This is a note to let you know that I've just added the patch titled
sctp: validate chunk size in __rcv_asconf_lookup
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:
sctp-validate-chunk-size-in-__rcv_asconf_lookup.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 <stable@xxxxxxxxxxxxxxx> know about it.
>From b6ffe7671b24689c09faa5675dd58f93758a97ae Mon Sep 17 00:00:00 2001
From: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx>
Date: Mon, 28 Jun 2021 16:13:43 -0300
Subject: sctp: validate chunk size in __rcv_asconf_lookup
From: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx>
commit b6ffe7671b24689c09faa5675dd58f93758a97ae upstream.
In one of the fallbacks that SCTP has for identifying an association for an
incoming packet, it looks for AddIp chunk (from ASCONF) and take a peek.
Thing is, at this stage nothing was validating that the chunk actually had
enough content for that, allowing the peek to happen over uninitialized
memory.
Similar check already exists in actual asconf handling in
sctp_verify_asconf().
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/sctp/input.c | 3 +++
1 file changed, 3 insertions(+)
--- a/net/sctp/input.c
+++ b/net/sctp/input.c
@@ -1008,6 +1008,9 @@ static struct sctp_association *__sctp_r
union sctp_addr_param *param;
union sctp_addr paddr;
+ if (ntohs(ch->length) < sizeof(*asconf) + sizeof(struct sctp_paramhdr))
+ return NULL;
+
/* Skip over the ADDIP header and find the Address parameter */
param = (union sctp_addr_param *)(asconf + 1);
Patches currently in stable-queue which might be from marcelo.leitner@xxxxxxxxx are
queue-4.4/sctp-add-param-size-validation-for-sctp_param_set_primary.patch
queue-4.4/sctp-validate-chunk-size-in-__rcv_asconf_lookup.patch
