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From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
To: casey@schaufler-ca.com
Cc: jmorris@namei.org, linux-kernel@vger.kernel.org,
	serge@hallyn.com, linux-security-module@vger.kernel.org,
	syzbot <syzbot+77c53db50c9fff774e8e@syzkaller.appspotmail.com>,
	syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] WARNING in smk_set_cipso (2)
Date: Mon, 12 Apr 2021 22:28:15 +0900	[thread overview]
Message-ID: <d1d73239-c549-c6c0-5b24-5d701b69e3f1@i-love.sakura.ne.jp> (raw)
In-Reply-To: <000000000000d06f2605bfc110e4@google.com>

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>
---
 security/smack/smackfs.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index 22ded2c26089..1ad7d0d1ea62 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -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))
-- 
2.18.4


  reply	other threads:[~2021-04-12 13:28 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-12  7:00 [syzbot] WARNING in smk_set_cipso (2) syzbot
2021-04-12 13:28 ` Tetsuo Handa [this message]
2021-05-11 16:07   ` Casey Schaufler

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