em_inflate.c

commit e536ec708f0d39b27024c80d40e420c29906a39a
parent b6ec4ed7517833f60f6515fe3b708e250c33d175
Author: zhangxinlong633 <15205157627@163.com>
Date:   Tue, 11 Aug 2020 11:17:16 +0800

fix buffer overflow

fix buffer overflow
Diffstat:
M
lib/em_inflate.c
 | 
7
++++++-

1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/lib/em_inflate.c b/lib/em_inflate.c
@@ -598,7 +598,12 @@ static size_t em_inflate_decompress_block(em_lsb_bitreader_t *pBitReader, int nD
    for (i = 0; i < NLITERALSYMS; i++) {
       unsigned int n = nLiteralsRevSymbolTable[i];
       if (n >= NMATCHLENSYMSTART && n < NLITERALSYMS) {
-         nLiteralsRevSymbolTable[i] = em_inflate_matchlen_code[n - NMATCHLENSYMSTART];
+        int index = n - NMATCHLENSYMSTART;
+        if (index >= 0 && index < NMATCHLENSYMS) {
+            nLiteralsRevSymbolTable[i] = em_inflate_matchlen_code[index];
+        } else {
+            return -1;
+        }      
       }
    }