Patch "509: fix printing uninitialized stack memory when OID is empty" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

509: fix printing uninitialized stack memory when OID is empty

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
509-fix-printing-uninitialized-stack-memory-when-oid-is-empty.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Eric Biggers <[email protected]>
Date: Fri, 8 Dec 2017 15:13:28 +0000
Subject: 509: fix printing uninitialized stack memory when OID is empty

From: Eric Biggers <[email protected]>

[ Upstream commit 8dfd2f22d3bf3ab7714f7495ad5d897b8845e8c1 ]

Callers of sprint_oid() do not check its return value before printing the result. In the case where the OID is zero-length, -EBADMSG was being returned without anything being written to the buffer, resulting in uninitialized stack memory being printed. Fix this by writing "(bad)" to the buffer in the cases where -EBADMSG is returned.

---
 lib/oid_registry.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

@@ -116,7 +116,7 @@ int sprint_oid(const void *data, size_t
 	int count;
 
 	if (v >= end)
-		return -EBADMSG;
+		goto bad;
 
 	n = *v++;
 	ret = count = snprintf(buffer, bufsize, "%u.%u", n / 40, n % 40);

@@ -134,7 +134,7 @@ int sprint_oid(const void *data, size_t
 			num = n & 0x7f;
 			do {
 				if (v >= end)
-					return -EBADMSG;
+					goto bad;
 				n = *v++;
 				num <<= 7;
 				num |= n & 0x7f;

@@ -148,6 +148,10 @@ int sprint_oid(const void *data, size_t
 	}
 
 	return ret;
+
+bad:
+	snprintf(buffer, bufsize, "(bad)");
+	return -EBADMSG;
 }
 EXPORT_SYMBOL_GPL(sprint_oid);
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/509-fix-printing-uninitialized-stack-memory-when-oid-is-empty.patch