[msan] Check sigset_t and sigaction arguments.

Summary:
Check sigset_t arguments in ppoll, sig*wait*, sigprocmask
interceptors, and the entire "struct sigaction" in sigaction. This
can be done because sigemptyset/sigfullset are intercepted and
signal masks should be correctly marked as initialized.

Reviewers: vitalybuka

Subscribers: kubamracek, llvm-commits

Differential Revision: https://reviews.llvm.org/D37367

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@312576 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 10 insertions, 0 deletions

diff --git a/lib/msan/msan_interceptors.cc b/lib/msan/msan_interceptors.cc
index 08eb261aa..916e25557 100644
--- a/lib/msan/msan_interceptors.cc
+++ b/lib/msan/msan_interceptors.cc
@@ -983,11 +983,21 @@ static void SignalAction(int signo, void *si, void *uc) {
   cb(signo, si, uc);
 }
 
+static void read_sigaction(const __sanitizer_sigaction *act) {
+  CHECK_UNPOISONED(&act->sa_flags, sizeof(act->sa_flags));
+  if (act->sa_flags & __sanitizer::sa_siginfo)
+    CHECK_UNPOISONED(&act->sigaction, sizeof(act->sigaction));
+  else
+    CHECK_UNPOISONED(&act->handler, sizeof(act->handler));
+  CHECK_UNPOISONED(&act->sa_mask, sizeof(act->sa_mask));
+}
+
 INTERCEPTOR(int, sigaction, int signo, const __sanitizer_sigaction *act,
             __sanitizer_sigaction *oldact) {
   ENSURE_MSAN_INITED();
   // FIXME: check that *act is unpoisoned.
   // That requires intercepting all of sigemptyset, sigfillset, etc.
+  if (act) read_sigaction(act);
   int res;
   if (flags()->wrap_signals) {
     SpinMutexLock lock(&sigactions_mu);