From: Vitaly Kuznetsov <vkuznets@redhat.com>

Date: Sun, 30 Apr 2017 16:21:15 -0700

Patch-mainline: v4.13-rc1

Subject: tools: hv: properly handle long paths

Git-commit: a1a7ea6bd6d55b6620c9c0a43bf684d6c427172a

References: fate#323887

Paths can be up to PATH_MAX long and PATH_MAX is usually greater than 256.

While on it, simplify path reconstruction to a simple snprintf(), define

and reuse KVP_NET_DIR.

Suggested-by: Tomas Hozza <thozza@redhat.com>

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Acked-by: Olaf Hering <ohering@suse.de>

---

 tools/hv/hv_kvp_daemon.c | 44 ++++++++++++++++++--------------------------

 1 file changed, 18 insertions(+), 26 deletions(-)

diff --git a/tools/hv/hv_kvp_daemon.c b/tools/hv/hv_kvp_daemon.c

--- a/tools/hv/hv_kvp_daemon.c

+++ b/tools/hv/hv_kvp_daemon.c

@@ -39,6 +39,7 @@

 #include <fcntl.h>

 #include <dirent.h>

 #include <net/if.h>

+#include <limits.h>

 #include <getopt.h>

 /*

@@ -97,6 +98,8 @@ static struct utsname uts_buf;

 #define KVP_SCRIPTS_PATH "/usr/libexec/hypervkvpd/"

 #endif

+#define KVP_NET_DIR "/sys/class/net/"

+

 #define MAX_FILE_NAME 100

 #define ENTRIES_PER_BLOCK 50

@@ -596,26 +599,21 @@ static char *kvp_get_if_name(char *guid)

 	DIR *dir;

 	struct dirent *entry;

 	FILE    *file;

-	char    *p, *q, *x;

+	char    *p, *x;

 	char    *if_name = NULL;

 	char    buf[256];

-	char *kvp_net_dir = "/sys/class/net/";

-	char dev_id[256];

+	char dev_id[PATH_MAX];

-	dir = opendir(kvp_net_dir);

+	dir = opendir(KVP_NET_DIR);

 	if (dir == NULL)

 		return NULL;

-	snprintf(dev_id, sizeof(dev_id), "%s", kvp_net_dir);

-	q = dev_id + strlen(kvp_net_dir);

-

 	while ((entry = readdir(dir)) != NULL) {

 		/*

 		 * Set the state for the next pass.

 		 */

-		*q = '\0';

-		strcat(dev_id, entry->d_name);

-		strcat(dev_id, "/device/device_id");

+		snprintf(dev_id, sizeof(dev_id), "%s%s/device/device_id",

+			 KVP_NET_DIR, entry->d_name);

 		file = fopen(dev_id, "r");

 		if (file == NULL)

@@ -653,12 +651,12 @@ static char *kvp_if_name_to_mac(char *if_name)

 	FILE    *file;

 	char    *p, *x;

 	char    buf[256];

-	char addr_file[256];

+	char addr_file[PATH_MAX];

 	unsigned int i;

 	char *mac_addr = NULL;

-	snprintf(addr_file, sizeof(addr_file), "%s%s%s", "/sys/class/net/",

-		if_name, "/address");

+	snprintf(addr_file, sizeof(addr_file), "%s%s%s", KVP_NET_DIR,

+		 if_name, "/address");

 	file = fopen(addr_file, "r");

 	if (file == NULL)

@@ -688,28 +686,22 @@ static char *kvp_mac_to_if_name(char *mac)

 	DIR *dir;

 	struct dirent *entry;

 	FILE    *file;

-	char    *p, *q, *x;

+	char    *p, *x;

 	char    *if_name = NULL;

 	char    buf[256];

-	char *kvp_net_dir = "/sys/class/net/";

-	char dev_id[256];

+	char dev_id[PATH_MAX];

 	unsigned int i;

-	dir = opendir(kvp_net_dir);

+	dir = opendir(KVP_NET_DIR);

 	if (dir == NULL)

 		return NULL;

-	snprintf(dev_id, sizeof(dev_id), "%s", kvp_net_dir);

-	q = dev_id + strlen(kvp_net_dir);

-

 	while ((entry = readdir(dir)) != NULL) {

 		/*

 		 * Set the state for the next pass.

 		 */

-		*q = '\0';

-

-		strcat(dev_id, entry->d_name);

-		strcat(dev_id, "/address");

+		snprintf(dev_id, sizeof(dev_id), "%s%s/address", KVP_NET_DIR,

+			 entry->d_name);

 		file = fopen(dev_id, "r");

 		if (file == NULL)

@@ -1218,9 +1210,9 @@ static int process_ip_string(FILE *f, char *ip_string, int type)

 static int kvp_set_ip_info(char *if_name, struct hv_kvp_ipaddr_value *new_val)

 {

 	int error = 0;

-	char if_file[128];

+	char if_file[PATH_MAX];

 	FILE *file;

-	char cmd[512];

+	char cmd[PATH_MAX];

 	char *mac_addr;

 	/*