tracing: Check for allocation failure in __tracing_open()

Clean up and return -ENOMEM on if the kzalloc() fails.

This also prevents a potential crash, as the pointer that failed to
allocate would be later used.

Link: http://lkml.kernel.org/r/20120711063507.GF11812@elgon.mountain
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 814ff30..a120f98 100644 (file)
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2390,6 +2390,9 @@ __tracing_open(struct inode *inode, struct file *file)
 
        iter->buffer_iter = kzalloc(sizeof(*iter->buffer_iter) * num_possible_cpus(),
                                    GFP_KERNEL);
+       if (!iter->buffer_iter)
+               goto release;
+
        /*
         * We make a copy of the current tracer to avoid concurrent
         * changes on it while we are reading.
@@ -2451,6 +2454,7 @@ __tracing_open(struct inode *inode, struct file *file)
        mutex_unlock(&trace_types_lock);
        kfree(iter->trace);
        kfree(iter->buffer_iter);
+release:
        seq_release_private(inode, file);
        return ERR_PTR(-ENOMEM);
 }