Merge remote-tracking branch 'remotes/kraxel/tags/vnc-20180112-pull-request' into staging

vnc: limit memory usage (CVE-2017-15124)

# gpg: Signature made Fri 12 Jan 2018 12:57:22 GMT
# gpg:                using RSA key 0x4CB6D8EED3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>"
# gpg:                 aka "Gerd Hoffmann <gerd@kraxel.org>"
# gpg:                 aka "Gerd Hoffmann (private) <kraxel@gmail.com>"
# Primary key fingerprint: A032 8CFF B93A 17A7 9901  FE7D 4CB6 D8EE D3E8 7138

* remotes/kraxel/tags/vnc-20180112-pull-request:
  ui: mix misleading comments & return types of VNC I/O helper methods
  ui: add trace events related to VNC client throttling
  ui: place a hard cap on VNC server output buffer size
  ui: fix VNC client throttling when forced update is requested
  ui: fix VNC client throttling when audio capture is active
  ui: refactor code for determining if an update should be sent to the client
  ui: correctly reset framebuffer update state after processing dirty regions
  ui: introduce enum to track VNC client framebuffer update request state
  ui: track how much decoded data we consumed when doing SASL encoding
  ui: avoid pointless VNC updates if framebuffer isn't dirty
  ui: remove redundant indentation in vnc_client_update
  ui: remove unreachable code in vnc_update_client
  ui: remove 'sync' parameter from vnc_update_client
  vnc: fix debug spelling

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 11 insertions, 5 deletions

diff --git a/ui/vnc-auth-sasl.c b/ui/vnc-auth-sasl.c
index 23f28280e7..74a5f513f2 100644
--- a/ui/vnc-auth-sasl.c
+++ b/ui/vnc-auth-sasl.c
@@ -48,9 +48,9 @@ void vnc_sasl_client_cleanup(VncState *vs)
 }
 
 
-long vnc_client_write_sasl(VncState *vs)
+size_t vnc_client_write_sasl(VncState *vs)
 {
-    long ret;
+    size_t ret;
 
     VNC_DEBUG("Write SASL: Pending output %p size %zd offset %zd "
               "Encoded: %p size %d offset %d\n",
@@ -67,6 +67,7 @@ long vnc_client_write_sasl(VncState *vs)
         if (err != SASL_OK)
             return vnc_client_io_error(vs, -1, NULL);
 
+        vs->sasl.encodedRawLength = vs->output.offset;
         vs->sasl.encodedOffset = 0;
     }
 
@@ -78,7 +79,12 @@ long vnc_client_write_sasl(VncState *vs)
 
     vs->sasl.encodedOffset += ret;
     if (vs->sasl.encodedOffset == vs->sasl.encodedLength) {
-        vs->output.offset = 0;
+        if (vs->sasl.encodedRawLength >= vs->force_update_offset) {
+            vs->force_update_offset = 0;
+        } else {
+            vs->force_update_offset -= vs->sasl.encodedRawLength;
+        }
+        vs->output.offset -= vs->sasl.encodedRawLength;
         vs->sasl.encoded = NULL;
         vs->sasl.encodedOffset = vs->sasl.encodedLength = 0;
     }
@@ -100,9 +106,9 @@ long vnc_client_write_sasl(VncState *vs)
 }
 
 
-long vnc_client_read_sasl(VncState *vs)
+size_t vnc_client_read_sasl(VncState *vs)
 {
-    long ret;
+    size_t ret;
     uint8_t encoded[4096];
     const char *decoded;
     unsigned int decodedLen;