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From:   Jim Cromie <jim.cromie@gmail.com>
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Subject: [re: PATCH v2 00/15 -  04/11] dyndbg: fix old BUG_ON in >control parser
Date:   Thu,  7 Dec 2023 17:15:07 -0700
Message-ID: <3f7fa537d49fbd96ffae84f62029bd9e56e99d5a.1701993656.git.jim.cromie@gmail.com>
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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 bde96ad867c6..2ac1bd7f105f 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -660,7 +660,11 @@ 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