Merge tag 'xfs-4.11-fixes-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull XFS fixes from Darrick Wong:
"Here are three more fixes for 4.11.

The first one reworks the inline directory verifier to check the
working copy of the directory metadata and to avoid triggering a
periodic crash in xfs/348. The second patch fixes a regression in hole
punching at EOF that corrupts files; and the third patch closes a
kernel memory disclosure bug.

Summary:

- rework the inline directory verifier to avoid crashes on disk
corruption

- don't change file size when punching holes w/ KEEP_SIZE

- close a kernel memory exposure bug"

* tag 'xfs-4.11-fixes-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
xfs: fix kernel memory exposure problems
xfs: Honor FALLOC_FL_KEEP_SIZE when punching ends of files
xfs: rework the inline directory verifiers

fs/xfs/libxfs/xfs_dir2_priv.h

···
 extern int xfs_dir2_sf_lookup(struct xfs_da_args *args);
 extern int xfs_dir2_sf_removename(struct xfs_da_args *args);
 extern int xfs_dir2_sf_replace(struct xfs_da_args *args);
-extern int xfs_dir2_sf_verify(struct xfs_mount *mp, struct xfs_dir2_sf_hdr *sfp,
-		int size);
+extern int xfs_dir2_sf_verify(struct xfs_inode *ip);
 
 /* xfs_dir2_readdir.c */
 extern int xfs_readdir(struct xfs_inode *dp, struct dir_context *ctx,

fs/xfs/libxfs/xfs_dir2_sf.c

···
 /* Verify the consistency of an inline directory. */
 int
 xfs_dir2_sf_verify(
-	struct xfs_mount		*mp,
-	struct xfs_dir2_sf_hdr		*sfp,
-	int				size)
+	struct xfs_inode		*ip)
 {
+	struct xfs_mount		*mp = ip->i_mount;
+	struct xfs_dir2_sf_hdr		*sfp;
 	struct xfs_dir2_sf_entry	*sfep;
 	struct xfs_dir2_sf_entry	*next_sfep;
 	char				*endp;
 	const struct xfs_dir_ops	*dops;
+	struct xfs_ifork		*ifp;
 	xfs_ino_t			ino;
 	int				i;
 	int				i8count;
 	int				offset;
+	int				size;
+	int				error;
 	__uint8_t			filetype;
 
+	ASSERT(ip->i_d.di_format == XFS_DINODE_FMT_LOCAL);
+	/*
+	 * xfs_iread calls us before xfs_setup_inode sets up ip->d_ops,
+	 * so we can only trust the mountpoint to have the right pointer.
+	 */
 	dops = xfs_dir_get_ops(mp, NULL);
+
+	ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
+	sfp = (struct xfs_dir2_sf_hdr *)ifp->if_u1.if_data;
+	size = ifp->if_bytes;
 
 	/*
 	 * Give up if the directory is way too short.
 	 */
-	XFS_WANT_CORRUPTED_RETURN(mp, size >
-			offsetof(struct xfs_dir2_sf_hdr, parent));
-	XFS_WANT_CORRUPTED_RETURN(mp, size >=
-			xfs_dir2_sf_hdr_size(sfp->i8count));
+	if (size <= offsetof(struct xfs_dir2_sf_hdr, parent) ||
+	    size < xfs_dir2_sf_hdr_size(sfp->i8count))
+		return -EFSCORRUPTED;
 
 	endp = (char *)sfp + size;
 
 	/* Check .. entry */
 	ino = dops->sf_get_parent_ino(sfp);
 	i8count = ino > XFS_DIR2_MAX_SHORT_INUM;
-	XFS_WANT_CORRUPTED_RETURN(mp, !xfs_dir_ino_validate(mp, ino));
+	error = xfs_dir_ino_validate(mp, ino);
+	if (error)
+		return error;
 	offset = dops->data_first_offset;
 
 	/* Check all reported entries */
···
 		 * Check the fixed-offset parts of the structure are
 		 * within the data buffer.
 		 */
-		XFS_WANT_CORRUPTED_RETURN(mp,
-				((char *)sfep + sizeof(*sfep)) < endp);
+		if (((char *)sfep + sizeof(*sfep)) >= endp)
+			return -EFSCORRUPTED;
 
 		/* Don't allow names with known bad length. */
-		XFS_WANT_CORRUPTED_RETURN(mp, sfep->namelen > 0);
-		XFS_WANT_CORRUPTED_RETURN(mp, sfep->namelen < MAXNAMELEN);
+		if (sfep->namelen == 0)
+			return -EFSCORRUPTED;
 
 		/*
 		 * Check that the variable-length part of the structure is
···
 		 * name component, so nextentry is an acceptable test.
 		 */
 		next_sfep = dops->sf_nextentry(sfp, sfep);
-		XFS_WANT_CORRUPTED_RETURN(mp, endp >= (char *)next_sfep);
+		if (endp < (char *)next_sfep)
+			return -EFSCORRUPTED;
 
 		/* Check that the offsets always increase. */
-		XFS_WANT_CORRUPTED_RETURN(mp,
-				xfs_dir2_sf_get_offset(sfep) >= offset);
+		if (xfs_dir2_sf_get_offset(sfep) < offset)
+			return -EFSCORRUPTED;
 
 		/* Check the inode number. */
 		ino = dops->sf_get_ino(sfp, sfep);
 		i8count += ino > XFS_DIR2_MAX_SHORT_INUM;
-		XFS_WANT_CORRUPTED_RETURN(mp, !xfs_dir_ino_validate(mp, ino));
+		error = xfs_dir_ino_validate(mp, ino);
+		if (error)
+			return error;
 
 		/* Check the file type. */
 		filetype = dops->sf_get_ftype(sfep);
-		XFS_WANT_CORRUPTED_RETURN(mp, filetype < XFS_DIR3_FT_MAX);
+		if (filetype >= XFS_DIR3_FT_MAX)
+			return -EFSCORRUPTED;
 
 		offset = xfs_dir2_sf_get_offset(sfep) +
 				dops->data_entsize(sfep->namelen);
 
 		sfep = next_sfep;
 	}
-	XFS_WANT_CORRUPTED_RETURN(mp, i8count == sfp->i8count);
-	XFS_WANT_CORRUPTED_RETURN(mp, (void *)sfep == (void *)endp);
+	if (i8count != sfp->i8count)
+		return -EFSCORRUPTED;
+	if ((void *)sfep != (void *)endp)
+		return -EFSCORRUPTED;
 
 	/* Make sure this whole thing ought to be in local format. */
-	XFS_WANT_CORRUPTED_RETURN(mp, offset +
-	       (sfp->count + 2) * (uint)sizeof(xfs_dir2_leaf_entry_t) +
-	       (uint)sizeof(xfs_dir2_block_tail_t) <= mp->m_dir_geo->blksize);
+	if (offset + (sfp->count + 2) * (uint)sizeof(xfs_dir2_leaf_entry_t) +
+	    (uint)sizeof(xfs_dir2_block_tail_t) > mp->m_dir_geo->blksize)
+		return -EFSCORRUPTED;
 
 	return 0;
 }

fs/xfs/libxfs/xfs_inode_fork.c

···
 	if (error)
 		return error;
 
+	/* Check inline dir contents. */
+	if (S_ISDIR(VFS_I(ip)->i_mode) &&
+	    dip->di_format == XFS_DINODE_FMT_LOCAL) {
+		error = xfs_dir2_sf_verify(ip);
+		if (error) {
+			xfs_idestroy_fork(ip, XFS_DATA_FORK);
+			return error;
+		}
+	}
+
 	if (xfs_is_reflink_inode(ip)) {
 		ASSERT(ip->i_cowfp == NULL);
 		xfs_ifork_init_cow(ip);
···
 	int		whichfork,
 	int		size)
 {
-	int		error;
-
 	/*
 	 * If the size is unreasonable, then something
 	 * is wrong and we just bail out rather than crash in
···
 		XFS_CORRUPTION_ERROR("xfs_iformat_local", XFS_ERRLEVEL_LOW,
 				     ip->i_mount, dip);
 		return -EFSCORRUPTED;
-	}
-
-	if (S_ISDIR(VFS_I(ip)->i_mode) && whichfork == XFS_DATA_FORK) {
-		error = xfs_dir2_sf_verify(ip->i_mount,
-				(struct xfs_dir2_sf_hdr *)XFS_DFORK_DPTR(dip),
-				size);
-		if (error)
-			return error;
 	}
 
 	xfs_init_local_fork(ip, whichfork, XFS_DFORK_PTR(dip, whichfork), size);
···
  * In these cases, the format always takes precedence, because the
  * format indicates the current state of the fork.
  */
-int
+void
 xfs_iflush_fork(
 	xfs_inode_t		*ip,
 	xfs_dinode_t		*dip,
···
 	char			*cp;
 	xfs_ifork_t		*ifp;
 	xfs_mount_t		*mp;
-	int			error;
 	static const short	brootflag[2] =
 		{ XFS_ILOG_DBROOT, XFS_ILOG_ABROOT };
 	static const short	dataflag[2] =
···
 		{ XFS_ILOG_DEXT, XFS_ILOG_AEXT };
 
 	if (!iip)
-		return 0;
+		return;
 	ifp = XFS_IFORK_PTR(ip, whichfork);
 	/*
 	 * This can happen if we gave up in iformat in an error path,
···
 	 */
 	if (!ifp) {
 		ASSERT(whichfork == XFS_ATTR_FORK);
-		return 0;
+		return;
 	}
 	cp = XFS_DFORK_PTR(dip, whichfork);
 	mp = ip->i_mount;
 	switch (XFS_IFORK_FORMAT(ip, whichfork)) {
 	case XFS_DINODE_FMT_LOCAL:
-		if (S_ISDIR(VFS_I(ip)->i_mode) && whichfork == XFS_DATA_FORK) {
-			error = xfs_dir2_sf_verify(mp,
-					(struct xfs_dir2_sf_hdr *)ifp->if_u1.if_data,
-					ifp->if_bytes);
-			if (error)
-				return error;
-		}
 		if ((iip->ili_fields & dataflag[whichfork]) &&
 		    (ifp->if_bytes > 0)) {
 			ASSERT(ifp->if_u1.if_data != NULL);
···
 		ASSERT(0);
 		break;
 	}
-	return 0;
 }
 
 /*

fs/xfs/libxfs/xfs_inode_fork.h

···
 struct xfs_ifork *xfs_iext_state_to_fork(struct xfs_inode *ip, int state);
 
 int		xfs_iformat_fork(struct xfs_inode *, struct xfs_dinode *);
-int		xfs_iflush_fork(struct xfs_inode *, struct xfs_dinode *,
+void		xfs_iflush_fork(struct xfs_inode *, struct xfs_dinode *,
 				struct xfs_inode_log_item *, int);
 void		xfs_idestroy_fork(struct xfs_inode *, int);
 void		xfs_idata_realloc(struct xfs_inode *, int, int);

fs/xfs/xfs_bmap_util.c

···
 	/*
 	 * Now that we've unmap all full blocks we'll have to zero out any
 	 * partial block at the beginning and/or end.  xfs_zero_range is
-	 * smart enough to skip any holes, including those we just created.
+	 * smart enough to skip any holes, including those we just created,
+	 * but we must take care not to zero beyond EOF and enlarge i_size.
 	 */
+
+	if (offset >= XFS_ISIZE(ip))
+		return 0;
+
+	if (offset + len > XFS_ISIZE(ip))
+		len = XFS_ISIZE(ip) - offset;
+
 	return xfs_zero_range(ip, offset, len, NULL);
 }
 

fs/xfs/xfs_inode.c

···
 #include "xfs_log.h"
 #include "xfs_bmap_btree.h"
 #include "xfs_reflink.h"
+#include "xfs_dir2_priv.h"
 
 kmem_zone_t *xfs_inode_zone;
 
···
 	struct xfs_inode_log_item *iip = ip->i_itemp;
 	struct xfs_dinode	*dip;
 	struct xfs_mount	*mp = ip->i_mount;
-	int			error;
 
 	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_ILOCK_SHARED));
 	ASSERT(xfs_isiflocked(ip));
···
 	if (ip->i_d.di_version < 3)
 		ip->i_d.di_flushiter++;
 
+	/* Check the inline directory data. */
+	if (S_ISDIR(VFS_I(ip)->i_mode) &&
+	    ip->i_d.di_format == XFS_DINODE_FMT_LOCAL &&
+	    xfs_dir2_sf_verify(ip))
+		goto corrupt_out;
+
 	/*
 	 * Copy the dirty parts of the inode into the on-disk inode.  We always
 	 * copy out the core of the inode, because if the inode is dirty at all
···
 	if (ip->i_d.di_flushiter == DI_MAX_FLUSH)
 		ip->i_d.di_flushiter = 0;
 
-	error = xfs_iflush_fork(ip, dip, iip, XFS_DATA_FORK);
-	if (error)
-		return error;
-	if (XFS_IFORK_Q(ip)) {
-		error = xfs_iflush_fork(ip, dip, iip, XFS_ATTR_FORK);
-		if (error)
-			return error;
-	}
+	xfs_iflush_fork(ip, dip, iip, XFS_DATA_FORK);
+	if (XFS_IFORK_Q(ip))
+		xfs_iflush_fork(ip, dip, iip, XFS_ATTR_FORK);
 	xfs_inobp_check(mp, bp);
 
 	/*

fs/xfs/xfs_itable.c

···
 		return error;
 
 	bcount = MIN(left, (int)(PAGE_SIZE / sizeof(*buffer)));
-	buffer = kmem_alloc(bcount * sizeof(*buffer), KM_SLEEP);
+	buffer = kmem_zalloc(bcount * sizeof(*buffer), KM_SLEEP);
 	do {
 		struct xfs_inobt_rec_incore	r;
 		int				stat;