Commit fab8eef8 authored by Amir Goldstein's avatar Amir Goldstein Committed by Darrick J. Wong
Browse files

xfs: sanity check inode mode when creating new dentry 



The helper xfs_dentry_to_name() is used by 2 different
classes of callers: Callers that pass zero mode and don't care
about the returned name.type field and Callers that pass
non zero mode and do care about the name.type field.

Change xfs_dentry_to_name() to not take the mode argument and
change the call sites of the first class to not pass the mode
argument.

Create a new helper xfs_dentry_mode_to_name() which does pass
the mode argument and returns -EFSCORRUPTED if mode is invalid.
Callers that translate non zero mode to on-disk file type now
check the return value and will export the error to user instead
of staging an invalid file type to be written to directory entry.

Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
parent 1fc4d33f

fs/xfs/xfs_iops.c

+39 −9
Original line number Diff line number Diff line
@@ -97,6 +97,16 @@ xfs_init_security( 


static void

xfs_dentry_to_name(

	struct xfs_name	*namep,

	struct dentry	*dentry)

{

	namep->name = dentry->d_name.name;

	namep->len = dentry->d_name.len;

	namep->type = XFS_DIR3_FT_UNKNOWN;

}



static int

xfs_dentry_mode_to_name(

	struct xfs_name	*namep,

	struct dentry	*dentry,

	int		mode)
@@ -104,6 +114,11 @@ xfs_dentry_to_name( 
	namep->name = dentry->d_name.name;

	namep->len = dentry->d_name.len;

	namep->type = xfs_mode_to_ftype(mode);



	if (unlikely(namep->type == XFS_DIR3_FT_UNKNOWN))

		return -EFSCORRUPTED;



	return 0;

}



STATIC void
@@ -119,7 +134,7 @@ xfs_cleanup_inode( 
	 * xfs_init_security we must back out.

	 * ENOSPC can hit here, among other things.

	 */

	xfs_dentry_to_name(&teardown, dentry, 0);

	xfs_dentry_to_name(&teardown, dentry);



	xfs_remove(XFS_I(dir), &teardown, XFS_I(inode));

}
@@ -154,8 +169,12 @@ xfs_generic_create( 
	if (error)

		return error;



	/* Verify mode is valid also for tmpfile case */

	error = xfs_dentry_mode_to_name(&name, dentry, mode);

	if (unlikely(error))

		goto out_free_acl;



	if (!tmpfile) {

		xfs_dentry_to_name(&name, dentry, mode);

		error = xfs_create(XFS_I(dir), &name, mode, rdev, &ip);

	} else {

		error = xfs_create_tmpfile(XFS_I(dir), dentry, mode, &ip);
@@ -248,7 +267,7 @@ xfs_vn_lookup( 
	if (dentry->d_name.len >= MAXNAMELEN)

		return ERR_PTR(-ENAMETOOLONG);



	xfs_dentry_to_name(&name, dentry, 0);

	xfs_dentry_to_name(&name, dentry);

	error = xfs_lookup(XFS_I(dir), &name, &cip, NULL);

	if (unlikely(error)) {

		if (unlikely(error != -ENOENT))
@@ -275,7 +294,7 @@ xfs_vn_ci_lookup( 
	if (dentry->d_name.len >= MAXNAMELEN)

		return ERR_PTR(-ENAMETOOLONG);



	xfs_dentry_to_name(&xname, dentry, 0);

	xfs_dentry_to_name(&xname, dentry);

	error = xfs_lookup(XFS_I(dir), &xname, &ip, &ci_name);

	if (unlikely(error)) {

		if (unlikely(error != -ENOENT))
@@ -310,7 +329,9 @@ xfs_vn_link( 
	struct xfs_name	name;

	int		error;



	xfs_dentry_to_name(&name, dentry, inode->i_mode);

	error = xfs_dentry_mode_to_name(&name, dentry, inode->i_mode);

	if (unlikely(error))

		return error;



	error = xfs_link(XFS_I(dir), XFS_I(inode), &name);

	if (unlikely(error))
@@ -329,7 +350,7 @@ xfs_vn_unlink( 
	struct xfs_name	name;

	int		error;



	xfs_dentry_to_name(&name, dentry, 0);

	xfs_dentry_to_name(&name, dentry);



	error = xfs_remove(XFS_I(dir), &name, XFS_I(d_inode(dentry)));

	if (error)
@@ -359,7 +380,9 @@ xfs_vn_symlink( 


	mode = S_IFLNK |

		(irix_symlink_mode ? 0777 & ~current_umask() : S_IRWXUGO);

	xfs_dentry_to_name(&name, dentry, mode);

	error = xfs_dentry_mode_to_name(&name, dentry, mode);

	if (unlikely(error))

		goto out;



	error = xfs_symlink(XFS_I(dir), &name, symname, mode, &cip);

	if (unlikely(error))
@@ -395,6 +418,7 @@ xfs_vn_rename( 
{

	struct inode	*new_inode = d_inode(ndentry);

	int		omode = 0;

	int		error;

	struct xfs_name	oname;

	struct xfs_name	nname;
@@ -405,8 +429,14 @@ xfs_vn_rename( 
	if (flags & RENAME_EXCHANGE)

		omode = d_inode(ndentry)->i_mode;



	xfs_dentry_to_name(&oname, odentry, omode);

	xfs_dentry_to_name(&nname, ndentry, d_inode(odentry)->i_mode);

	error = xfs_dentry_mode_to_name(&oname, odentry, omode);

	if (omode && unlikely(error))

		return error;



	error = xfs_dentry_mode_to_name(&nname, ndentry,

					d_inode(odentry)->i_mode);

	if (unlikely(error))

		return error;



	return xfs_rename(XFS_I(odir), &oname, XFS_I(d_inode(odentry)),

			  XFS_I(ndir), &nname,

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