| From 51e97a12bef19b7e43199fc153cf9bd5f2140362 Mon Sep 17 00:00:00 2001 |
| From: Dan Rosenberg <drosenberg@vsecurity.com> |
| Date: Fri, 1 Oct 2010 11:51:47 +0000 |
| Subject: sctp: Fix out-of-bounds reading in sctp_asoc_get_hmac() |
| |
| From: Dan Rosenberg <drosenberg@vsecurity.com> |
| |
| commit 51e97a12bef19b7e43199fc153cf9bd5f2140362 upstream. |
| |
| The sctp_asoc_get_hmac() function iterates through a peer's hmac_ids |
| array and attempts to ensure that only a supported hmac entry is |
| returned. The current code fails to do this properly - if the last id |
| in the array is out of range (greater than SCTP_AUTH_HMAC_ID_MAX), the |
| id integer remains set after exiting the loop, and the address of an |
| out-of-bounds entry will be returned and subsequently used in the parent |
| function, causing potentially ugly memory corruption. This patch resets |
| the id integer to 0 on encountering an invalid id so that NULL will be |
| returned after finishing the loop if no valid ids are found. |
| |
| Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com> |
| Acked-by: Vlad Yasevich <vladislav.yasevich@hp.com> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
| |
| --- |
| net/sctp/auth.c | 8 ++++++-- |
| 1 file changed, 6 insertions(+), 2 deletions(-) |
| |
| --- a/net/sctp/auth.c |
| +++ b/net/sctp/auth.c |
| @@ -542,16 +542,20 @@ struct sctp_hmac *sctp_auth_asoc_get_hma |
| id = ntohs(hmacs->hmac_ids[i]); |
| |
| /* Check the id is in the supported range */ |
| - if (id > SCTP_AUTH_HMAC_ID_MAX) |
| + if (id > SCTP_AUTH_HMAC_ID_MAX) { |
| + id = 0; |
| continue; |
| + } |
| |
| /* See is we support the id. Supported IDs have name and |
| * length fields set, so that we can allocated and use |
| * them. We can safely just check for name, for without the |
| * name, we can't allocate the TFM. |
| */ |
| - if (!sctp_hmac_list[id].hmac_name) |
| + if (!sctp_hmac_list[id].hmac_name) { |
| + id = 0; |
| continue; |
| + } |
| |
| break; |
| } |