xfs: create structure verifier function for shortform xattrs (1e1bbd8e) · Commits · 戴 / test

fs/xfs/libxfs/xfs_attr_leaf.c

+74 −0

Original line number	Diff line number	Diff line
		@@ -872,6 +872,80 @@ xfs_attr_shortform_allfit(
		return xfs_attr_shortform_bytesfit(dp, bytes);
		}

		/* Verify the consistency of an inline attribute fork. */
		xfs_failaddr_t
		xfs_attr_shortform_verify(
		struct xfs_inode *ip)
		{
		struct xfs_attr_shortform *sfp;
		struct xfs_attr_sf_entry *sfep;
		struct xfs_attr_sf_entry *next_sfep;
		char *endp;
		struct xfs_ifork *ifp;
		int i;
		int size;

		ASSERT(ip->i_d.di_aformat == XFS_DINODE_FMT_LOCAL);
		ifp = XFS_IFORK_PTR(ip, XFS_ATTR_FORK);
		sfp = (struct xfs_attr_shortform *)ifp->if_u1.if_data;
		size = ifp->if_bytes;

		/*
		* Give up if the attribute is way too short.
		*/
		if (size < sizeof(struct xfs_attr_sf_hdr))
		return __this_address;

		endp = (char *)sfp + size;

		/* Check all reported entries */
		sfep = &sfp->list[0];
		for (i = 0; i < sfp->hdr.count; i++) {
		/*
		* struct xfs_attr_sf_entry has a variable length.
		* Check the fixed-offset parts of the structure are
		* within the data buffer.
		*/
		if (((char )sfep + sizeof(sfep)) >= endp)
		return __this_address;

		/* Don't allow names with known bad length. */
		if (sfep->namelen == 0)
		return __this_address;

		/*
		* Check that the variable-length part of the structure is
		* within the data buffer. The next entry starts after the
		* name component, so nextentry is an acceptable test.
		*/
		next_sfep = XFS_ATTR_SF_NEXTENTRY(sfep);
		if ((char *)next_sfep > endp)
		return __this_address;

		/*
		* Check for unknown flags. Short form doesn't support
		* the incomplete or local bits, so we can use the namespace
		* mask here.
		*/
		if (sfep->flags & ~XFS_ATTR_NSP_ONDISK_MASK)
		return __this_address;

		/*
		* Check for invalid namespace combinations. We only allow
		* 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)
		return __this_address;

		sfep = next_sfep;
		}
		if ((void )sfep != (void )endp)
		return __this_address;

		return NULL;
		}

		/*
		* Convert a leaf attribute list to shortform attribute list
		*/

fs/xfs/libxfs/xfs_attr_leaf.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -53,6 +53,7 @@ int xfs_attr_shortform_to_leaf(struct xfs_da_args *args,
		int xfs_attr_shortform_remove(struct xfs_da_args *args);
		int xfs_attr_shortform_allfit(struct xfs_buf bp, struct xfs_inode dp);
		int xfs_attr_shortform_bytesfit(struct xfs_inode *dp, int bytes);
		xfs_failaddr_t xfs_attr_shortform_verify(struct xfs_inode *ip);
		void xfs_attr_fork_remove(struct xfs_inode ip, struct xfs_trans tp);

		/*

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