Backported from 5.6.25 by Remi. From 69236ea9793b76b778c6cd64748cfee817521118 Mon Sep 17 00:00:00 2001 From: Stanislav Malyshev Date: Mon, 15 Aug 2016 23:17:26 -0700 Subject: [PATCH] Fix bug #72837 - integer overflow in bzdecompress caused heap corruption --- ext/bz2/bz2.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/ext/bz2/bz2.c b/ext/bz2/bz2.c index 54b59f7..79ec3ec 100644 --- a/ext/bz2/bz2.c +++ b/ext/bz2/bz2.c @@ -573,15 +573,25 @@ static PHP_FUNCTION(bzdecompress) /* compression is better then 2:1, need to allocate more memory */ bzs.avail_out = source_len; size = (bzs.total_out_hi32 * (unsigned int) -1) + bzs.total_out_lo32; + if (size > INT_MAX) { + /* no reason to continue if we're going to drop it anyway */ + break; + } dest = safe_erealloc(dest, 1, bzs.avail_out+1, (size_t) size ); bzs.next_out = dest + size; } if (error == BZ_STREAM_END || error == BZ_OK) { size = (bzs.total_out_hi32 * (unsigned int) -1) + bzs.total_out_lo32; - dest = safe_erealloc(dest, 1, (size_t) size, 1); - dest[size] = '\0'; - RETVAL_STRINGL(dest, (int) size, 0); + if (size > INT_MAX) { + php_error_docref(NULL TSRMLS_CC, E_WARNING, "Decompressed size too big, max is %d", INT_MAX); + efree(dest); + RETVAL_LONG(BZ_MEM_ERROR); + } else { + dest = safe_erealloc(dest, 1, (size_t) size, 1); + dest[size] = '\0'; + RETVAL_STRINGL(dest, (int) size, 0); + } } else { /* real error */ efree(dest); RETVAL_LONG(error);