[34-longterm 021/196] irda: validate peer name and attribute lengths

From: Paul Gortmaker
Date: Mon Mar 12 2012 - 21:05:41 EST


From: Dan Rosenberg <drosenberg@xxxxxxxxxxxxx>

-------------------
This is a commit scheduled for the next v2.6.34 longterm release.
If you see a problem with using this for longterm, please comment.
-------------------

commit d370af0ef7951188daeb15bae75db7ba57c67846 upstream.

Length fields provided by a peer for names and attributes may be longer
than the destination array sizes. Validate lengths to prevent stack
buffer overflows.

Signed-off-by: Dan Rosenberg <drosenberg@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx>
---
net/irda/iriap.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/net/irda/iriap.c b/net/irda/iriap.c
index b6fd6d1..26272fe 100644
--- a/net/irda/iriap.c
+++ b/net/irda/iriap.c
@@ -656,10 +656,16 @@ static void iriap_getvaluebyclass_indication(struct iriap_cb *self,
n = 1;

name_len = fp[n++];
+
+ IRDA_ASSERT(name_len < IAS_MAX_CLASSNAME + 1, return;);
+
memcpy(name, fp+n, name_len); n+=name_len;
name[name_len] = '\0';

attr_len = fp[n++];
+
+ IRDA_ASSERT(attr_len < IAS_MAX_ATTRIBNAME + 1, return;);
+
memcpy(attr, fp+n, attr_len); n+=attr_len;
attr[attr_len] = '\0';

--
1.7.9.3

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