syzbot


KCSAN: data-race in copy_page_to_iter / ext4_setup_super (3)

Status: auto-closed as invalid on 2021/12/28 03:51
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 375d, last: 375d
similar bugs (3):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in copy_page_to_iter / ext4_setup_super (4) 1 205d 205d 0/24 closed as invalid on 2022/05/13 11:20
upstream KCSAN: data-race in copy_page_to_iter / ext4_setup_super 2 578d 583d 0/24 auto-closed as invalid on 2021/06/08 06:58
upstream KCSAN: data-race in copy_page_to_iter / ext4_setup_super (2) 2 460d 520d 0/24 auto-closed as invalid on 2021/10/04 04:01

Sample crash report:
==================================================================
BUG: KCSAN: data-race in copy_page_to_iter / ext4_setup_super

write to 0xffff888134ec243a of 2 bytes by task 5537 on cpu 0:
 ext4_setup_super+0x246/0x620 fs/ext4/super.c:2694
 ext4_fill_super+0x58c3/0x78f0 fs/ext4/super.c:4842
 mount_bdev+0x1e8/0x290 fs/super.c:1370
 ext4_mount+0x2d/0x40 fs/ext4/super.c:6523
 legacy_get_tree+0x70/0xc0 fs/fs_context.c:610
 vfs_get_tree+0x4a/0x1a0 fs/super.c:1500
 do_new_mount fs/namespace.c:2988 [inline]
 path_mount+0x11cf/0x1c40 fs/namespace.c:3318
 do_mount fs/namespace.c:3331 [inline]
 __do_sys_mount fs/namespace.c:3539 [inline]
 __se_sys_mount+0x24b/0x2f0 fs/namespace.c:3516
 __x64_sys_mount+0x63/0x70 fs/namespace.c:3516
 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 0xffff888134ec2400 of 1024 bytes by task 1982 on cpu 1:
 instrument_copy_to_user include/linux/instrumented.h:119 [inline]
 copyout lib/iov_iter.c:156 [inline]
 copy_page_to_iter_iovec lib/iov_iter.c:228 [inline]
 __copy_page_to_iter lib/iov_iter.c:852 [inline]
 copy_page_to_iter+0x2cb/0x950 lib/iov_iter.c:880
 filemap_read+0x138b/0x16d0 mm/filemap.c:2697
 generic_file_read_iter+0x72/0x2a0 mm/filemap.c:2792
 blkdev_read_iter+0x96/0x140 block/fops.c:583
 call_read_iter include/linux/fs.h:2156 [inline]
 new_sync_read fs/read_write.c:400 [inline]
 vfs_read+0x66c/0x750 fs/read_write.c:481
 ksys_read+0xd9/0x190 fs/read_write.c:619
 __do_sys_read fs/read_write.c:629 [inline]
 __se_sys_read fs/read_write.c:627 [inline]
 __x64_sys_read+0x3e/0x50 fs/read_write.c:627
 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

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 1982 Comm: udevd Not tainted 5.16.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2021/11/23 03:47 upstream 136057256686 545ab074 .config log report info KCSAN: data-race in copy_page_to_iter / ext4_setup_super
* Struck through repros no longer work on HEAD.