Received-SPF: pass (google.com: domain of linux-kernel+bounces-10177-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.80.249 as permitted sender) client-ip=147.75.80.249;
From: =?UTF-8?q?=C5=81ukasz=20Bartosik?= <lb@semihalf.com>
To: Jason Baron <jbaron@akamai.com>,
	Jim Cromie <jim.cromie@gmail.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Kees Cook <keescook@chromium.org>,
	Douglas Anderson <dianders@chromium.org>
Cc: Guenter Roeck <groeck@google.com>,
	Yaniv Tzoreff <yanivt@google.com>,
	Benson Leung <bleung@google.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Vincent Whitchurch <vincent.whitchurch@axis.com>,
	Pekka Paalanen <ppaalanen@gmail.com>,
	Sean Paul <seanpaul@chromium.org>,
	Daniel Vetter <daniel@ffwll.ch>,
	Simon Ser <contact@emersion.fr>,
	John Ogness <john.ogness@linutronix.de>,
	Petr Mladek <pmladek@suse.com>,
	Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
	linux-kernel@vger.kernel.org,
	upstream@semihalf.com
Subject: [PATCH v3 17/22] dyndbg: fix old BUG_ON in >control parser
Date: Sat, 23 Dec 2023 02:51:26 +0100
Message-ID: <20231223015131.2836090-18-lb@semihalf.com>
In-Reply-To: <20231223015131.2836090-1-lb@semihalf.com>
References: <20231223015131.2836090-1-lb@semihalf.com>
Precedence: bulk
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit

From: Jim Cromie <jim.cromie@gmail.com>

Fix a BUG_ON from 2009.  I have hit it while fuzzing >control on some
other patches, and panic from user input is bad.  Replace the BUG_ON
with pr_error and return -EINVAL.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 lib/dynamic_debug.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 8ce485fc84ff..d4e50e4f6635 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -650,7 +650,11 @@ static int ddebug_tokenize(char *buf, char *words[], int maxwords)
 		} else {
 			for (end = buf; *end && !isspace(*end); end++)
 				;
-			BUG_ON(end == buf);
+			if (end == buf) {
+				pr_err("parse err after word:%d=%s\n", nwords,
+				       nwords ? words[nwords - 1] : "<none>");
+				return -EINVAL;
+			}
 		}
 
 		/* `buf' is start of word, `end' is one past its end */
-- 
2.43.0.472.g3155946c3a-goog