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Commit 5e31d76f authored by Kay Sievers's avatar Kay Sievers Committed by Greg Kroah-Hartman
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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: default avatarKay Sievers <kay.sievers@vrfy.org>
Cc: stable <stable@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 0933e2d9

drivers/base/devtmpfs.c

+13 −0
Original line number Diff line number Diff line
@@ -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)