linux-kernel - [patch] fuse: fix permission checking

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Message-Id: <E1JPxjP-0004sQ-5O@pomaz-ex.szeredi.hu>
Date:	Fri, 15 Feb 2008 11:23:47 +0100
From:	Miklos Szeredi <miklos@...redi.hu>
To:	akpm@...ux-foundation.org
CC:	linux-kernel@...r.kernel.org, stable@...nel.org
Subject: [patch] fuse: fix permission checking

This is for 2.6.25 and 2.6.24.y, but NOT for 2.6.23.y.

Thanks,
Miklos
----

From: Miklos Szeredi <mszeredi@...e.cz>

I added a nasty local variable shadowing bug to fuse in 2.6.24, with
the result, that the 'default_permissions' mount option is basically
ignored.

How did this happen?

 - old err declaration in inner scope
 - new err getting declared in outer scope
 - 'return err' from inner scope getting removed
 - old declaration not being noticed

-Wshadow would have saved us, but it doesn't seem practical for
the kernel :(

More testing would have also saved us :((

Signed-off-by: Miklos Szeredi <mszeredi@...e.cz>
---

Index: linux/fs/fuse/dir.c
===================================================================
--- linux.orig/fs/fuse/dir.c	2008-02-15 10:46:06.000000000 +0100
+++ linux/fs/fuse/dir.c	2008-02-15 11:05:46.000000000 +0100
@@ -906,7 +906,7 @@ static int fuse_permission(struct inode 
 	}
 
 	if (fc->flags & FUSE_DEFAULT_PERMISSIONS) {
-		int err = generic_permission(inode, mask, NULL);
+		err = generic_permission(inode, mask, NULL);
 
 		/* If permission is denied, try to refresh file
 		   attributes.  This is also needed, because the root
--
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