[PATCH 3.10 101/319] fix memory leaks in tracing_buffers_splice_read()

Willy Tarreau
2017-02-05T19:26:03Z

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

commit 1ae2293dd6d2f5c823cf97e60b70d03631cd622f upstream.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Willy Tarreau <w@1wt.eu>
---
kernel/trace/trace.c | 17 +++++++++--------
1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index eff26a9..4ff36f7 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -5168,11 +5168,6 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
}
#endif

- if (splice_grow_spd(pipe, &spd)) {
- ret = -ENOMEM;
- goto out;
- }
-
if (*ppos & (PAGE_SIZE - 1)) {
ret = -EINVAL;
goto out;
@@ -5186,6 +5181,11 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
len &= PAGE_MASK;
}

+ if (splice_grow_spd(pipe, &spd)) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
again:
trace_access_lock(iter->cpu_file);
entries = ring_buffer_entries_cpu(iter->trace_buffer->buffer, iter->cpu_file);
@@ -5241,21 +5241,22 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
if (!spd.nr_pages) {
if ((file->f_flags & O_NONBLOCK) || (flags & SPLICE_F_NONBLOCK)) {
ret = -EAGAIN;
- goto out;
+ goto out_shrink;
}
mutex_unlock(&trace_types_lock);
ret = iter->trace->wait_pipe(iter);
mutex_lock(&trace_types_lock);
if (ret)
- goto out;
+ goto out_shrink;
if (signal_pending(current)) {
ret = -EINTR;
- goto out;
+ goto out_shrink;
}
goto again;
}

ret = splice_to_pipe(pipe, &spd);
+out_shrink:
splice_shrink_spd(&spd);
out:
mutex_unlock(&trace_types_lock);
--
2.8.0.rc2.1.gbe9624a