Commit ea0b3e81 authored by Darrick J. Wong's avatar Darrick J. Wong
Browse files

xfs: enforce one namespace per attribute 



Create a standardized helper function to enforce one namespace bit per
extended attribute, and refactor all the open-coded hweight logic.  This
function is not a static inline to avoid porting hassles in userspace.

Signed-off-by: default avatarDarrick J. Wong <djwong@kernel.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
parent ffdcc3b8

fs/xfs/libxfs/xfs_attr.c

+11 −0
Original line number Diff line number Diff line
@@ -1532,12 +1532,23 @@ xfs_attr_node_get( 
	return error;

}



/* Enforce that there is at most one namespace bit per attr. */

inline bool xfs_attr_check_namespace(unsigned int attr_flags)

{

	return hweight32(attr_flags & XFS_ATTR_NSP_ONDISK_MASK) < 2;

}



/* Returns true if the attribute entry name is valid. */

bool

xfs_attr_namecheck(

	unsigned int	attr_flags,

	const void	*name,

	size_t		length)

{

	/* Only one namespace bit allowed. */

	if (!xfs_attr_check_namespace(attr_flags))

		return false;



	/*

	 * MAXNAMELEN includes the trailing null, but (name/length) leave it

	 * out, so use >= for the length check.

fs/xfs/libxfs/xfs_attr.h

+3 −1
Original line number Diff line number Diff line
@@ -560,7 +560,9 @@ enum xfs_attr_update { 
int xfs_attr_set(struct xfs_da_args *args, enum xfs_attr_update op);

int xfs_attr_set_iter(struct xfs_attr_intent *attr);

int xfs_attr_remove_iter(struct xfs_attr_intent *attr);

bool xfs_attr_namecheck(const void *name, size_t length);

bool xfs_attr_check_namespace(unsigned int attr_flags);

bool xfs_attr_namecheck(unsigned int attr_flags, const void *name,

		size_t length);

int xfs_attr_calc_size(struct xfs_da_args *args, int *local);

void xfs_init_attr_trans(struct xfs_da_args *args, struct xfs_trans_res *tres,

			 unsigned int *total);

fs/xfs/libxfs/xfs_attr_leaf.c

+6 −1
Original line number Diff line number Diff line
@@ -950,6 +950,11 @@ xfs_attr_shortform_to_leaf( 
		nargs.hashval = xfs_da_hashname(sfe->nameval,

						sfe->namelen);

		nargs.attr_filter = sfe->flags & XFS_ATTR_NSP_ONDISK_MASK;

		if (!xfs_attr_check_namespace(sfe->flags)) {

			xfs_da_mark_sick(args);

			error = -EFSCORRUPTED;

			goto out;

		}

		error = xfs_attr3_leaf_lookup_int(bp, &nargs); /* set a->index */

		ASSERT(error == -ENOATTR);

		error = xfs_attr3_leaf_add(bp, &nargs);
@@ -1063,7 +1068,7 @@ xfs_attr_shortform_verify( 
		 * one namespace flag per xattr, so we can just count the

		 * bits (i.e. hweight) here.

		 */

		if (hweight8(sfep->flags & XFS_ATTR_NSP_ONDISK_MASK) > 1)

		if (!xfs_attr_check_namespace(sfep->flags))

			return __this_address;



		sfep = next_sfep;

fs/xfs/scrub/attr.c

+5 −7
Original line number Diff line number Diff line
@@ -203,14 +203,8 @@ xchk_xattr_actor( 
		return 0;

	}



	/* Only one namespace bit allowed. */

	if (hweight32(attr_flags & XFS_ATTR_NSP_ONDISK_MASK) > 1) {

		xchk_fblock_set_corrupt(sc, XFS_ATTR_FORK, args.blkno);

		return -ECANCELED;

	}



	/* Does this name make sense? */

	if (!xfs_attr_namecheck(name, namelen)) {

	if (!xfs_attr_namecheck(attr_flags, name, namelen)) {

		xchk_fblock_set_corrupt(sc, XFS_ATTR_FORK, args.blkno);

		return -ECANCELED;

	}
@@ -519,6 +513,10 @@ xchk_xattr_rec( 
		xchk_da_set_corrupt(ds, level);

		return 0;

	}

	if (!xfs_attr_check_namespace(ent->flags)) {

		xchk_da_set_corrupt(ds, level);

		return 0;

	}



	if (ent->flags & XFS_ATTR_LOCAL) {

		lentry = (struct xfs_attr_leaf_name_local *)

fs/xfs/scrub/attr_repair.c

+1 −3
Original line number Diff line number Diff line
@@ -123,12 +123,10 @@ xrep_xattr_want_salvage( 
		return false;

	if (namelen > XATTR_NAME_MAX || namelen <= 0)

		return false;

	if (!xfs_attr_namecheck(name, namelen))

	if (!xfs_attr_namecheck(attr_flags, name, namelen))

		return false;

	if (valuelen > XATTR_SIZE_MAX || valuelen < 0)

		return false;

	if (hweight32(attr_flags & XFS_ATTR_NSP_ONDISK_MASK) > 1)

		return false;

	return true;

}