qemu-bridge-helper: restrict interface name to IFNAMSIZ

The network interface name in Linux is defined to be of size
IFNAMSIZ(=16), including the terminating null('\0') byte.
The same is applied to interface names read from 'bridge.conf'
file to form ACL rules. If user supplied '--br=bridge' name
is not restricted to the same length, it could lead to ACL bypass
issue. Restrict interface name to IFNAMSIZ, including null byte.

Reported-by: Riccardo Schirone <rschiron@redhat.com>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Li Qiang <liq3ea@gmail.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
This commit is contained in:
Prasad J Pandit 2019-07-23 16:17:52 +05:30 committed by Jason Wang
parent f46efa9b08
commit 6f5d867122
1 changed files with 11 additions and 0 deletions

View File

@ -119,6 +119,13 @@ static int parse_acl_file(const char *filename, ACLList *acl_list)
}
*argend = 0;
if (!g_str_equal(cmd, "include") && strlen(arg) >= IFNAMSIZ) {
fprintf(stderr, "name `%s' too long: %zu\n", arg, strlen(arg));
fclose(f);
errno = EINVAL;
return -1;
}
if (strcmp(cmd, "deny") == 0) {
acl_rule = g_malloc(sizeof(*acl_rule));
if (strcmp(arg, "all") == 0) {
@ -269,6 +276,10 @@ int main(int argc, char **argv)
usage();
return EXIT_FAILURE;
}
if (strlen(bridge) >= IFNAMSIZ) {
fprintf(stderr, "name `%s' too long: %zu\n", bridge, strlen(bridge));
return EXIT_FAILURE;
}
/* parse default acl file */
QSIMPLEQ_INIT(&acl_list);