Commit 9d98e0f4 authored Jul 04, 2019 by Naveen N. Rao Committed by Greg Kroah-Hartman Sep 06, 2019

ftrace: Check for successful allocation of hash

commit 5b0022dd32b7c2e15edf1827ba80aa1407edf9ff upstream.

In register_ftrace_function_probe(), we are not checking the return
value of alloc_and_copy_ftrace_hash(). The subsequent call to
ftrace_match_records() may end up dereferencing the same. Add a check to
ensure this doesn't happen.

Link: http://lkml.kernel.org/r/26e92574f25ad23e7cafa3cf5f7a819de1832cbe.1562249521.git.naveen.n.rao@linux.vnet.ibm.com

Cc: stable@vger.kernel.org
Fixes: 1ec3a81a ("ftrace: Have each function probe use its own ftrace_ops")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent f184b167

kernel/trace/ftrace.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -4317,6 +4317,11 @@ register_ftrace_function_probe(char glob, struct trace_array tr,
		old_hash = *orig_hash;
		hash = alloc_and_copy_ftrace_hash(FTRACE_HASH_DEFAULT_BITS, old_hash);

		if (!hash) {
		ret = -ENOMEM;
		goto out;
		}

		ret = ftrace_match_records(hash, glob, strlen(glob));

		/* Nothing found? */