12:56 p.m.
Change the change_process_uid() function so that it takes its input as
parameters instead of relying on static global variables.
Reviewed-by: Eric Blake <eblake(a)redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange(a)redhat.com>
---
os-posix.c | 83 +++++++++++++++++++++++++-----------------------------
1 file changed, 39 insertions(+), 44 deletions(-)
diff --git a/os-posix.c b/os-posix.c
index 7cd662098e..5a127feee2 100644
--- a/os-posix.c
+++ b/os-posix.c
@@ -42,13 +42,9 @@
#include <sys/prctl.h>
#endif
-/*
- * Must set all three of these at once.
- * Legal combinations are unset by name by uid
- */
-static struct passwd *user_pwd; /* NULL non-NULL NULL */
-static uid_t user_uid = (uid_t)-1; /* -1 -1 >=0 */
-static gid_t user_gid = (gid_t)-1; /* -1 -1 >=0 */
+static char *user_name;
+static uid_t user_uid = (uid_t)-1;
+static gid_t user_gid = (gid_t)-1;
static const char *chroot_dir;
static int daemonize;
@@ -100,7 +96,8 @@ void os_set_proc_name(const char *s)
}
-static bool os_parse_runas_uid_gid(const char *optarg)
+static bool os_parse_runas_uid_gid(const char *optarg,
+ uid_t *runas_uid, gid_t *runas_gid)
{
unsigned long lv;
const char *ep;
@@ -120,9 +117,8 @@ static bool os_parse_runas_uid_gid(const char *optarg)
return false;
}
- user_pwd = NULL;
- user_uid = got_uid;
- user_gid = got_gid;
+ *runas_uid = got_uid;
+ *runas_gid = got_gid;
return true;
}
@@ -132,13 +128,18 @@ static bool os_parse_runas_uid_gid(const char *optarg)
*/
int os_parse_cmd_args(int index, const char *optarg)
{
+ struct passwd *user_pwd;
+
switch (index) {
case QEMU_OPTION_runas:
user_pwd = getpwnam(optarg);
if (user_pwd) {
- user_uid = -1;
- user_gid = -1;
- } else if (!os_parse_runas_uid_gid(optarg)) {
+ user_uid = user_pwd->pw_uid;
+ user_gid = user_pwd->pw_gid;
+ user_name = g_strdup(user_pwd->pw_name);
+ } else if (!os_parse_runas_uid_gid(optarg,
+ &user_uid,
+ &user_gid)) {
error_report("User \"%s\" doesn't exist"
" (and is not <uid>:<gid>)",
optarg);
@@ -158,41 +159,33 @@ int os_parse_cmd_args(int index, const char *optarg)
return 0;
}
-static void change_process_uid(void)
+static void change_process_uid(uid_t uid, gid_t gid, const char *name)
{
- assert((user_uid == (uid_t)-1) || user_pwd == NULL);
- assert((user_uid == (uid_t)-1) ==
- (user_gid == (gid_t)-1));
-
- if (user_pwd || user_uid != (uid_t)-1) {
- gid_t intended_gid = user_pwd ? user_pwd->pw_gid : user_gid;
- uid_t intended_uid = user_pwd ? user_pwd->pw_uid : user_uid;
- if (setgid(intended_gid) < 0) {
- error_report("Failed to setgid(%d)", intended_gid);
- exit(1);
- }
- if (user_pwd) {
- if (initgroups(user_pwd->pw_name, user_pwd->pw_gid) < 0) {
- error_report("Failed to initgroups(\"%s\", %d)",
- user_pwd->pw_name, user_pwd->pw_gid);
- exit(1);
- }
- } else {
- if (setgroups(1, &user_gid) < 0) {
- error_report("Failed to setgroups(1, [%d])",
- user_gid);
- exit(1);
- }
- }
- if (setuid(intended_uid) < 0) {
- error_report("Failed to setuid(%d)", intended_uid);
+ if (setgid(gid) < 0) {
+ error_report("Failed to setgid(%d)", gid);
+ exit(1);
+ }
+ if (name) {
+ if (initgroups(name, gid) < 0) {
+ error_report("Failed to initgroups(\"%s\", %d)",
+ name, gid);
exit(1);
}
- if (setuid(0) != -1) {
- error_report("Dropping privileges failed");
+ } else {
+ if (setgroups(1, &gid) < 0) {
+ error_report("Failed to setgroups(1, [%d])",
+ gid);
exit(1);
}
}
+ if (setuid(uid) < 0) {
+ error_report("Failed to setuid(%d)", uid);
+ exit(1);
+ }
+ if (setuid(0) != -1) {
+ error_report("Dropping privileges failed");
+ exit(1);
+ }
}
static void change_root(void)
@@ -275,7 +268,9 @@ void os_setup_post(void)
}
change_root();
- change_process_uid();
+ if (user_uid != -1 && user_gid != -1) {
+ change_process_uid(user_uid, user_gid, user_name);
+ }
if (daemonize) {
uint8_t status = 0;
--
2.34.1