Module Name: src
Committed By: maxv
Date: Wed Feb 26 18:00:12 UTC 2020
Modified Files:
src/sys/ufs/ufs: ufs_vnops.c
Log Message:
Zero out the padding in 'd_namlen', to prevent info leaks. Same logic as
ufs_makedirentry().
Found by kMSan: the unzeroed bytes of the pool_cache were getting copied
to the disk via a DMA write operation, and there kMSan was noticing
uninitialized memory leaving the system.
Reported-by: syzbot+382c9dffc06a9683a...@syzkaller.appspotmail.com
To generate a diff of this commit:
cvs rdiff -u -r1.248 -r1.249 src/sys/ufs/ufs/ufs_vnops.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/ufs/ufs/ufs_vnops.c
diff -u src/sys/ufs/ufs/ufs_vnops.c:1.248 src/sys/ufs/ufs/ufs_vnops.c:1.249
--- src/sys/ufs/ufs/ufs_vnops.c:1.248 Wed Sep 18 17:59:15 2019
+++ src/sys/ufs/ufs/ufs_vnops.c Wed Feb 26 18:00:12 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: ufs_vnops.c,v 1.248 2019/09/18 17:59:15 christos Exp $ */
+/* $NetBSD: ufs_vnops.c,v 1.249 2020/02/26 18:00:12 maxv Exp $ */
/*-
* Copyright (c) 2008 The NetBSD Foundation, Inc.
@@ -66,7 +66,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ufs_vnops.c,v 1.248 2019/09/18 17:59:15 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ufs_vnops.c,v 1.249 2020/02/26 18:00:12 maxv Exp $");
#if defined(_KERNEL_OPT)
#include "opt_ffs.h"
@@ -873,7 +873,11 @@ ufs_whiteout(void *v)
newdir->d_namlen = cnp->cn_namelen;
memcpy(newdir->d_name, cnp->cn_nameptr,
(size_t)cnp->cn_namelen);
- newdir->d_name[cnp->cn_namelen] = '\0';
+
+ /* NUL terminate and zero out padding */
+ memset(&newdir->d_name[cnp->cn_namelen], 0,
+ UFS_NAMEPAD(cnp->cn_namelen));
+
newdir->d_type = DT_WHT;
error = ufs_direnter(dvp, ulr, NULL, newdir, cnp, NULL);
pool_cache_put(ufs_direct_cache, newdir);
