From 74331750f118690ca3c375e52b10272b992320e7 Mon Sep 17 00:00:00 2001

From: Andrea Claudi <aclaudi@redhat.com>

Date: Mon, 29 Apr 2019 20:09:13 +0200

Subject: [PATCH] ip{6, }tunnel: Avoid copying user-supplied interface name

 around

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1465646

Upstream Status: iproute2.git commit 26111ab1dba82

commit 26111ab1dba820421ccaf283ac097a79b95023a2

Author: Phil Sutter <phil@nwl.cc>

Date:   Mon Oct 2 13:46:35 2017 +0200

    ip{6, }tunnel: Avoid copying user-supplied interface name around

    In both files' parse_args() functions as well as in iptunnel's do_prl()

    and do_6rd() functions, a user-supplied 'dev' parameter is uselessly

    copied into a temporary buffer before passing it to ll_name_to_index()

    or copying into a struct ifreq.  Avoid this by just caching the argv

    pointer value until the later lookup/strcpy.

    Signed-off-by: Phil Sutter <phil@nwl.cc>

---

 ip/ip6tunnel.c |  6 +++---

 ip/iptunnel.c  | 22 +++++++++-------------

 2 files changed, 12 insertions(+), 16 deletions(-)

diff --git a/ip/ip6tunnel.c b/ip/ip6tunnel.c

index b4a7def144226..c12d700e74189 100644

--- a/ip/ip6tunnel.c

+++ b/ip/ip6tunnel.c

@@ -136,7 +136,7 @@ static void print_tunnel(struct ip6_tnl_parm2 *p)

 static int parse_args(int argc, char **argv, int cmd, struct ip6_tnl_parm2 *p)

 {

 	int count = 0;

-	char medium[IFNAMSIZ] = {};

+	const char *medium = NULL;

 	while (argc > 0) {

 		if (strcmp(*argv, "mode") == 0) {

@@ -180,7 +180,7 @@ static int parse_args(int argc, char **argv, int cmd, struct ip6_tnl_parm2 *p)

 			memcpy(&p->laddr, &laddr.data, sizeof(p->laddr));

 		} else if (strcmp(*argv, "dev") == 0) {

 			NEXT_ARG();

-			strncpy(medium, *argv, IFNAMSIZ - 1);

+			medium = *argv;

 		} else if (strcmp(*argv, "encaplimit") == 0) {

 			NEXT_ARG();

 			if (strcmp(*argv, "none") == 0) {

@@ -285,7 +285,7 @@ static int parse_args(int argc, char **argv, int cmd, struct ip6_tnl_parm2 *p)

 		count++;

 		argc--; argv++;

 	}

-	if (medium[0]) {

+	if (medium) {

 		p->link = ll_name_to_index(medium);

 		if (p->link == 0) {

 			fprintf(stderr, "Cannot find device \"%s\"\n", medium);

diff --git a/ip/iptunnel.c b/ip/iptunnel.c

index 105d0f5576f1a..0acfd0793d3cd 100644

--- a/ip/iptunnel.c

+++ b/ip/iptunnel.c

@@ -60,7 +60,7 @@ static void set_tunnel_proto(struct ip_tunnel_parm *p, int proto)

 static int parse_args(int argc, char **argv, int cmd, struct ip_tunnel_parm *p)

 {

 	int count = 0;

-	char medium[IFNAMSIZ] = {};

+	const char *medium = NULL;

 	int isatap = 0;

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

@@ -139,7 +139,7 @@ static int parse_args(int argc, char **argv, int cmd, struct ip_tunnel_parm *p)

 				p->iph.saddr = htonl(INADDR_ANY);

 		} else if (strcmp(*argv, "dev") == 0) {

 			NEXT_ARG();

-			strncpy(medium, *argv, IFNAMSIZ - 1);

+			medium = *argv;

 		} else if (strcmp(*argv, "ttl") == 0 ||

 			   strcmp(*argv, "hoplimit") == 0 ||

 			   strcmp(*argv, "hlim") == 0) {

@@ -216,7 +216,7 @@ static int parse_args(int argc, char **argv, int cmd, struct ip_tunnel_parm *p)

 		}

 	}

-	if (medium[0]) {

+	if (medium) {

 		p->link = ll_name_to_index(medium);

 		if (p->link == 0) {

 			fprintf(stderr, "Cannot find device \"%s\"\n", medium);

@@ -465,9 +465,8 @@ static int do_prl(int argc, char **argv)

 {

 	struct ip_tunnel_prl p = {};

 	int count = 0;

-	int devname = 0;

 	int cmd = 0;

-	char medium[IFNAMSIZ] = {};

+	const char *medium = NULL;

 	while (argc > 0) {

 		if (strcmp(*argv, "prl-default") == 0) {

@@ -488,8 +487,7 @@ static int do_prl(int argc, char **argv)

 			count++;

 		} else if (strcmp(*argv, "dev") == 0) {

 			NEXT_ARG();

-			strncpy(medium, *argv, IFNAMSIZ-1);

-			devname++;

+			medium = *argv;

 		} else {

 			fprintf(stderr,

 				"Invalid PRL parameter \"%s\"\n", *argv);

@@ -502,7 +500,7 @@ static int do_prl(int argc, char **argv)

 		}

 		argc--; argv++;

 	}

-	if (devname == 0) {

+	if (!medium) {

 		fprintf(stderr, "Must specify device\n");

 		exit(-1);

 	}

@@ -513,9 +511,8 @@ static int do_prl(int argc, char **argv)

 static int do_6rd(int argc, char **argv)

 {

 	struct ip_tunnel_6rd ip6rd = {};

-	int devname = 0;

 	int cmd = 0;

-	char medium[IFNAMSIZ] = {};

+	const char *medium = NULL;

 	inet_prefix prefix;

 	while (argc > 0) {

@@ -537,8 +534,7 @@ static int do_6rd(int argc, char **argv)

 			cmd = SIOCDEL6RD;

 		} else if (strcmp(*argv, "dev") == 0) {

 			NEXT_ARG();

-			strncpy(medium, *argv, IFNAMSIZ-1);

-			devname++;

+			medium = *argv;

 		} else {

 			fprintf(stderr,

 				"Invalid 6RD parameter \"%s\"\n", *argv);

@@ -546,7 +542,7 @@ static int do_6rd(int argc, char **argv)

 		}

 		argc--; argv++;

 	}

-	if (devname == 0) {

+	if (!medium) {

 		fprintf(stderr, "Must specify device\n");

 		exit(-1);

 	}

-- 

2.20.1