This is a note to let you know that I've just added the patch titled
net: sctp: fix memory leak in auth key management
to the 3.17-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:
net-sctp-fix-memory-leak-in-auth-key-management.patch
and it can be found in the queue-3.17 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Tue Nov 18 09:07:25 PST 2014
From: Daniel Borkmann <dborkman@xxxxxxxxxx>
Date: Mon, 10 Nov 2014 18:00:09 +0100
Subject: net: sctp: fix memory leak in auth key management
From: Daniel Borkmann <dborkman@xxxxxxxxxx>
[ Upstream commit 4184b2a79a7612a9272ce20d639934584a1f3786 ]
A very minimal and simple user space application allocating an SCTP
socket, setting SCTP_AUTH_KEY setsockopt(2) on it and then closing
the socket again will leak the memory containing the authentication
key from user space:
unreferenced object 0xffff8800837047c0 (size 16):
comm "a.out", pid 2789, jiffies 4296954322 (age 192.258s)
hex dump (first 16 bytes):
01 00 00 00 04 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff816d7e8e>] kmemleak_alloc+0x4e/0xb0
[<ffffffff811c88d8>] __kmalloc+0xe8/0x270
[<ffffffffa0870c23>] sctp_auth_create_key+0x23/0x50 [sctp]
[<ffffffffa08718b1>] sctp_auth_set_key+0xa1/0x140 [sctp]
[<ffffffffa086b383>] sctp_setsockopt+0xd03/0x1180 [sctp]
[<ffffffff815bfd94>] sock_common_setsockopt+0x14/0x20
[<ffffffff815beb61>] SyS_setsockopt+0x71/0xd0
[<ffffffff816e58a9>] system_call_fastpath+0x12/0x17
[<ffffffffffffffff>] 0xffffffffffffffff
This is bad because of two things, we can bring down a machine from
user space when auth_enable=1, but also we would leave security sensitive
keying material in memory without clearing it after use. The issue is
that sctp_auth_create_key() already sets the refcount to 1, but after
allocation sctp_auth_set_key() does an additional refcount on it, and
thus leaving it around when we free the socket.
Fixes: 65b07e5d0d0 ("[SCTP]: API updates to suport SCTP-AUTH extensions.")
Signed-off-by: Daniel Borkmann <dborkman@xxxxxxxxxx>
Cc: Vlad Yasevich <vyasevich@xxxxxxxxx>
Acked-by: Neil Horman <nhorman@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/sctp/auth.c | 2 --
1 file changed, 2 deletions(-)
--- a/net/sctp/auth.c
+++ b/net/sctp/auth.c
@@ -862,8 +862,6 @@ int sctp_auth_set_key(struct sctp_endpoi
list_add(&cur_key->key_list, sh_keys);
cur_key->key = key;
- sctp_auth_key_hold(key);
-
return 0;
nomem:
if (!replace)
Patches currently in stable-queue which might be from dborkman@xxxxxxxxxx are
queue-3.17/net-sctp-fix-memory-leak-in-auth-key-management.patch
queue-3.17/net-sctp-fix-null-pointer-dereference-in-af-from_addr_param-on-malformed-packet.patch
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