Andrew Griffiths reports that -runas does not set supplementary group
IDs. This means that gid 0 (root) is not dropped when switching to an
unprivileged user.
Add an initgroups(3) call to use the -runas user's /etc/groups
membership to update the supplementary group IDs.
Signed-off-by: Stefan Hajnoczi <stefa...@linux.vnet.ibm.com>
---
Note this needs compile testing on various POSIX host platforms. Tested on
Linux. Should work on BSD and Solaris. initgroups(3) is SVr4/BSD but not in
POSIX.
os-posix.c | 6 ++++++
1 files changed, 6 insertions(+), 0 deletions(-)
diff --git a/os-posix.c b/os-posix.c
index 7dfb278..6f8d488 100644
--- a/os-posix.c
+++ b/os-posix.c
@@ -31,6 +31,7 @@
/*needed for MAP_POPULATE before including qemu-options.h */
#include <sys/mman.h>
#include <pwd.h>
+#include <grp.h>
#include <libgen.h>
/* Needed early for CONFIG_BSD etc. */
@@ -199,6 +200,11 @@ static void change_process_uid(void)
fprintf(stderr, "Failed to setgid(%d)\n", user_pwd->pw_gid);
exit(1);
}
+ if (initgroups(user_pwd->pw_name, user_pwd->pw_gid) < 0) {
+ fprintf(stderr, "Failed to initgroups(\"%s\", %d)\n",
+ user_pwd->pw_name, user_pwd->pw_gid);
+ exit(1);
+ }
if (setuid(user_pwd->pw_uid) < 0) {
fprintf(stderr, "Failed to setuid(%d)\n", user_pwd->pw_uid);
exit(1);
--
1.7.5.4
