From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Greg Kroah-Hartman , Tyler Hicks , Seth Arnold , Stefan Bader Subject: [PATCH 4.4 39/60] irda: Only insert new objects into the global database via setsockopt Date: Thu, 13 Sep 2018 15:30:46 +0200 Message-Id: <20180913131747.276535834@linuxfoundation.org> In-Reply-To: <20180913131745.261413581@linuxfoundation.org> References: <20180913131745.261413581@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tyler Hicks The irda_setsockopt() function conditionally allocates memory for a new self->ias_object or, in some cases, reuses the existing self->ias_object. Existing objects were incorrectly reinserted into the LM_IAS database which corrupted the doubly linked list used for the hashbin implementation of the LM_IAS database. When combined with a memory leak in irda_bind(), this issue could be leveraged to create a use-after-free vulnerability in the hashbin list. This patch fixes the issue by only inserting newly allocated objects into the database. CVE-2018-6555 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Tyler Hicks Reviewed-by: Seth Arnold Reviewed-by: Stefan Bader Signed-off-by: Greg Kroah-Hartman --- net/irda/af_irda.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/net/irda/af_irda.c +++ b/net/irda/af_irda.c @@ -2027,7 +2027,11 @@ static int irda_setsockopt(struct socket err = -EINVAL; goto out; } - irias_insert_object(ias_obj); + + /* Only insert newly allocated objects */ + if (free_ias) + irias_insert_object(ias_obj); + kfree(ias_opt); break; case IRLMP_IAS_DEL: