2 files changed, 5 insertions, 3 deletions

diff --git a/block/blk-core.c b/block/blk-core.c
index 29bcfac6c688..859879d0a0bf 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -132,6 +132,7 @@ void blk_rq_init(struct request_queue *q, struct request *rq)
         INIT_HLIST_NODE(&rq->hash);
         RB_CLEAR_NODE(&rq->rb_node);
         rq->cmd = rq->__cmd;
+        rq->cmd_len = BLK_MAX_CDB;
         rq->tag = -1;
         rq->ref_count = 1;
 }
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 947c5b3f90c4..b32ff446c3fb 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -327,10 +327,10 @@ static ssize_t blk_msg_write(struct file *filp, const char __user *buffer,
         char *msg;
         struct blk_trace *bt;
 
-        if (count > BLK_TN_MAX_MSG)
+        if (count >= BLK_TN_MAX_MSG)
                 return -EINVAL;
 
-        msg = kmalloc(count, GFP_KERNEL);
+        msg = kmalloc(count + 1, GFP_KERNEL);
         if (msg == NULL)
                 return -ENOMEM;
 
@@ -339,6 +339,7 @@ static ssize_t blk_msg_write(struct file *filp, const char __user *buffer,
                 return -EFAULT;
         }
 
+        msg[count] = '\0';
         bt = filp->private_data;
         __trace_note_message(bt, "%s", msg);
         kfree(msg);
@@ -642,7 +643,7 @@ static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
         if (blk_pc_request(rq)) {
                 what |= BLK_TC_ACT(BLK_TC_PC);
                 __blk_add_trace(bt, 0, rq->data_len, rw, what, rq->errors,
-                                sizeof(rq->cmd), rq->cmd);
+                                rq->cmd_len, rq->cmd);
         } else  {
                 what |= BLK_TC_ACT(BLK_TC_FS);
                 __blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9,