From patchwork Thu Jul 7 22:12:19 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [lucid/fsl-imx51, maverick, maverick/ti-omap4, natty/ti-omap4, CVE, 1/1] dccp: handle invalid feature options length Date: Thu, 07 Jul 2011 12:12:19 -0000 From: Andy Whitcroft X-Patchwork-Id: 103736 Message-Id: <1310076739-23810-2-git-send-email-apw@canonical.com> To: kernel-team@lists.ubuntu.com From: Dan Rosenberg A length of zero (after subtracting two for the type and len fields) for the DCCPO_{CHANGE,CONFIRM}_{L,R} options will cause an underflow due to the subtraction. The subsequent code may read past the end of the options value buffer when parsing. I'm unsure of what the consequences of this might be, but it's probably not good. Signed-off-by: Dan Rosenberg Cc: stable@kernel.org Acked-by: Gerrit Renker Signed-off-by: David S. Miller (cherry picked from commit a294865978b701e4d0d90135672749531b9a900d) CVE-2011-1770 BugLink: http://bugs.launchpad.net/bugs/806375 Signed-off-by: Andy Whitcroft --- net/dccp/options.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/net/dccp/options.c b/net/dccp/options.c index 1b08cae..b4a853e 100644 --- a/net/dccp/options.c +++ b/net/dccp/options.c @@ -131,6 +131,8 @@ int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq, case DCCPO_CHANGE_L ... DCCPO_CONFIRM_R: if (pkt_type == DCCP_PKT_DATA) /* RFC 4340, 6 */ break; + if (len == 0) + goto out_invalid_option; rc = dccp_feat_parse_options(sk, dreq, mandatory, opt, *value, value + 1, len - 1); if (rc)