X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/3e170ce000f1506b7b5d2c5c7faec85ceabb573d..5ba3f43ea354af8ad55bea84372a2bc834d8757c:/bsd/vfs/vfs_lookup.c?ds=sidebyside

diff --git a/bsd/vfs/vfs_lookup.c b/bsd/vfs/vfs_lookup.c
index 09bd470a9..55b86f9e6 100644
--- a/bsd/vfs/vfs_lookup.c
+++ b/bsd/vfs/vfs_lookup.c
@@ -182,6 +182,7 @@ namei(struct nameidata *ndp)
 #if CONFIG_VOLFS
 	int volfs_restarts = 0;
 #endif
+	size_t bytes_copied = 0;
 
 	fdp = p->p_fd;
 
@@ -244,10 +245,10 @@ vnode_recycled:
 retry_copy:
 	if (UIO_SEG_IS_USER_SPACE(ndp->ni_segflg)) {
 		error = copyinstr(ndp->ni_dirp, cnp->cn_pnbuf,
-			    cnp->cn_pnlen, (size_t *)&ndp->ni_pathlen);
+			    cnp->cn_pnlen, &bytes_copied);
 	} else {
 		error = copystr(CAST_DOWN(void *, ndp->ni_dirp), cnp->cn_pnbuf,
-			    cnp->cn_pnlen, (size_t *)&ndp->ni_pathlen);
+			    cnp->cn_pnlen, &bytes_copied);
 	}
 	if (error == ENAMETOOLONG && !(cnp->cn_flags & HASBUF)) {
 		MALLOC_ZONE(cnp->cn_pnbuf, caddr_t, MAXPATHLEN, M_NAMEI, M_WAITOK);
@@ -258,11 +259,14 @@ retry_copy:
 
 		cnp->cn_flags |= HASBUF;
 		cnp->cn_pnlen = MAXPATHLEN;
+		bytes_copied = 0;
 		
 		goto retry_copy;
 	}
 	if (error)
 	        goto error_out;
+	ndp->ni_pathlen = bytes_copied;
+	bytes_copied = 0;
 
 	/*
 	 * Since the name cache may contain positive entries of
@@ -366,6 +370,21 @@ retry_copy:
 	ndp->ni_vp  = NULLVP;
 
 	for (;;) {
+#if CONFIG_MACF
+		/*
+		 * Give MACF policies a chance to reject the lookup
+		 * before performing any filesystem operations.
+		 * This hook is called before resolving the path and
+		 * again each time a symlink is encountered.
+		 * NB: policies receive path information as supplied
+		 *     by the caller and thus cannot be trusted.
+		 */
+		error = mac_vnode_check_lookup_preflight(ctx, dp, cnp->cn_nameptr, cnp->cn_namelen);
+		if (error) {
+			goto error_out;
+		}
+#endif
+
 		ndp->ni_startdir = dp;
 
 		if ( (error = lookup(ndp)) ) {
@@ -458,6 +477,7 @@ namei_compound_available(vnode_t dp, struct nameidata *ndp)
 
 	return 0;
 }
+
 static int
 lookup_authorize_search(vnode_t dp, struct componentname *cnp, int dp_authorized_in_cache, vfs_context_t ctx)
 {
@@ -531,6 +551,7 @@ lookup_handle_rsrc_fork(vnode_t dp, struct nameidata *ndp, struct componentname
 {
 	vnode_t svp = NULLVP;
 	enum nsoperation nsop;
+	int nsflags;
 	int error;
 
 	if (dp->v_type != VREG) {
@@ -567,8 +588,13 @@ lookup_handle_rsrc_fork(vnode_t dp, struct nameidata *ndp, struct componentname
 			error = EPERM;
 			goto out;
 	}
+
+	nsflags = 0;
+	if (cnp->cn_flags & CN_RAW_ENCRYPTED)
+		nsflags |= NS_GETRAWENCRYPTED;
+
 	/* Ask the file system for the resource fork. */
-	error = vnode_getnamedstream(dp, &svp, XATTR_RESOURCEFORK_NAME, nsop, 0, ctx);
+	error = vnode_getnamedstream(dp, &svp, XATTR_RESOURCEFORK_NAME, nsop, nsflags, ctx);
 
 	/* During a create, it OK for stream vnode to be missing. */
 	if (error == ENOATTR || error == ENOENT) {
@@ -990,6 +1016,40 @@ dirloop:
 	 *    .. in the other file system.
 	 */
 	if ( (cnp->cn_flags & ISDOTDOT) ) {
+		/*
+		 * if this is a chroot'ed process, check if the current
+		 * directory is still a subdirectory of the process's
+		 * root directory.
+		 */
+		if (ndp->ni_rootdir && (ndp->ni_rootdir != rootvnode) &&
+		    dp !=  ndp->ni_rootdir) {
+			int sdir_error;
+			int is_subdir = FALSE;
+
+			sdir_error = vnode_issubdir(dp, ndp->ni_rootdir,
+			    &is_subdir, vfs_context_kernel());
+
+			/*
+			 * If we couldn't determine if dp is a subdirectory of
+			 * ndp->ni_rootdir (sdir_error != 0), we let the request
+			 * proceed.
+			 */
+			if (!sdir_error && !is_subdir) {
+				vnode_put(dp);
+				dp = ndp->ni_rootdir;
+				/*
+				 * There's a ref on the process's root directory
+				 * but we can't use vnode_getwithref here as
+				 * there is nothing preventing that ref being
+				 * released by another thread.
+				 */
+				if (vnode_get(dp)) {
+					error = ENOENT;
+					goto bad;
+				}
+			}
+		}
+
 		for (;;) {
 		        if (dp == ndp->ni_rootdir || dp == rootvnode) {
 			        ndp->ni_dvp = dp;
@@ -1419,7 +1479,14 @@ lookup_handle_symlink(struct nameidata *ndp, vnode_t *new_dp, vfs_context_t ctx)
 	int error;
 	char *cp;		/* pointer into pathname argument */
 	uio_t auio;
-	char uio_buf[ UIO_SIZEOF(1) ];
+	union {
+		union {
+			struct user_iovec s_uiovec;
+			struct kern_iovec s_kiovec;
+		} u_iovec;
+		struct uio s_uio;
+		char uio_buf[ UIO_SIZEOF(1) ];
+	} u_uio_buf; /* union only for aligning uio_buf correctly */
 	int need_newpathbuf;
 	u_int linklen;
 	struct componentname *cnp = &ndp->ni_cnd;
@@ -1446,7 +1513,8 @@ lookup_handle_symlink(struct nameidata *ndp, vnode_t *new_dp, vfs_context_t ctx)
 	} else {
 		cp = cnp->cn_pnbuf;
 	}
-	auio = uio_createwithbuffer(1, 0, UIO_SYSSPACE, UIO_READ, &uio_buf[0], sizeof(uio_buf));
+	auio = uio_createwithbuffer(1, 0, UIO_SYSSPACE, UIO_READ,
+	    &u_uio_buf.uio_buf[0], sizeof(u_uio_buf.uio_buf));
 
 	uio_addiov(auio, CAST_USER_ADDR_T(cp), MAXPATHLEN);
 
@@ -1695,7 +1763,7 @@ kdebug_lookup_gen_events(long *dbg_parms, int dbg_namelen, void *dp, boolean_t l
 	if (dbg_namelen <= (int)(3 * sizeof(long)))
 		code |= DBG_FUNC_END;
 
-	KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE, code, VM_KERNEL_ADDRPERM(dp), dbg_parms[0], dbg_parms[1], dbg_parms[2], 0);
+	KERNEL_DEBUG_CONSTANT_IST(KDEBUG_TRACE, code, kdebug_vnode(dp), dbg_parms[0], dbg_parms[1], dbg_parms[2], 0);
 
 	code &= ~DBG_FUNC_START;