passt: Drop all capabilities that we might have, except for CAP_NET_BIND_SERVICE

While it's not recommended to give passt any capability, drop all the
ones we might have got by mistake, except for the only sensible one,
CAP_NET_BIND_SERVICE.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
This commit is contained in:
Stefano Brivio 2021-10-14 02:47:03 +02:00
parent 32d07f5e59
commit 9f1724ad1e

18
passt.c
View file

@ -55,6 +55,7 @@
#include <sys/prctl.h>
#include <linux/filter.h>
#include <stddef.h>
#include <linux/capability.h>
#include "seccomp.h"
#include "util.h"
@ -185,6 +186,21 @@ static void seccomp(struct ctx *c)
}
}
/**
* drop_caps() - Drop capabilities we might have except for CAP_NET_BIND_SERVICE
*/
static void drop_caps(void)
{
int i;
for (i = 0; i < 64; i++) {
if (i == CAP_NET_BIND_SERVICE)
continue;
prctl(PR_CAPBSET_DROP, i, 0, 0, 0);
}
}
/**
* main() - Entry point and main loop
* @argc: Argument count
@ -207,6 +223,8 @@ int main(int argc, char **argv)
char *log_name;
int nfds, i;
drop_caps();
if (strstr(argv[0], "pasta") || strstr(argv[0], "passt4netns")) {
struct sigaction sa;