Merge pull request #1043 from Hummer12007/caps

Keep CAP_SYS_PTRACE with suid binary
This commit is contained in:
Drew DeVault 2017-01-12 11:39:14 -05:00 committed by GitHub
commit 307e8afde2

View file

@ -10,6 +10,9 @@
#include <unistd.h>
#include <getopt.h>
#include <sys/capability.h>
#ifdef __linux__
#include <sys/prctl.h>
#endif
#include "sway/extensions.h"
#include "sway/layout.h"
#include "sway/config.h"
@ -289,6 +292,18 @@ int main(int argc, char **argv) {
return 0;
}
#ifdef __linux__
bool suid = false;
if (getuid() != geteuid() || getgid() != getegid()) {
// Retain capabilities after setuid()
if (prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0)) {
sway_log(L_ERROR, "Cannot keep caps after setuid()");
exit(EXIT_FAILURE);
}
suid = true;
}
#endif
// we need to setup logging before wlc_init in case it fails.
if (debug) {
init_log(L_DEBUG);
@ -311,6 +326,20 @@ int main(int argc, char **argv) {
}
register_extensions();
#ifdef __linux__
if (suid) {
// Drop every cap except CAP_SYS_PTRACE
cap_t caps = cap_init();
cap_value_t keep = CAP_SYS_PTRACE;
sway_log(L_INFO, "Dropping extra capabilities");
if (cap_set_flag(caps, CAP_PERMITTED, 1, &keep, CAP_SET) ||
cap_set_flag(caps, CAP_EFFECTIVE, 1, &keep, CAP_SET) ||
cap_set_proc(caps)) {
sway_log(L_ERROR, "Failed to drop extra capabilities");
exit(EXIT_FAILURE);
}
}
#endif
// handle SIGTERM signals
signal(SIGTERM, sig_handler);