[PATCH 4.4 53/73] fix memory leaks in tracing_buffers_splice_read()

Greg Kroah-Hartman
2016-09-28T09:09:40Z

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

commit 1ae2293dd6d2f5c823cf97e60b70d03631cd622f upstream.

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

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

--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -5766,9 +5766,6 @@ tracing_buffers_splice_read(struct file
return -EBUSY;
#endif

- if (splice_grow_spd(pipe, &spd))
- return -ENOMEM;
-
if (*ppos & (PAGE_SIZE - 1))
return -EINVAL;

@@ -5778,6 +5775,9 @@ 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);
@@ -5835,19 +5835,21 @@ 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;