From: Al Viro <viro@zeniv.linux.org.uk>

Date: Fri, 5 Mar 2021 15:02:34 -0500

Subject: [PATCH] cifs: don't cargo-cult strndup()

Git-commit: 8d7672235533dbeab4a5373b49f1b4273cdc2c6a

References: bsc#1185902

Patch-mainline: v5.13-rc1

strndup(s, strlen(s)) is a highly unidiomatic way to spell strdup(s);

it's *NOT* safer in any way, since strlen() is just as sensitive to

NUL-termination as strdup() is.

strndup() is for situations when you need a copy of a known-sized

substring, not a magic security juju to drive the bad spirits away.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Signed-off-by: Steve French <stfrench@microsoft.com>

Acked-by: Paulo Alcantara <palcantara@suse.de>

---

 fs/cifs/cifs_dfs_ref.c |    2 +-

 fs/cifs/connect.c      |    8 +++-----

 fs/cifs/dfs_cache.c    |   18 +++++++++---------

 fs/cifs/misc.c         |    2 +-

 fs/cifs/smb1ops.c      |    4 +---

 5 files changed, 15 insertions(+), 19 deletions(-)

--- a/fs/cifs/cifs_dfs_ref.c

+++ b/fs/cifs/cifs_dfs_ref.c

@@ -272,7 +272,7 @@ static struct vfsmount *cifs_dfs_do_moun

 	char *mountdata;

 	char *devname;

-	devname = kstrndup(fullpath, strlen(fullpath), GFP_KERNEL);

+	devname = kstrdup(fullpath, GFP_KERNEL);

 	if (!devname)

 		return ERR_PTR(-ENOMEM);

--- a/fs/cifs/connect.c

+++ b/fs/cifs/connect.c

@@ -3150,9 +3150,7 @@ cifs_set_cifscreds(struct smb_vol *vol,

 	 * for the request.

 	 */

 	if (is_domain && ses->domainName) {

-		vol->domainname = kstrndup(ses->domainName,

-					   strlen(ses->domainName),

-					   GFP_KERNEL);

+		vol->domainname = kstrdup(ses->domainName, GFP_KERNEL);

 		if (!vol->domainname) {

 			cifs_dbg(FYI, "Unable to allocate %zd bytes for "

 				 "domain\n", len);

@@ -4804,7 +4802,7 @@ int cifs_mount(struct cifs_sb_info *cifs

 			goto error;

 	}

 	/* Save mount options */

-	mntdata = kstrndup(cifs_sb->mountdata, strlen(cifs_sb->mountdata), GFP_KERNEL);

+	mntdata = kstrdup(cifs_sb->mountdata, GFP_KERNEL);

 	if (!mntdata) {

 		rc = -ENOMEM;

 		goto error;

@@ -4877,7 +4875,7 @@ int cifs_mount(struct cifs_sb_info *cifs

 	 * links, the prefix path is included in both and may be changed during reconnect.  See

 	 * cifs_tree_connect().

 	 */

-	cifs_sb->origin_fullpath = kstrndup(full_path, strlen(full_path), GFP_KERNEL);

+	cifs_sb->origin_fullpath = kstrdup(full_path, GFP_KERNEL);

 	if (!cifs_sb->origin_fullpath) {

 		rc = -ENOMEM;

 		goto error;

--- a/fs/cifs/dfs_cache.c

+++ b/fs/cifs/dfs_cache.c

@@ -87,7 +87,7 @@ static int get_normalized_path(const cha

 	if (*path == '\\') {

 		*npath = (char *)path;

 	} else {

-		*npath = kstrndup(path, strlen(path), GFP_KERNEL);

+		*npath = kstrdup(path, GFP_KERNEL);

 		if (!*npath)

 			return -ENOMEM;

 		convert_delimiter(*npath, '\\');

@@ -354,7 +354,7 @@ static struct cache_dfs_tgt *alloc_targe

 	t = kmalloc(sizeof(*t), GFP_ATOMIC);

 	if (!t)

 		return ERR_PTR(-ENOMEM);

-	t->name = kstrndup(name, strlen(name), GFP_ATOMIC);

+	t->name = kstrdup(name, GFP_ATOMIC);

 	if (!t->name) {

 		kfree(t);

 		return ERR_PTR(-ENOMEM);

@@ -415,7 +415,7 @@ static struct cache_entry *alloc_cache_e

 	if (!ce)

 		return ERR_PTR(-ENOMEM);

-	ce->path = kstrndup(path, strlen(path), GFP_KERNEL);

+	ce->path = kstrdup(path, GFP_KERNEL);

 	if (!ce->path) {

 		kmem_cache_free(cache_slab, ce);

 		return ERR_PTR(-ENOMEM);

@@ -527,7 +527,7 @@ static struct cache_entry *lookup_cache_

 	char *s, *e;

 	char sep;

-	npath = kstrndup(path, strlen(path), GFP_KERNEL);

+	npath = kstrdup(path, GFP_KERNEL);

 	if (!npath)

 		return ERR_PTR(-ENOMEM);

@@ -637,7 +637,7 @@ static int __update_cache_entry(const ch

 	if (ce->tgthint) {

 		s = ce->tgthint->name;

-		th = kstrndup(s, strlen(s), GFP_ATOMIC);

+		th = kstrdup(s, GFP_ATOMIC);

 		if (!th)

 			return -ENOMEM;

 	}

@@ -782,11 +782,11 @@ static int setup_referral(const char *pa

 	memset(ref, 0, sizeof(*ref));

-	ref->path_name = kstrndup(path, strlen(path), GFP_ATOMIC);

+	ref->path_name = kstrdup(path, GFP_ATOMIC);

 	if (!ref->path_name)

 		return -ENOMEM;

-	ref->node_name = kstrndup(target, strlen(target), GFP_ATOMIC);

+	ref->node_name = kstrdup(target, GFP_ATOMIC);

 	if (!ref->node_name) {

 		rc = -ENOMEM;

 		goto err_free_path;

@@ -824,7 +824,7 @@ static int get_targets(struct cache_entr

 			goto err_free_it;

 		}

-		it->it_name = kstrndup(t->name, strlen(t->name), GFP_ATOMIC);

+		it->it_name = kstrdup(t->name, GFP_ATOMIC);

 		if (!it->it_name) {

 			kfree(it);

 			rc = -ENOMEM;

@@ -1220,7 +1220,7 @@ int dfs_cache_add_vol(char *mntdata, str

 	if (!vi)

 		return -ENOMEM;

-	vi->fullpath = kstrndup(fullpath, strlen(fullpath), GFP_KERNEL);

+	vi->fullpath = kstrdup(fullpath, GFP_KERNEL);

 	if (!vi->fullpath) {

 		rc = -ENOMEM;

 		goto err_free_vi;

--- a/fs/cifs/misc.c

+++ b/fs/cifs/misc.c

@@ -1182,7 +1182,7 @@ int update_super_prepath(struct cifs_tco

 	kfree(cifs_sb->prepath);

 	if (prefix && *prefix) {

-		cifs_sb->prepath = kstrndup(prefix, strlen(prefix), GFP_ATOMIC);

+		cifs_sb->prepath = kstrdup(prefix, GFP_ATOMIC);

 		if (!cifs_sb->prepath) {

 			rc = -ENOMEM;

 			goto out;

--- a/fs/cifs/smb1ops.c

+++ b/fs/cifs/smb1ops.c

@@ -925,9 +925,7 @@ cifs_unix_dfs_readlink(const unsigned in

 			  0);

 	if (!rc) {

-		*symlinkinfo = kstrndup(referral.node_name,

-					strlen(referral.node_name),

-					GFP_KERNEL);

+		*symlinkinfo = kstrdup(referral.node_name, GFP_KERNEL);

 		free_dfs_info_param(&referral);

 		if (!*symlinkinfo)

 			rc = -ENOMEM;