Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932270AbWBZXSl (ORCPT ); Sun, 26 Feb 2006 18:18:41 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932255AbWBZXRt (ORCPT ); Sun, 26 Feb 2006 18:17:49 -0500 Received: from einhorn.in-berlin.de ([192.109.42.8]:6035 "EHLO einhorn.in-berlin.de") by vger.kernel.org with ESMTP id S932301AbWBZXRs (ORCPT ); Sun, 26 Feb 2006 18:17:48 -0500 X-Envelope-From: stefanr@s5r6.in-berlin.de Date: Mon, 27 Feb 2006 00:16:10 +0100 (CET) From: Stefan Richter Subject: [PATCH 2.6.15.4 update] sd: fix memory corruption with broken mode page headers To: stable@kernel.org cc: linux-kernel@vger.kernel.org, Al Viro , James Bottomley In-Reply-To: <4400E34B.1000400@s5r6.in-berlin.de> Message-ID: References: <20060225021009.GV3883@sorel.sous-sol.org> <4400E34B.1000400@s5r6.in-berlin.de> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; CHARSET=us-ascii Content-Disposition: INLINE X-Spam-Score: (0.735) AWL,BAYES_50 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3250 Lines: 95 sd: fix memory corruption with broken mode page headers There's a problem in sd where we blindly believe the length of the headers and block descriptors. Some devices return insane values for these and cause our length to end up greater than the actual buffer size, so check to make sure. Signed-off-by: Al Viro Also removed the buffer size magic number (512) and added DPOFUA of zero to the defaults Signed-off-by: James Bottomley Signed-off-by: Linus Torvalds rediff for 2.6.15.x without DPOFUA bit, taken from commit 489708007785389941a89fa06aedc5ec53303c96 Signed-off-by: Stefan Richter --- fixes http://bugzilla.kernel.org/show_bug.cgi?id=6114 and http://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=182005 Index: linux-2.6.15.4/drivers/scsi/sd.c =================================================================== --- linux-2.6.15.4.orig/drivers/scsi/sd.c 2006-02-26 23:58:40.000000000 +0100 +++ linux-2.6.15.4/drivers/scsi/sd.c 2006-02-27 00:03:07.000000000 +0100 @@ -88,6 +88,11 @@ #define SD_MAX_RETRIES 5 #define SD_PASSTHROUGH_RETRIES 1 +/* + * Size of the initial data buffer for mode and read capacity data + */ +#define SD_BUF_SIZE 512 + static void scsi_disk_release(struct kref *kref); struct scsi_disk { @@ -1299,7 +1304,7 @@ sd_do_mode_sense(struct scsi_device *sdp /* * read write protect setting, if possible - called only in sd_revalidate_disk() - * called with buffer of length 512 + * called with buffer of length SD_BUF_SIZE */ static void sd_read_write_protect_flag(struct scsi_disk *sdkp, char *diskname, @@ -1357,7 +1362,7 @@ sd_read_write_protect_flag(struct scsi_d /* * sd_read_cache_type - called only from sd_revalidate_disk() - * called with buffer of length 512 + * called with buffer of length SD_BUF_SIZE */ static void sd_read_cache_type(struct scsi_disk *sdkp, char *diskname, @@ -1402,6 +1407,8 @@ sd_read_cache_type(struct scsi_disk *sdk /* Take headers and block descriptors into account */ len += data.header_length + data.block_descriptor_length; + if (len > SD_BUF_SIZE) + goto bad_sense; /* Get the data */ res = sd_do_mode_sense(sdp, dbd, modepage, buffer, len, &data, &sshdr); @@ -1414,6 +1421,12 @@ sd_read_cache_type(struct scsi_disk *sdk int ct = 0; int offset = data.header_length + data.block_descriptor_length; + if (offset >= SD_BUF_SIZE - 2) { + printk(KERN_ERR "%s: malformed MODE SENSE response", + diskname); + goto defaults; + } + if ((buffer[offset] & 0x3f) != modepage) { printk(KERN_ERR "%s: got wrong page\n", diskname); goto defaults; @@ -1472,7 +1485,7 @@ static int sd_revalidate_disk(struct gen if (!scsi_device_online(sdp)) goto out; - buffer = kmalloc(512, GFP_KERNEL | __GFP_DMA); + buffer = kmalloc(SD_BUF_SIZE, GFP_KERNEL | __GFP_DMA); if (!buffer) { printk(KERN_WARNING "(sd_revalidate_disk:) Memory allocation " "failure.\n"); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/