4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx> commit 4397f04575c44e1440ec2e49b6302785c95fd2f8 upstream. Jing Xia and Chunyan Zhang reported that on failing to allocate part of the tracing buffer, memory is freed, but the pointers that point to them are not initialized back to NULL, and later paths may try to free the freed memory again. Jing and Chunyan fixed one of the locations that does this, but missed a spot. Link: http://lkml.kernel.org/r/20171226071253.8968-1-chunyan.zhang@xxxxxxxxxxxxxx Fixes: 737223fbca3b1 ("tracing: Consolidate buffer allocation code") Reported-by: Jing Xia <jing.xia@xxxxxxxxxxxxxx> Reported-by: Chunyan Zhang <chunyan.zhang@xxxxxxxxxxxxxx> Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- kernel/trace/trace.c | 1 + 1 file changed, 1 insertion(+) --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -6955,6 +6955,7 @@ allocate_trace_buffer(struct trace_array buf->data = alloc_percpu(struct trace_array_cpu); if (!buf->data) { ring_buffer_free(buf->buffer); + buf->buffer = NULL; return -ENOMEM; }