[compiler-rt] ae0ed3d - [lsan] Fix free(NULL) interception during initialization (#106912)

[via llvm-commits]

Author: tmiasko
Date: 2024-09-11T15:37:02-07:00
New Revision: ae0ed3d58600da9ec266bf86d0084775f561ba3a

URL: https://github.com/llvm/llvm-project/commit/ae0ed3d58600da9ec266bf86d0084775f561ba3a
DIFF: https://github.com/llvm/llvm-project/commit/ae0ed3d58600da9ec266bf86d0084775f561ba3a.diff

LOG: [lsan] Fix free(NULL) interception during initialization (#106912)

Previously an attempt to free a null pointer during initialization would
fail on ENSURE_LSAN_INITED assertion (since a null pointer is not owned
by DlsymAlloc).

Added: 
    

Modified: 
    compiler-rt/lib/lsan/lsan_interceptors.cpp
    compiler-rt/test/sanitizer_common/TestCases/dlsym_alloc.c

Removed: 
    


################################################################################
diff  --git a/compiler-rt/lib/lsan/lsan_interceptors.cpp b/compiler-rt/lib/lsan/lsan_interceptors.cpp
index b569c337e97641..efbf2fdfb0ab3f 100644
--- a/compiler-rt/lib/lsan/lsan_interceptors.cpp
+++ b/compiler-rt/lib/lsan/lsan_interceptors.cpp
@@ -77,6 +77,8 @@ INTERCEPTOR(void*, malloc, uptr size) {
 }
 
 INTERCEPTOR(void, free, void *p) {
+  if (UNLIKELY(!p))
+    return;
   if (DlsymAlloc::PointerIsMine(p))
     return DlsymAlloc::Free(p);
   ENSURE_LSAN_INITED;

diff  --git a/compiler-rt/test/sanitizer_common/TestCases/dlsym_alloc.c b/compiler-rt/test/sanitizer_common/TestCases/dlsym_alloc.c
index 3905ac40ae2dc7..0228c3bc50dbd9 100644
--- a/compiler-rt/test/sanitizer_common/TestCases/dlsym_alloc.c
+++ b/compiler-rt/test/sanitizer_common/TestCases/dlsym_alloc.c
@@ -3,9 +3,6 @@
 // FIXME: TSAN does not use DlsymAlloc.
 // UNSUPPORTED: tsan
 
-// FIXME: https://github.com/llvm/llvm-project/pull/106912
-// XFAIL: lsan
-
 #include <stdlib.h>
 
 const char *test() __attribute__((disable_sanitizer_instrumentation)) {