[edk2-devel] [edk2-libc Patch] StdLib/LibC/StdLib: Handle possible math overflow in malloc()

[Michael D Kinney]

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1510

Check for addition overflow in malloc() when computing NodeSize
and return error if overflow is detected.

Cc: Rebecca Cran <rebecca at nuviainc.com>
Cc: Yitzhak Briskman <yitzhak.briskman at intel.com>
Cc: Jian J Wang <jian.j.wang at intel.com>
Cc: Yonghong Zhu <yonghong.zhu at intel.com>
Signed-off-by: Michael D Kinney <michael.d.kinney at intel.com>
---
 StdLib/LibC/StdLib/Malloc.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/StdLib/LibC/StdLib/Malloc.c b/StdLib/LibC/StdLib/Malloc.c
index c131b9e..7bf8827 100644
--- a/StdLib/LibC/StdLib/Malloc.c
+++ b/StdLib/LibC/StdLib/Malloc.c
@@ -94,6 +94,12 @@ malloc(size_t Size)
     return NULL;
   }
 
+  if ((Size + sizeof(CPOOL_HEAD)) < Size) {
+    RetVal  = NULL;
+    errno   = ENOMEM;
+    DEBUG((DEBUG_ERROR, "\nERROR malloc: Size overflow\n"));
+  }
+
   NodeSize = (UINTN)(Size + sizeof(CPOOL_HEAD));
 
   DEBUG((DEBUG_POOL, "malloc(%d): NodeSz: %d", Size, NodeSize));
-- 
2.32.0.windows.1



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