[Qemu-devel] [PATCH v2 3/3] net: tap: restrict bridge name to IFNAMSIZ

[P J P <ppandit@redhat.com>]

From: Prasad J Pandit <pjp@fedoraproject.org>

The interface name in Linux interface request struct 'ifreq'
OR in qemu-bridge-helper is defined to be of size IFNAMSIZ(=16),
including the terminating null('\0') byte.

QEMU tap device, while invoking qemu-bridge-helper, supplies bridge
name of 16 characters, restrict it to IFNAMESIZ-1 to accommodate
terminating null('\0') byte.

Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
---
 net/tap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/tap.c b/net/tap.c
index e8aadd8d4b..ca8536624c 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -499,7 +499,7 @@ static int net_bridge_run_helper(const char *helper, const char *bridge,
     if (pid == 0) {
         int open_max = sysconf(_SC_OPEN_MAX), i;
         char fd_buf[6+10];
-        char br_buf[6+IFNAMSIZ] = {0};
+        char br_buf[5+IFNAMSIZ] = {0};
         char helper_cmd[PATH_MAX + sizeof(fd_buf) + sizeof(br_buf) + 15];
 
         for (i = 3; i < open_max; i++) {
-- 
2.21.0