[PATCH 2/2] overlayfs: switch to use inode_only_permissions

From: Andy Whitcroft
Date: Tue Mar 06 2012 - 11:18:28 EST


When checking permissions on an overlayfs inode we do not take into
account either device cgroup restrictions nor security permissions.
This allows a user to mount an overlayfs layer over a restricted device
directory and by pass those permissions to open otherwise restricted
files.

Switch over to the newly introduced inode_only_permissions.

Signed-off-by: Andy Whitcroft <apw@xxxxxxxxxxxxx>
---
fs/overlayfs/inode.c | 5 +----
1 files changed, 1 insertions(+), 4 deletions(-)

diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index ba1a777..1e3d157 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -114,10 +114,7 @@ int ovl_permission(struct inode *inode, int mask)
goto out_dput;
}

- if (realinode->i_op->permission)
- err = realinode->i_op->permission(realinode, mask);
- else
- err = generic_permission(realinode, mask);
+ err = inode_only_permission(realinode, mask);
out_dput:
dput(alias);
return err;
--
1.7.9

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/