syzbot


KCSAN: data-race in copy_page_to_iter / ext4_xattr_set_handle

Status: auto-closed as invalid on 2021/12/07 21:37
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 400d, last: 400d

Sample crash report:
==================================================================
BUG: KCSAN: data-race in copy_page_to_iter / ext4_xattr_set_handle

write to 0xffff88813177d45c of 4 bytes by task 4505 on cpu 0:
 ext4_set_feature_xattr fs/ext4/ext4.h:2095 [inline]
 ext4_xattr_update_super_block fs/ext4/xattr.c:797 [inline]
 ext4_xattr_set_handle+0xeb9/0x1120 fs/ext4/xattr.c:2398
 ext4_initxattrs+0x66/0xb0 fs/ext4/xattr_security.c:44
 security_inode_init_security+0x1a9/0x260 security/security.c:1100
 ext4_init_security+0x30/0x40 fs/ext4/xattr_security.c:58
 __ext4_new_inode+0x29a3/0x2fc0 fs/ext4/ialloc.c:1325
 ext4_create+0x18c/0x320 fs/ext4/namei.c:2746
 lookup_open fs/namei.c:3280 [inline]
 open_last_lookups fs/namei.c:3350 [inline]
 path_openat+0xd2c/0x1eb0 fs/namei.c:3556
 do_filp_open+0x105/0x220 fs/namei.c:3586
 do_sys_openat2+0xb5/0x2b0 fs/open.c:1200
 do_sys_open fs/open.c:1216 [inline]
 __do_sys_open fs/open.c:1224 [inline]
 __se_sys_open fs/open.c:1220 [inline]
 __x64_sys_open+0xe2/0x110 fs/open.c:1220
 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 0xffff88813177d400 of 1024 bytes by task 3169 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+0x140b/0x1720 mm/filemap.c:2679
 generic_file_read_iter+0x75/0x2c0 mm/filemap.c:2775
 blkdev_read_iter+0x98/0x140 block/fops.c:583
 call_read_iter include/linux/fs.h:2155 [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+0x44/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 3169 Comm: udevd Not tainted 5.15.0-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 2021/11/02 21:27 upstream bfc484fe6abb 17f3edd2 .config log report info KCSAN: data-race in copy_page_to_iter / ext4_xattr_set_handle
* Struck through repros no longer work on HEAD.