commit 6a9af8184cbc52d52da8985ff4bcec57a72e956c
author Jaeden Amero <jaeden.amero@arm.com> Wed Apr 25 14:25:03 2018 +0100
committer Jaeden Amero <jaeden.amero@arm.com> Wed Apr 25 14:25:03 2018 +0100
tree 148142a1d07f6f1bc9c97122f0e376effdb716d9
parent 4a9236efceb370f7edc52fb4065192a7c42cb212
parent 149f3a4d730fc22324744a6ed657cad55f6c0704

Merge remote-tracking branch 'upstream-public/pr/1595' into mbedtls-2.7-proposed

ChangeLog

diff --git a/ChangeLog b/ChangeLog
index 7248530..ca61c33 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -30,6 +30,8 @@
      the mbedtls_cipher_update() documentation. Contributed by Andy Leiserson.
    * Fix overriding and ignoring return values when parsing and writing to
      a file in pk_sign program. Found by kevlut in #1142.
+   * Fix invalid buffer sizes passed to zlib during record compression and
+     decompression.
 
 Changes
    * Support cmake build where Mbed TLS is a subproject. Fix

library/ssl_tls.c

diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index d386dfa..8db46c3 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -2108,6 +2108,7 @@
 {
     int ret;
     unsigned char *msg_post = ssl->out_msg;
+    ptrdiff_t bytes_written = ssl->out_msg - ssl->out_buf;
     size_t len_pre = ssl->out_msglen;
     unsigned char *msg_pre = ssl->compress_buf;
 
@@ -2127,7 +2128,7 @@
     ssl->transform_out->ctx_deflate.next_in = msg_pre;
     ssl->transform_out->ctx_deflate.avail_in = len_pre;
     ssl->transform_out->ctx_deflate.next_out = msg_post;
-    ssl->transform_out->ctx_deflate.avail_out = MBEDTLS_SSL_BUFFER_LEN;
+    ssl->transform_out->ctx_deflate.avail_out = MBEDTLS_SSL_BUFFER_LEN - bytes_written;
 
     ret = deflate( &ssl->transform_out->ctx_deflate, Z_SYNC_FLUSH );
     if( ret != Z_OK )
@@ -2137,7 +2138,7 @@
     }
 
     ssl->out_msglen = MBEDTLS_SSL_BUFFER_LEN -
-                      ssl->transform_out->ctx_deflate.avail_out;
+                      ssl->transform_out->ctx_deflate.avail_out - bytes_written;
 
     MBEDTLS_SSL_DEBUG_MSG( 3, ( "after compression: msglen = %d, ",
                    ssl->out_msglen ) );
@@ -2154,6 +2155,7 @@
 {
     int ret;
     unsigned char *msg_post = ssl->in_msg;
+    ptrdiff_t header_bytes = ssl->in_msg - ssl->in_buf;
     size_t len_pre = ssl->in_msglen;
     unsigned char *msg_pre = ssl->compress_buf;
 
@@ -2173,7 +2175,8 @@
     ssl->transform_in->ctx_inflate.next_in = msg_pre;
     ssl->transform_in->ctx_inflate.avail_in = len_pre;
     ssl->transform_in->ctx_inflate.next_out = msg_post;
-    ssl->transform_in->ctx_inflate.avail_out = MBEDTLS_SSL_MAX_CONTENT_LEN;
+    ssl->transform_in->ctx_inflate.avail_out = MBEDTLS_SSL_BUFFER_LEN -
+                                               header_bytes;
 
     ret = inflate( &ssl->transform_in->ctx_inflate, Z_SYNC_FLUSH );
     if( ret != Z_OK )
@@ -2182,8 +2185,8 @@
         return( MBEDTLS_ERR_SSL_COMPRESSION_FAILED );
     }
 
-    ssl->in_msglen = MBEDTLS_SSL_MAX_CONTENT_LEN -
-                     ssl->transform_in->ctx_inflate.avail_out;
+    ssl->in_msglen = MBEDTLS_SSL_BUFFER_LEN -
+                     ssl->transform_in->ctx_inflate.avail_out - header_bytes;
 
     MBEDTLS_SSL_DEBUG_MSG( 3, ( "after decompression: msglen = %d, ",
                    ssl->in_msglen ) );