[edk2-devel] [PATCH 1/1] NetworkPkg: Fix possible infinite loop in HTTP msg body parser

[Vladimir Olovyannikov via groups.io]

When an HTTP server sends a non-chunked body data with no
Content-Length header, the HttpParserMessageBody in DxeHttpLib
gets confused and never sets the Char pointer beyond the body start.
This causes "for" loop to never break because the condition of
"Char >= Body + BodyLength" is never satisfied.
Use BodyLength as the ContentLength for the parser when
ContentLength is absent in HTTP response headers.
BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2941

Signed-off-by: Vladimir Olovyannikov <vladimir.olovyannikov at broadcom.com>
Cc: Maciej Rabeda <maciej.rabeda at linux.intel.com>
Cc: Jiaxin Wu <jiaxin.wu at intel.com>
Cc: Siyuan Fu <siyuan.fu at intel.com>
---
 NetworkPkg/Library/DxeHttpLib/DxeHttpLib.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/NetworkPkg/Library/DxeHttpLib/DxeHttpLib.c b/NetworkPkg/Library/DxeHttpLib/DxeHttpLib.c
index 180d9321025a..e550c9962dc1 100644
--- a/NetworkPkg/Library/DxeHttpLib/DxeHttpLib.c
+++ b/NetworkPkg/Library/DxeHttpLib/DxeHttpLib.c
@@ -1122,6 +1122,7 @@ HttpParseMessageBody (
   CHAR8                 *Char;
   UINTN                 RemainderLengthInThis;
   UINTN                 LengthForCallback;
+  UINTN                 PortionLength;
   EFI_STATUS            Status;
   HTTP_BODY_PARSER      *Parser;
 
@@ -1173,19 +1174,31 @@ HttpParseMessageBody (
       //
       // Identity transfer-coding, just notify user to save the body data.
       //
+      PortionLength = MIN (
+                        BodyLength,
+                        Parser->ContentLength - Parser->ParsedBodyLength
+                        );
+      if (!PortionLength) {
+        //
+        // Got BodyLength, but no ContentLength. Use BodyLength.
+        //
+        PortionLength = BodyLength;
+        Parser->ContentLength = PortionLength;
+      }
+
       if (Parser->Callback != NULL) {
         Status = Parser->Callback (
                            BodyParseEventOnData,
                            Char,
-                           MIN (BodyLength, Parser->ContentLength - Parser->ParsedBodyLength),
+                           PortionLength,
                            Parser->Context
                            );
         if (EFI_ERROR (Status)) {
           return Status;
         }
       }
-      Char += MIN (BodyLength, Parser->ContentLength - Parser->ParsedBodyLength);
-      Parser->ParsedBodyLength += MIN (BodyLength, Parser->ContentLength - Parser->ParsedBodyLength);
+      Char += PortionLength;
+      Parser->ParsedBodyLength += PortionLength;
       if (Parser->ParsedBodyLength == Parser->ContentLength) {
         Parser->State = BodyParserComplete;
         if (Parser->Callback != NULL) {
-- 
2.26.2.266.ge870325ee8


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