fix null pointer dereference introduced in last sigprocmask commit

[musl] / src / signal / sigprocmask.c

diff --git a/src/signal/sigprocmask.c b/src/signal/sigprocmask.c
index e89f876..1bc5baa 100644 (file)
--- a/src/signal/sigprocmask.c
+++ b/src/signal/sigprocmask.c
@@ -1,6 +1,7 @@
 #include <signal.h>
 #include "syscall.h"
 #include "libc.h"
+#include "pthread_impl.h"
 
 int __libc_sigprocmask(int how, const sigset_t *set, sigset_t *old)
 {
@@ -10,11 +11,12 @@ int __libc_sigprocmask(int how, const sigset_t *set, sigset_t *old)
 int __sigprocmask(int how, const sigset_t *set, sigset_t *old)
 {
        sigset_t tmp;
-       /* Quickly mask out bits 32 and 33 (thread control signals) */
-       if (0 && how != SIG_UNBLOCK && (set->__bits[4/sizeof *set->__bits] & 3UL<<(32&8*sizeof *set->__bits-1))) {
+       /* Disallow blocking thread control signals */
+       if (set && how != SIG_UNBLOCK) {
                tmp = *set;
                set = &tmp;
-               tmp.__bits[4/sizeof *set->__bits] &= ~(3UL<<(32&8*sizeof *set->__bits-1));
+               sigdelset(&tmp, SIGCANCEL);
+               sigdelset(&tmp, SIGSYSCALL);
        }
        return __libc_sigprocmask(how, set, old);
 }