From 070e7b81c0d673cfafba5a41914259503d459adf Mon Sep 17 00:00:00 2001 From: Jean-Michel Trivi Date: Mon, 30 Oct 2017 15:20:44 -0700 Subject: [PATCH] DO NOT MERGE Prevent out of bound memory access in GetInvInt In GetInvInt(int) function, malicious content can access memory outside of the invCount array. Always bound access to valid indices. Test: see bug for malicious content, decoded with "stagefright -s -a" Bug: 65025048 Change-Id: Iff889601828f95b82d9291075f3909922ef533ef --- libFDK/include/fixpoint_math.h | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/libFDK/include/fixpoint_math.h b/libFDK/include/fixpoint_math.h index df141d3..26c001f 100644 --- a/libFDK/include/fixpoint_math.h +++ b/libFDK/include/fixpoint_math.h @@ -450,15 +450,19 @@ inline FIXP_DBL fAddSaturate(const FIXP_DBL a, const FIXP_DBL b) /** * \brief Calculate the value of 1/i where i is a integer value. It supports - * input values from 1 upto 50. + * input values from 0 upto 49. * \param intValue Integer input value. * \param FIXP_DBL representation of 1/intValue */ inline FIXP_DBL GetInvInt(int intValue) { - FDK_ASSERT((intValue > 0) && (intValue < 50)); - FDK_ASSERT(intValue<50); - return invCount[intValue]; + FDK_ASSERT((intValue >= 0) && (intValue < 50)); + if (intValue < 0) + return invCount[0]; + else if (intValue > 49) + return invCount[49]; + else + return invCount[intValue]; }