Repository : ssh://git@open-mesh.org/alfred
On branch : master
commit 9f426172712daa5f502743070d4cca3309366dd4 Author: Sven Eckelmann sven@narfation.org Date: Sat May 24 13:44:07 2014 +0200
alfred: Force null termination of string after strncpy
strncpy doesn't terminate the string with a '\0' character when the length of the destination memory location was shorter than the source string. Accessing it again with string related functions isn't safe after such a semi-failed copy and the caller has to handle it. The easiest way is to always set the last character in the destination buffer to '\0' after the strncpy was called.
Signed-off-by: Sven Eckelmann sven@narfation.org Signed-off-by: Simon Wunderlich sw@simonwunderlich.de
9f426172712daa5f502743070d4cca3309366dd4 debugfs.c | 1 + netsock.c | 1 + server.c | 1 + vis/vis.c | 1 + 4 files changed, 4 insertions(+)
diff --git a/debugfs.c b/debugfs.c index 1e9418d..adada7c 100644 --- a/debugfs.c +++ b/debugfs.c @@ -154,6 +154,7 @@ char *debugfs_mount(const char *mountpoint)
/* save the mountpoint */ strncpy(debugfs_mountpoint, mountpoint, sizeof(debugfs_mountpoint)); + debugfs_mountpoint[sizeof(debugfs_mountpoint) - 1] = '\0'; debugfs_found = 1;
return debugfs_mountpoint; diff --git a/netsock.c b/netsock.c index 08d2959..8712c11 100644 --- a/netsock.c +++ b/netsock.c @@ -59,6 +59,7 @@ int netsock_open(struct globals *globals)
memset(&ifr, 0, sizeof(ifr)); strncpy(ifr.ifr_name, globals->interface, IFNAMSIZ); + ifr.ifr_name[IFNAMSIZ - 1] = '\0'; if (ioctl(sock, SIOCGIFINDEX, &ifr) == -1) { fprintf(stderr, "can't get interface: %s\n", strerror(errno)); goto err; diff --git a/server.c b/server.c index fdd97d4..e4465dc 100644 --- a/server.c +++ b/server.c @@ -242,6 +242,7 @@ static void check_if_socket(struct globals *globals)
memset(&ifr, 0, sizeof(ifr)); strncpy(ifr.ifr_name, globals->interface, IFNAMSIZ); + ifr.ifr_name[IFNAMSIZ - 1] = '\0'; if (ioctl(sock, SIOCGIFINDEX, &ifr) == -1) { fprintf(stderr, "can't get interface: %s, closing netsock\n", strerror(errno)); diff --git a/vis/vis.c b/vis/vis.c index b51fede..9031b27 100644 --- a/vis/vis.c +++ b/vis/vis.c @@ -102,6 +102,7 @@ static int get_if_mac(char *ifname, uint8_t *mac) int sock, ret;
strncpy(ifr.ifr_name, ifname, IFNAMSIZ); + ifr.ifr_name[IFNAMSIZ - 1] = '\0';
if ((sock = socket(AF_INET, SOCK_STREAM, 0)) < 0) { fprintf(stderr, "can't get interface: %s\n", strerror(errno));