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 <[email protected]>
Also removed the buffer size magic number (512) and added DPOFUA of
zero to the defaults
Signed-off-by: James Bottomley <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
rediff for 2.6.15.x without DPOFUA bit, taken from commit
489708007785389941a89fa06aedc5ec53303c96
Signed-off-by: Stefan Richter <[email protected]>
---
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 [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
