summaryrefslogtreecommitdiff
path: root/src
diff options
context:
space:
mode:
Diffstat (limited to 'src')
-rw-r--r--src/unistd/setxid.c38
1 files changed, 15 insertions, 23 deletions
diff --git a/src/unistd/setxid.c b/src/unistd/setxid.c
index 2f651a11..9e37ddc4 100644
--- a/src/unistd/setxid.c
+++ b/src/unistd/setxid.c
@@ -1,43 +1,35 @@
#include <unistd.h>
#include <errno.h>
-#include <sys/resource.h>
#include "syscall.h"
#include "libc.h"
+#include "pthread_impl.h"
struct ctx {
int id, eid, sid;
- int nr, rlim, err;
+ int nr, err;
};
-/* We jump through hoops to eliminate the possibility of partial failures. */
-
-int __setrlimit(int, const struct rlimit *);
-
static void do_setxid(void *p)
{
struct ctx *c = p;
- if (c->err) return;
- if (c->rlim && c->id >= 0 && c->id != getuid()) {
- struct rlimit inf = { RLIM_INFINITY, RLIM_INFINITY }, old;
- getrlimit(RLIMIT_NPROC, &old);
- if ((c->err = -__setrlimit(RLIMIT_NPROC, &inf)) && libc.threads_minus_1)
- return;
- c->err = -__syscall(c->nr, c->id, c->eid, c->sid);
- __setrlimit(RLIMIT_NPROC, &old);
- return;
+ if (c->err>0) return;
+ int ret = -__syscall(c->nr, c->id, c->eid, c->sid);
+ if (ret && !c->err) {
+ /* If one thread fails to set ids after another has already
+ * succeeded, forcibly killing the process is the only safe
+ * thing to do. State is inconsistent and dangerous. Use
+ * SIGKILL because it is uncatchable. */
+ __block_all_sigs(0);
+ __syscall(SYS_kill, __syscall(SYS_getpid), SIGKILL);
}
- c->err = -__syscall(c->nr, c->id, c->eid, c->sid);
+ c->err = ret;
}
int __setxid(int nr, int id, int eid, int sid)
{
- struct ctx c = { .nr = nr, .id = id, .eid = eid, .sid = sid };
- switch (nr) {
- case SYS_setuid:
- case SYS_setreuid:
- case SYS_setresuid:
- c.rlim = 1;
- }
+ /* err is initially nonzero so that failure of the first thread does not
+ * trigger the safety kill above. */
+ struct ctx c = { .nr = nr, .id = id, .eid = eid, .sid = sid, .err = -1 };
__synccall(do_setxid, &c);
if (c.err) {
errno = c.err;