From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Alan Stern , Dmitry Vyukov , James Bottomley Subject: [ 010/117] SCSI: sd: Fix potential out-of-bounds access Date: Tue, 24 Sep 2013 17:17:56 -0700 Message-Id: <20130925001741.988849176@linuxfoundation.org> In-Reply-To: <20130925001740.833541979@linuxfoundation.org> References: <20130925001740.833541979@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alan Stern commit 984f1733fcee3fbc78d47e26c5096921c5d9946a upstream. This patch fixes an out-of-bounds error in sd_read_cache_type(), found by Google's AddressSanitizer tool. When the loop ends, we know that "offset" lies beyond the end of the data in the buffer, so no Caching mode page was found. In theory it may be present, but the buffer size is limited to 512 bytes. Signed-off-by: Alan Stern Reported-by: Dmitry Vyukov Signed-off-by: James Bottomley Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/sd.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -2419,14 +2419,9 @@ sd_read_cache_type(struct scsi_disk *sdk } } - if (modepage == 0x3F) { - sd_printk(KERN_ERR, sdkp, "No Caching mode page " - "present\n"); - goto defaults; - } else if ((buffer[offset] & 0x3f) != modepage) { - sd_printk(KERN_ERR, sdkp, "Got wrong page\n"); - goto defaults; - } + sd_printk(KERN_ERR, sdkp, "No Caching mode page found\n"); + goto defaults; + Page_found: if (modepage == 8) { sdkp->WCE = ((buffer[offset + 2] & 0x04) != 0);