[PATCH 1/2] iscsi-target: clean up sysfs string store() macros.

[Eric Seppanen <eric@xxxxxxxxxxxxxxx>]

The iSCSI CHAP authentication username and password are stored into
a buffer that's smaller than a page, so use strlcpy() to copy the
incoming string, and add strim() to strip any trailing newline.
Return -EINVAL if the incoming string wouldn't fit in the buffer.

Signed-off-by: Eric Seppanen <eric@xxxxxxxxxxxxxxx>
---
 drivers/target/iscsi/iscsi_target_configfs.c |   31 ++++++++++++++------------
 1 file changed, 17 insertions(+), 14 deletions(-)

diff --git a/drivers/target/iscsi/iscsi_target_configfs.c b/drivers/target/iscsi/iscsi_target_configfs.c
index 8d8b3ff..23d02ce 100644
--- a/drivers/target/iscsi/iscsi_target_configfs.c
+++ b/drivers/target/iscsi/iscsi_target_configfs.c
@@ -452,7 +452,7 @@ static struct configfs_attribute *lio_target_nacl_attrib_attrs[] = {
 
 /* Start items for lio_target_nacl_auth_cit */
 
-#define __DEF_NACL_AUTH_STR(prefix, name, flags)			\
+#define __DEF_NACL_AUTH_STR(prefix, name, maxlen, flags)		\
 static ssize_t __iscsi_##prefix##_show_##name(				\
 	struct iscsi_node_acl *nacl,					\
 	char *page)							\
@@ -474,7 +474,10 @@ static ssize_t __iscsi_##prefix##_store_##name(				\
 	if (!capable(CAP_SYS_ADMIN))					\
 		return -EPERM;						\
 									\
-	snprintf(auth->name, PAGE_SIZE, "%s", page);			\
+	if (count >= maxlen)						\
+		return -EINVAL;						\
+	strlcpy(auth->name, page, maxlen);				\
+	strim(auth->name);						\
 	if (!strncmp("NULL", auth->name, 4))				\
 		auth->naf_flags &= ~flags;				\
 	else								\
@@ -502,8 +505,8 @@ static ssize_t __iscsi_##prefix##_show_##name(				\
 	return snprintf(page, PAGE_SIZE, "%d\n", auth->name);		\
 }
 
-#define DEF_NACL_AUTH_STR(name, flags)					\
-	__DEF_NACL_AUTH_STR(nacl_auth, name, flags)			\
+#define DEF_NACL_AUTH_STR(name, maxlen, flags)				\
+	__DEF_NACL_AUTH_STR(nacl_auth, name, maxlen, flags)		\
 static ssize_t iscsi_nacl_auth_show_##name(				\
 	struct se_node_acl *nacl,					\
 	char *page)							\
@@ -536,12 +539,12 @@ static ssize_t iscsi_nacl_auth_show_##name(				\
 /*
  * One-way authentication userid
  */
-DEF_NACL_AUTH_STR(userid, NAF_USERID_SET);
+DEF_NACL_AUTH_STR(userid, MAX_USER_LEN, NAF_USERID_SET);
 AUTH_ATTR(userid, S_IRUGO | S_IWUSR);
 /*
  * One-way authentication password
  */
-DEF_NACL_AUTH_STR(password, NAF_PASSWORD_SET);
+DEF_NACL_AUTH_STR(password, MAX_PASS_LEN, NAF_PASSWORD_SET);
 AUTH_ATTR(password, S_IRUGO | S_IWUSR);
 /*
  * Enforce mutual authentication
@@ -551,12 +554,12 @@ AUTH_ATTR_RO(authenticate_target);
 /*
  * Mutual authentication userid
  */
-DEF_NACL_AUTH_STR(userid_mutual, NAF_USERID_IN_SET);
+DEF_NACL_AUTH_STR(userid_mutual, MAX_USER_LEN, NAF_USERID_IN_SET);
 AUTH_ATTR(userid_mutual, S_IRUGO | S_IWUSR);
 /*
  * Mutual authentication password
  */
-DEF_NACL_AUTH_STR(password_mutual, NAF_PASSWORD_IN_SET);
+DEF_NACL_AUTH_STR(password_mutual, MAX_PASS_LEN, NAF_PASSWORD_IN_SET);
 AUTH_ATTR(password_mutual, S_IRUGO | S_IWUSR);
 
 static struct configfs_attribute *lio_target_nacl_auth_attrs[] = {
@@ -1430,8 +1433,8 @@ static void lio_target_call_coredeltiqn(
 
 /* Start lio_target_discovery_auth_cit */
 
-#define DEF_DISC_AUTH_STR(name, flags)					\
-	__DEF_NACL_AUTH_STR(disc, name, flags)				\
+#define DEF_DISC_AUTH_STR(name, maxlen, flags)				\
+	__DEF_NACL_AUTH_STR(disc, name, maxlen, flags)			\
 static ssize_t iscsi_disc_show_##name(					\
 	struct target_fabric_configfs *tf,				\
 	char *page)							\
@@ -1464,12 +1467,12 @@ static ssize_t iscsi_disc_show_##name(					\
 /*
  * One-way authentication userid
  */
-DEF_DISC_AUTH_STR(userid, NAF_USERID_SET);
+DEF_DISC_AUTH_STR(userid, MAX_USER_LEN, NAF_USERID_SET);
 DISC_AUTH_ATTR(userid, S_IRUGO | S_IWUSR);
 /*
  * One-way authentication password
  */
-DEF_DISC_AUTH_STR(password, NAF_PASSWORD_SET);
+DEF_DISC_AUTH_STR(password, MAX_PASS_LEN, NAF_PASSWORD_SET);
 DISC_AUTH_ATTR(password, S_IRUGO | S_IWUSR);
 /*
  * Enforce mutual authentication
@@ -1479,12 +1482,12 @@ DISC_AUTH_ATTR_RO(authenticate_target);
 /*
  * Mutual authentication userid
  */
-DEF_DISC_AUTH_STR(userid_mutual, NAF_USERID_IN_SET);
+DEF_DISC_AUTH_STR(userid_mutual, MAX_USER_LEN, NAF_USERID_IN_SET);
 DISC_AUTH_ATTR(userid_mutual, S_IRUGO | S_IWUSR);
 /*
  * Mutual authentication password
  */
-DEF_DISC_AUTH_STR(password_mutual, NAF_PASSWORD_IN_SET);
+DEF_DISC_AUTH_STR(password_mutual, MAX_PASS_LEN, NAF_PASSWORD_IN_SET);
 DISC_AUTH_ATTR(password_mutual, S_IRUGO | S_IWUSR);
 
 /*
-- 
1.7.10.4

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