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-rw-r--r--drivers/scsi/sd.c20
1 files changed, 17 insertions, 3 deletions
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 930db39..9d98723 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -89,6 +89,11 @@
#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 {
@@ -1239,7 +1244,7 @@ sd_do_mode_sense(struct scsi_device *sdp, int dbd, int modepage,
/*
* 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,
@@ -1297,7 +1302,7 @@ sd_read_write_protect_flag(struct scsi_disk *sdkp, char *diskname,
/*
* 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,
@@ -1342,6 +1347,8 @@ sd_read_cache_type(struct scsi_disk *sdkp, char *diskname,
/* 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);
@@ -1354,6 +1361,12 @@ sd_read_cache_type(struct scsi_disk *sdkp, char *diskname,
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;
@@ -1398,6 +1411,7 @@ defaults:
diskname);
sdkp->WCE = 0;
sdkp->RCD = 0;
+ sdkp->DPOFUA = 0;
}
/**
@@ -1421,7 +1435,7 @@ static int sd_revalidate_disk(struct gendisk *disk)
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");