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* [edk2-platforms][PATCH 1/1] Platform/RPi: Prevent buffer over-read when the command line is empty
@ 2019-11-04 16:06 Pete Batard
  2019-11-04 16:27 ` Philippe Mathieu-Daudé
  2019-11-07 16:21 ` Leif Lindholm
  0 siblings, 2 replies; 7+ messages in thread
From: Pete Batard @ 2019-11-04 16:06 UTC (permalink / raw)
  To: devel; +Cc: ard.biesheuvel, leif.lindholm, philmd

From: Andrei Warkentin <andrey.warkentin@gmail.com>

It is possible for the command line to be empty
(Cmd->TagHead.TagValueSize = 0), in which case the code should not
attempt to read the value at CommandLine[-1].

Signed-off-by: Pete Batard <pete@akeo.ie>
---
 Platform/RaspberryPi/Drivers/RpiFirmwareDxe/RpiFirmwareDxe.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Platform/RaspberryPi/Drivers/RpiFirmwareDxe/RpiFirmwareDxe.c b/Platform/RaspberryPi/Drivers/RpiFirmwareDxe/RpiFirmwareDxe.c
index 5a9d4c3f1787..9b4aa068857c 100644
--- a/Platform/RaspberryPi/Drivers/RpiFirmwareDxe/RpiFirmwareDxe.c
+++ b/Platform/RaspberryPi/Drivers/RpiFirmwareDxe/RpiFirmwareDxe.c
@@ -927,7 +927,8 @@ RpiFirmwareGetCommmandLine (
 
   CopyMem (CommandLine, Cmd->CommandLine, Cmd->TagHead.TagValueSize);
 
-  if (CommandLine[Cmd->TagHead.TagValueSize - 1] != '\0') {
+  if (Cmd->TagHead.TagValueSize == 0 ||
+      CommandLine[Cmd->TagHead.TagValueSize - 1] != '\0') {
     //
     // Add a NUL terminator if required.
     //
-- 
2.21.0.windows.1


^ permalink raw reply related	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2019-11-07 18:09 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2019-11-04 16:06 [edk2-platforms][PATCH 1/1] Platform/RPi: Prevent buffer over-read when the command line is empty Pete Batard
2019-11-04 16:27 ` Philippe Mathieu-Daudé
2019-11-07 16:21 ` Leif Lindholm
2019-11-07 17:05   ` Pete Batard
2019-11-07 17:27     ` Leif Lindholm
2019-11-07 17:35       ` Pete Batard
2019-11-07 18:09         ` Leif Lindholm

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