From: Kay Sievers Date: Wed, 13 Jan 2010 13:16:36 +0000 (+0100) Subject: Driver-Core: devtmpfs - reset inode permissions before unlinking X-Git-Tag: v2.6.34-rc1~1^2~43 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=5e31d76f2817bd50258a092a7c5b15b3006fd61c;p=platform%2Fkernel%2Flinux-stable.git Driver-Core: devtmpfs - reset inode permissions before unlinking Before unlinking the inode, reset the current permissions of possible references like hardlinks, so granted permissions can not be retained across the device lifetime by creating hardlinks, in the unusual case that there is a user-writable directory on the same filesystem. Signed-off-by: Kay Sievers Cc: stable Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c index 42ae452..dac478c 100644 --- a/drivers/base/devtmpfs.c +++ b/drivers/base/devtmpfs.c @@ -301,6 +301,19 @@ int devtmpfs_delete_node(struct device *dev) if (dentry->d_inode) { err = vfs_getattr(nd.path.mnt, dentry, &stat); if (!err && dev_mynode(dev, dentry->d_inode, &stat)) { + struct iattr newattrs; + /* + * before unlinking this node, reset permissions + * of possible references like hardlinks + */ + newattrs.ia_uid = 0; + newattrs.ia_gid = 0; + newattrs.ia_mode = stat.mode & ~0777; + newattrs.ia_valid = + ATTR_UID|ATTR_GID|ATTR_MODE; + mutex_lock(&dentry->d_inode->i_mutex); + notify_change(dentry, &newattrs); + mutex_unlock(&dentry->d_inode->i_mutex); err = vfs_unlink(nd.path.dentry->d_inode, dentry); if (!err || err == -ENOENT)