KVM: PPC: Use preregistered memory API to access TCE list

[mirror_ubuntu-zesty-kernel.git] / drivers / scsi / sr.c

diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index 94352e4df831be803c3ef6a76cf7f6177750f29c..94b0aacefae663748409157df53d0718c257d889 100644 (file)
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -833,6 +833,7 @@ static void get_capabilities(struct scsi_cd *cd)
        unsigned char *buffer;
        struct scsi_mode_data data;
        struct scsi_sense_hdr sshdr;
+       unsigned int ms_len = 128;
        int rc, n;
 
        static const char *loadmech[] =
@@ -859,10 +860,11 @@ static void get_capabilities(struct scsi_cd *cd)
        scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
 
        /* ask for mode page 0x2a */
-       rc = scsi_mode_sense(cd->device, 0, 0x2a, buffer, 128,
+       rc = scsi_mode_sense(cd->device, 0, 0x2a, buffer, ms_len,
                             SR_TIMEOUT, 3, &data, NULL);
 
-       if (!scsi_status_is_good(rc)) {
+       if (!scsi_status_is_good(rc) || data.length > ms_len ||
+           data.header_length + data.block_descriptor_length > data.length) {
                /* failed, drive doesn't have capabilities mode page */
                cd->cdi.speed = 1;
                cd->cdi.mask |= (CDC_CD_R | CDC_CD_RW | CDC_DVD_R |