Commit 135122f1 authored Apr 12, 2021 by Tetsuo Handa Committed by Greg Kroah-Hartman Jul 19, 2021

smackfs: restrict bytes count in smk_set_cipso()



commit 49ec114a6e62d8d320037ce71c1aaf9650b3cafd upstream.

Oops, I failed to update subject line.

From 07571157c91b98ce1a4aa70967531e64b78e8346 Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Date: Mon, 12 Apr 2021 22:25:06 +0900
Subject: smackfs: restrict bytes count in smk_set_cipso()

Commit 7ef4c19d245f3dc2 ("smackfs: restrict bytes count in smackfs write
functions") missed that count > SMK_CIPSOMAX check applies to only
format == SMK_FIXED24_FMT case.

Reported-by: syzbot <syzbot+77c53db50c9fff774e8e@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent a21e5cb1

security/smack/smackfs.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -855,6 +855,8 @@ static ssize_t smk_set_cipso(struct file file, const char __user buf,
		if (format == SMK_FIXED24_FMT &&
		(count < SMK_CIPSOMIN \|\| count > SMK_CIPSOMAX))
		return -EINVAL;
		if (count > PAGE_SIZE)
		return -EINVAL;

		data = memdup_user_nul(buf, count);
		if (IS_ERR(data))