syzbot


KCSAN: data-race in ext4_file_write_iter / ext4_setattr (5)

Status: auto-closed as invalid on 2021/09/18 07:46
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 510d, last: 473d
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 723d 723d 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 601d 601d 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 301d 301d 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 565d 565d 0/24 auto-closed as invalid on 2021/06/18 10:04
upstream KCSAN: data-race in ext4_file_write_iter / ext4_setattr 3 792d 816d 0/24 auto-closed as invalid on 2020/11/03 10:53
upstream KCSAN: data-race in ext4_file_write_iter / ext4_setattr (6) 8 379d 431d 0/24 auto-closed as invalid on 2021/12/21 17:24

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

write to 0xffff888106bb1190 of 8 bytes by task 28989 on cpu 0:
 i_size_write include/linux/fs.h:871 [inline]
 ext4_setattr+0xd54/0xec0 fs/ext4/inode.c:5481
 notify_change+0x8a3/0xa80 fs/attr.c:398
 do_truncate fs/open.c:64 [inline]
 vfs_truncate+0x2ff/0x470 fs/open.c:112
 do_sys_truncate fs/open.c:135 [inline]
 __do_sys_truncate fs/open.c:147 [inline]
 __se_sys_truncate fs/open.c:145 [inline]
 __x64_sys_truncate+0xa0/0x120 fs/open.c:145
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888106bb1190 of 8 bytes by task 28960 on cpu 1:
 i_size_read include/linux/fs.h:849 [inline]
 ext4_dio_write_iter fs/ext4/file.c:495 [inline]
 ext4_file_write_iter+0x14c/0x11d0 fs/ext4/file.c:678
 call_write_iter include/linux/fs.h:2114 [inline]
 do_iter_readv_writev+0x2cb/0x360 fs/read_write.c:740
 do_iter_write+0x112/0x4c0 fs/read_write.c:866
 vfs_iter_write+0x4c/0x70 fs/read_write.c:907
 iter_file_splice_write+0x40a/0x750 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+0xf5/0x170 fs/splice.c:979
 do_sendfile+0x773/0xda0 fs/read_write.c:1260
 __do_sys_sendfile64 fs/read_write.c:1325 [inline]
 __se_sys_sendfile64 fs/read_write.c:1311 [inline]
 __x64_sys_sendfile64+0xf2/0x130 fs/read_write.c:1311
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x0000000000190000 -> 0x0000000000000ff6

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 28960 Comm: syz-executor.1 Tainted: G        W         5.14.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (3):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2021/08/14 07:40 upstream dfa377c35d70 2489ab88 .config log report info KCSAN: data-race in ext4_file_write_iter / ext4_setattr
ci2-upstream-kcsan-gce 2021/07/22 05:30 upstream 7b6ae471e541 29c3f20f .config log report info KCSAN: data-race in ext4_file_write_iter / ext4_setattr
ci2-upstream-kcsan-gce 2021/07/08 18:42 upstream 3dbdb38e2869 1b20171a .config log report info KCSAN: data-race in ext4_file_write_iter / ext4_setattr
* Struck through repros no longer work on HEAD.