File opensc-tcos-bound-check.patch of Package opensc

From 5df913b7f57ad89b9832555d24c08d23a534311e Mon Sep 17 00:00:00 2001
From: Jakub Jelen <jjelen@redhat.com>
Date: Tue, 8 Dec 2020 14:37:39 +0100
Subject: [PATCH] tcos: Check bounds in insert_pin()

Thanks oss-fuzz

https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=28383
---
 src/libopensc/pkcs15-tcos.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Index: opensc-0.19.0/src/libopensc/pkcs15-tcos.c
===================================================================
--- opensc-0.19.0.orig/src/libopensc/pkcs15-tcos.c
+++ opensc-0.19.0/src/libopensc/pkcs15-tcos.c
@@ -233,10 +233,10 @@ static int insert_pin(
 			"Searching for PIN-Ref %02X\n", pin_reference);
 		while((r=sc_read_record(card, ++rec_no, buf, sizeof(buf), SC_RECORD_BY_REC_NR))>0){
 			int found=0, fbz=-1;
-			if(buf[0]!=0xA0) continue;
-			for(i=2;i<buf[1]+2;i+=2+buf[i+1]){
+			if(r < 2 || buf[0]!=0xA0) continue;
+			for(i=2;i<buf[1]+2 && (i + 2) < r;i+=2+buf[i+1]){
 				if(buf[i]==0x83 && buf[i+1]==1 && buf[i+2]==pin_reference) ++found;
-				if(buf[i]==0x90) fbz=buf[i+1+buf[i+1]];
+				if(buf[i]==0x90 && (i + 1 + buf[i + 1]) < r) fbz=buf[i+1+buf[i+1]];
 			}
 			if(found) pin_info.tries_left=fbz;
 			if(found) break;