stable.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Jim Cromie <jim.cromie@gmail.com>
To: gregkh@linuxfoundation.org
Cc: Jim Cromie <jim.cromie@gmail.com>,
	stable@vger.kernel.org, Jason Baron <jbaron@akamai.com>,
	linux-kernel@vger.kernel.org
Subject: [PATCH v2] dyndbg: fix use before null check
Date: Wed,  9 Dec 2020 11:36:25 -0700	[thread overview]
Message-ID: <20201209183625.2432329-1-jim.cromie@gmail.com> (raw)

In commit a2d375eda771 ("dyndbg: refine export, rename to
dynamic_debug_exec_queries()"), a string is copied before checking it
isn't NULL.  Fix this, report a usage/interface error, and return the
proper error code.

Fixes: a2d375eda771 ("dyndbg: refine export, rename to dynamic_debug_exec_queries()")
Cc: stable@vger.kernel.org
--
-v2 drop comment tweak, improve commit message

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
---
 lib/dynamic_debug.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index bd7b3aaa93c3..c70d6347afa2 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -561,9 +561,14 @@ static int ddebug_exec_queries(char *query, const char *modname)
 int dynamic_debug_exec_queries(const char *query, const char *modname)
 {
 	int rc;
-	char *qry = kstrndup(query, PAGE_SIZE, GFP_KERNEL);
+	char *qry; /* writable copy of query */
 
-	if (!query)
+	if (!query) {
+		pr_err("non-null query/command string expected\n");
+		return -EINVAL;
+	}
+	qry = kstrndup(query, PAGE_SIZE, GFP_KERNEL);
+	if (!qry)
 		return -ENOMEM;
 
 	rc = ddebug_exec_queries(qry, modname);
-- 
2.29.2


                 reply	other threads:[~2020-12-09 18:37 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20201209183625.2432329-1-jim.cromie@gmail.com \
    --to=jim.cromie@gmail.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=jbaron@akamai.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=stable@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).