From 1e7478461bb4e8842f1ca8e5ffb5a441041b0753 Mon Sep 17 00:00:00 2001
From: =?utf8?q?Pali=20Roh=C3=A1r?= <pali@kernel.org>
Date: Tue, 3 Aug 2021 16:28:38 +0200
Subject: [PATCH] xyz-modem: Fix crash after cancelling transfer
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Variable xyz.len is set to -1 on error. At the end xyzModem_stream_read()
function calls memcpy() with length from variable xyz.len. If this variable
is set to -1 then value passed to memcpy is casted to unsigned value, which
means to copy whole address space. Which then cause U-Boot crash. E.g. on
arm64 it cause CPU crash: "Synchronous Abort" handler, esr 0x96000006
Fix this issue by checking that value stored in xyz.len is valid prior
trying to use it.
Signed-off-by: Pali Rohár <pali@kernel.org>
Acked-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
---
common/xyzModem.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/common/xyzModem.c b/common/xyzModem.c
index fc3459ebba..b1b72aae0b 100644
--- a/common/xyzModem.c
+++ b/common/xyzModem.c
@@ -494,7 +494,7 @@ xyzModem_stream_read (char *buf, int size, int *err)
total = 0;
stat = xyzModem_cancel;
/* Try and get 'size' bytes into the buffer */
- while (!xyz.at_eof && (size > 0))
+ while (!xyz.at_eof && xyz.len >= 0 && (size > 0))
{
if (xyz.len == 0)
{
@@ -587,7 +587,7 @@ xyzModem_stream_read (char *buf, int size, int *err)
}
}
/* Don't "read" data from the EOF protocol package */
- if (!xyz.at_eof)
+ if (!xyz.at_eof && xyz.len > 0)
{
len = xyz.len;
if (size < len)
--
2.39.5