Messages in this thread Patch in this message | | | Subject | Driver-Core: devtmpfs - reset inode permissions before unlinking | From | Kay Sievers <> | Date | Wed, 13 Jan 2010 14:16:36 +0100 |
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From: Kay Sievers <kay.sievers@vrfy.org> Subject: 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 <kay.sievers@vrfy.org> --- drivers/base/devtmpfs.c | 13 +++++++++++++ 1 file changed, 13 insertions(+)
--- a/drivers/base/devtmpfs.c +++ b/drivers/base/devtmpfs.c @@ -301,6 +301,19 @@ int devtmpfs_delete_node(struct device * 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)
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