syzbot


KCSAN: data-race in copy_page_to_iter / ext4_mark_iloc_dirty (2)

Status: auto-closed as invalid on 2021/11/05 18:49
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 421d, last: 420d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in copy_page_to_iter / ext4_mark_iloc_dirty 1 457d 457d 0/24 auto-closed as invalid on 2021/09/30 09:26

Sample crash report:
==================================================================
BUG: KCSAN: data-race in copy_page_to_iter / ext4_mark_iloc_dirty

write to 0xffff88812d11001c of 4 bytes by task 30360 on cpu 0:
 ext4_inode_blocks_set fs/ext4/inode.c:4929 [inline]
 ext4_do_update_inode fs/ext4/inode.c:5051 [inline]
 ext4_mark_iloc_dirty+0x233/0x1700 fs/ext4/inode.c:5741
 __ext4_mark_inode_dirty+0x4ec/0x5c0 fs/ext4/inode.c:5937
 ext4_alloc_file_blocks+0x65c/0x730 fs/ext4/extents.c:4443
 ext4_fallocate+0x2a7/0x4d0 fs/ext4/extents.c:4718
 vfs_fallocate+0x459/0x6a0 fs/open.c:307
 do_vfs_ioctl+0x13c6/0x14c0 fs/ioctl.c:853
 __do_sys_ioctl fs/ioctl.c:872 [inline]
 __se_sys_ioctl+0x83/0x140 fs/ioctl.c:860
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88812d110000 of 1024 bytes by task 30359 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:805 [inline]
 copy_page_to_iter+0x2cb/0x950 lib/iov_iter.c:833
 filemap_read+0xee6/0x1220 mm/filemap.c:2683
 generic_file_read_iter+0x75/0x2c0 mm/filemap.c:2779
 blkdev_read_iter+0xb9/0xf0 block/fops.c:545
 call_read_iter include/linux/fs.h:2157 [inline]
 new_sync_read fs/read_write.c:404 [inline]
 vfs_read+0x66c/0x750 fs/read_write.c:485
 ksys_read+0xd9/0x190 fs/read_write.c:623
 __do_sys_read fs/read_write.c:633 [inline]
 __se_sys_read fs/read_write.c:631 [inline]
 __x64_sys_read+0x3e/0x50 fs/read_write.c:631
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 30359 Comm: systemd-udevd Not tainted 5.15.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2021/10/01 18:48 upstream 24f67d82c43c cc80db95 .config log report info KCSAN: data-race in copy_page_to_iter / ext4_mark_iloc_dirty
ci2-upstream-kcsan-gce 2021/09/30 22:09 upstream 4de593fb965f 0f01403d .config log report info KCSAN: data-race in copy_page_to_iter / ext4_mark_iloc_dirty
* Struck through repros no longer work on HEAD.