syzbot


KCSAN: data-race in copy_page_to_iter / ext4_setup_super (4)

Status: closed as invalid on 2022/05/13 11:20
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 205d, last: 205d
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 (3) 1 375d 375d 0/24 auto-closed as invalid on 2021/12/28 03:51
upstream KCSAN: data-race in copy_page_to_iter / ext4_setup_super 2 577d 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

read-write to 0xffff8881411d043a of 2 bytes by task 16114 on cpu 0:
 ext4_setup_super+0x237/0x5c0 fs/ext4/super.c:3153
 __ext4_fill_super fs/ext4/super.c:5346 [inline]
 ext4_fill_super+0x432a/0x4eb0 fs/ext4/super.c:5603
 get_tree_bdev+0x2b4/0x3b0 fs/super.c:1292
 ext4_get_tree+0x18/0x20 fs/ext4/super.c:5633
 vfs_get_tree+0x49/0x190 fs/super.c:1497
 do_new_mount+0x200/0x650 fs/namespace.c:3040
 path_mount+0x4b1/0xb60 fs/namespace.c:3370
 do_mount fs/namespace.c:3383 [inline]
 __do_sys_mount fs/namespace.c:3591 [inline]
 __se_sys_mount+0x281/0x2d0 fs/namespace.c:3568
 __x64_sys_mount+0x63/0x70 fs/namespace.c:3568
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881411d0400 of 1024 bytes by task 12699 on cpu 1:
 instrument_copy_to_user include/linux/instrumented.h:119 [inline]
 copyout lib/iov_iter.c:154 [inline]
 copy_page_to_iter_iovec lib/iov_iter.c:226 [inline]
 __copy_page_to_iter lib/iov_iter.c:852 [inline]
 copy_page_to_iter+0x415/0x7b0 lib/iov_iter.c:880
 copy_folio_to_iter include/linux/uio.h:153 [inline]
 filemap_read+0x10b2/0x1400 mm/filemap.c:2730
 blkdev_read_iter+0x2c6/0x370 block/fops.c:611
 call_read_iter include/linux/fs.h:2044 [inline]
 new_sync_read fs/read_write.c:401 [inline]
 vfs_read+0x5a5/0x6a0 fs/read_write.c:482
 ksys_read+0xe8/0x1a0 fs/read_write.c:620
 __do_sys_read fs/read_write.c:630 [inline]
 __se_sys_read fs/read_write.c:628 [inline]
 __x64_sys_read+0x3e/0x50 fs/read_write.c:628
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 12699 Comm: udevd Not tainted 5.18.0-rc6-syzkaller-00009-gfeb9c5e19e91 #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 2022/05/12 00:38 upstream feb9c5e19e91 beb0b407 .config log report info KCSAN: data-race in copy_page_to_iter / ext4_setup_super
* Struck through repros no longer work on HEAD.