diff options
Diffstat (limited to 'drivers/scsi/sd.c')
| -rw-r--r-- | drivers/scsi/sd.c | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 03fcbab30033..6b967a05c8c1 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -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, 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, @@ -1357,7 +1362,7 @@ 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, @@ -1402,6 +1407,8 @@ 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); @@ -1414,6 +1421,12 @@ 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; @@ -1472,7 +1485,7 @@ 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"); |