From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Rosenberg Subject: [PATCH v2] drivers/net/cxgb3/cxgb3_main.c: prevent reading uninitialized stack memory Date: Wed, 15 Sep 2010 17:43:12 -0400 Message-ID: <1284586992.6275.93.camel@dan> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, security@kernel.org To: divy@chelsio.com Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Fixed formatting (tabs and line breaks). The CHELSIO_GET_QSET_NUM device ioctl allows unprivileged users to read 4 bytes of uninitialized stack memory, because the "addr" member of the ch_reg struct declared on the stack in cxgb_extension_ioctl() is not altered or zeroed before being copied back to the user. This patch takes care of it. Signed-off-by: Dan Rosenberg --- linux-2.6.35.4.orig/drivers/net/cxgb3/cxgb3_main.c 2010-08-26 19:47:12.000000000 -0400 +++ linux-2.6.35.4/drivers/net/cxgb3/cxgb3_main.c 2010-09-14 21:24:34.369511115 -0400 @@ -2296,6 +2296,8 @@ static int cxgb_extension_ioctl(struct n case CHELSIO_GET_QSET_NUM:{ struct ch_reg edata; + memset(&edata, 0, sizeof(struct ch_reg)); + edata.cmd = CHELSIO_GET_QSET_NUM; edata.val = pi->nqsets; if (copy_to_user(useraddr, &edata, sizeof(edata)))