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From: Ian Kent <raven@themaw.net>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Sasha Levin <sasha.levin@oracle.com>,
	autofs mailing list <autofs@vger.kernel.org>,
	Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: [PATCH] autofs4: check dev ioctl size before allocating
Date: Mon, 07 Apr 2014 09:42:00 +0800	[thread overview]
Message-ID: <20140407014200.5099.51469.stgit@perseus.fritz.box> (raw)

From: Sasha Levin <sasha.levin@oracle.com>

There wasn't any check of the size passed from userspace before
trying to allocate the memory required.

This meant that userspace might request more space than allowed,
triggering an OOM.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Ian Kent <raven@themaw.net>
---
 fs/autofs4/dev-ioctl.c |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c
index 3182c0e..232e03d 100644
--- a/fs/autofs4/dev-ioctl.c
+++ b/fs/autofs4/dev-ioctl.c
@@ -103,6 +103,9 @@ static struct autofs_dev_ioctl *copy_dev_ioctl(struct autofs_dev_ioctl __user *i
 	if (tmp.size < sizeof(tmp))
 		return ERR_PTR(-EINVAL);
 
+	if (tmp.size > (PATH_MAX + sizeof(tmp)))
+		return ERR_PTR(-ENAMETOOLONG);
+
 	return memdup_user(in, tmp.size);
 }
 


             reply	other threads:[~2014-04-07  1:42 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-04-07  1:42 Ian Kent [this message]
  -- strict thread matches above, loose matches on Subject: below --
2014-03-16  1:40 [PATCH] autofs4: check dev ioctl size before allocating Sasha Levin
2014-04-05 15:06 ` Sasha Levin
2014-04-06  3:03   ` Ian Kent
2014-04-06  3:11     ` Sasha Levin
2014-04-06  3:53       ` Ian Kent
2014-04-07  0:03         ` Sasha Levin

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