 2021/10/06 04:03 upstream 60a9483534ed 0a63fd36 .config log report info KCSAN: data-race in ext4_file_write_iter / ext4_setattr
ci2-upstream-kcsan-gce 2021/09/29 03:19 upstream d33bec7b3dfa d82cb927 .config log report info KCSAN: data-race in ext4_file_write_iter / ext4_setattr
ci2-upstream-kcsan-gce 2021/09/25 22:43 upstream 85736168463d 8cac236e .config log report info KCSAN: data-race in ext4_file_write_iter / ext4_setattr
* Struck through repros no longer work on HEAD.