[PATCH 4.7 31/69] fix memory leaks in tracing_buffers_splice_read()

[Greg Kroah-Hartman]

4.7-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Al Viro <v...@zeniv.linux.org.uk>

commit 1ae2293dd6d2f5c823cf97e60b70d03631cd622f upstream.

Signed-off-by: Al Viro <v...@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 kernel/trace/trace.c |   14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -5929,9 +5929,6 @@ tracing_buffers_splice_read(struct file
                return -EBUSY;
 #endif
 
-       if (splice_grow_spd(pipe, &spd))
-               return -ENOMEM;
-
        if (*ppos & (PAGE_SIZE - 1))
                return -EINVAL;
 
@@ -5941,6 +5938,9 @@ tracing_buffers_splice_read(struct file
                len &= PAGE_MASK;
        }
 
+       if (splice_grow_spd(pipe, &spd))
+               return -ENOMEM;
+
  again:
        trace_access_lock(iter->cpu_file);
        entries = ring_buffer_entries_cpu(iter->trace_buffer->buffer, 
iter->cpu_file);
@@ -5998,19 +5998,21 @@ tracing_buffers_splice_read(struct file
        /* did we read anything? */
        if (!spd.nr_pages) {
                if (ret)
-                       return ret;
+                       goto out;
 
+               ret = -EAGAIN;
                if ((file->f_flags & O_NONBLOCK) || (flags & SPLICE_F_NONBLOCK))
-                       return -EAGAIN;
+                       goto out;
 
                ret = wait_on_pipe(iter, true);
                if (ret)
-                       return ret;
+                       goto out;
 
                goto again;
        }
 
        ret = splice_to_pipe(pipe, &spd);
+out:
        splice_shrink_spd(&spd);
 
        return ret;