[3.16.y-ckt stable] Patch "autofs4 copy_dev_ioctl(): keep the value of ->size we'd used for allocation" has been added to staging queue

Luis Henriques luis.henriques at canonical.com
Mon Mar 2 13:38:16 UTC 2015

This is a note to let you know that I have just added a patch titled

    autofs4 copy_dev_ioctl(): keep the value of ->size we'd used for allocation

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:


This patch is scheduled to be released in version 3.16.7-ckt8.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see



>From 1f0a452ef4f25c1044dd5c33ddfc46f2622dd990 Mon Sep 17 00:00:00 2001
From: Al Viro <viro at zeniv.linux.org.uk>
Date: Sat, 21 Feb 2015 22:19:57 -0500
Subject: autofs4 copy_dev_ioctl(): keep the value of ->size we'd used for

commit 0a280962dc6e117e0e4baa668453f753579265d9 upstream.

X-Coverup: just ask spender
Signed-off-by: Al Viro <viro at zeniv.linux.org.uk>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
 fs/autofs4/dev-ioctl.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c
index 5b570b6efa28..9fae6e8a4c7e 100644
--- a/fs/autofs4/dev-ioctl.c
+++ b/fs/autofs4/dev-ioctl.c
@@ -95,7 +95,7 @@ static int check_dev_ioctl_version(int cmd, struct autofs_dev_ioctl *param)
 static struct autofs_dev_ioctl *copy_dev_ioctl(struct autofs_dev_ioctl __user *in)
-	struct autofs_dev_ioctl tmp;
+	struct autofs_dev_ioctl tmp, *res;

 	if (copy_from_user(&tmp, in, sizeof(tmp)))
 		return ERR_PTR(-EFAULT);
@@ -106,7 +106,11 @@ static struct autofs_dev_ioctl *copy_dev_ioctl(struct autofs_dev_ioctl __user *i
 	if (tmp.size > (PATH_MAX + sizeof(tmp)))

-	return memdup_user(in, tmp.size);
+	res = memdup_user(in, tmp.size);
+	if (!IS_ERR(res))
+		res->size = tmp.size;
+	return res;

 static inline void free_dev_ioctl(struct autofs_dev_ioctl *param)

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