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


Vladimir Olovyannikov
 

Hi Maciej,

Can you please review this patch?
It is sitting there for a while, looks like it slipped through the cracks.

Thank you,
Vladimir

-----Original Message-----
From: Vladimir Olovyannikov <vladimir.olovyannikov@broadcom.com>
Sent: Friday, August 28, 2020 11:17 AM
To: devel@edk2.groups.io
Cc: Vladimir Olovyannikov <vladimir.olovyannikov@broadcom.com>; Maciej
Rabeda <maciej.rabeda@linux.intel.com>; Jiaxin Wu <jiaxin.wu@intel.com>;
Siyuan Fu <siyuan.fu@intel.com>
Subject: [PATCH 1/1] NetworkPkg: Fix possible infinite loop in HTTP msg
body
parser

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@broadcom.com>
Cc: Maciej Rabeda <maciej.rabeda@linux.intel.com>
Cc: Jiaxin Wu <jiaxin.wu@intel.com>
Cc: Siyuan Fu <siyuan.fu@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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