| Message ID | 1285969907.2814.49.camel@Dan |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
On 10/01/2010 05:51 PM, Dan Rosenberg wrote: > 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> Good catch. Acked-by: Vlad Yasevich <vladislav.yasevich@hp.com> -vlad > > --- linux-2.6.35.5.orig/net/sctp/auth.c 2010-09-20 16:59:09.000000000 -0400 > +++ linux-2.6.35.5/net/sctp/auth.c 2010-10-01 16:48:58.000000000 -0400 > @@ -543,16 +543,20 @@ 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; > } > > -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Vlad Yasevich <vladislav.yasevich@hp.com> Date: Fri, 01 Oct 2010 18:13:34 -0400 > On 10/01/2010 05:51 PM, Dan Rosenberg wrote: >> 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> > > Good catch. > > Acked-by: Vlad Yasevich <vladislav.yasevich@hp.com> Applied. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
--- linux-2.6.35.5.orig/net/sctp/auth.c 2010-09-20 16:59:09.000000000 -0400 +++ linux-2.6.35.5/net/sctp/auth.c 2010-10-01 16:48:58.000000000 -0400 @@ -543,16 +543,20 @@ 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; }
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> -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html