From: Jeremy Allison <jra@samba.org>
Date: Fri, 27 Jan 2017 01:19:24 +0000 (-0800)
Subject: s3: VFS: Don't allow symlink, link or rename on already converted paths.
X-Git-Tag: samba-4.4.10~36
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=81231afc2f968582fb1998b227713b34e74d9a7f;p=thirdparty%2Fsamba.git

s3: VFS: Don't allow symlink, link or rename on already converted paths.

Snapshot paths are a read-only filesystem.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=12531

Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Uri Simchoni <uri@samba.org>

Autobuild-User(master): Jeremy Allison <jra@samba.org>
Autobuild-Date(master): Mon Jan 30 22:26:29 CET 2017 on sn-devel-144

(backported from commit 0e1deb77f2b310ad7e5dd784174207adacf1c981)
---

diff --git a/source3/modules/vfs_shadow_copy2.c b/source3/modules/vfs_shadow_copy2.c
index f773d4f98c2..1345ca24d45 100644
--- a/source3/modules/vfs_shadow_copy2.c
+++ b/source3/modules/vfs_shadow_copy2.c
@@ -903,15 +903,17 @@ static int shadow_copy2_rename(vfs_handle_struct *handle,
 {
 	time_t timestamp_src = 0;
 	time_t timestamp_dst = 0;
+	char *snappath_src = NULL;
+	char *snappath_dst = NULL;
 
-	if (!shadow_copy2_strip_snapshot(talloc_tos(), handle,
+	if (!shadow_copy2_strip_snapshot_internal(talloc_tos(), handle,
 					 smb_fname_src->base_name,
-					 &timestamp_src, NULL)) {
+					 &timestamp_src, NULL, &snappath_src)) {
 		return -1;
 	}
-	if (!shadow_copy2_strip_snapshot(talloc_tos(), handle,
+	if (!shadow_copy2_strip_snapshot_internal(talloc_tos(), handle,
 					 smb_fname_dst->base_name,
-					 &timestamp_dst, NULL)) {
+					 &timestamp_dst, NULL, &snappath_dst)) {
 		return -1;
 	}
 	if (timestamp_src != 0) {
@@ -922,6 +924,17 @@ static int shadow_copy2_rename(vfs_handle_struct *handle,
 		errno = EROFS;
 		return -1;
 	}
+	/*
+	 * Don't allow rename on already converted paths.
+	 */
+	if (snappath_src != NULL) {
+		errno = EXDEV;
+		return -1;
+	}
+	if (snappath_dst != NULL) {
+		errno = EROFS;
+		return -1;
+	}
 	return SMB_VFS_NEXT_RENAME(handle, smb_fname_src, smb_fname_dst);
 }
 
@@ -930,19 +943,28 @@ static int shadow_copy2_symlink(vfs_handle_struct *handle,
 {
 	time_t timestamp_old = 0;
 	time_t timestamp_new = 0;
+	char *snappath_old = NULL;
+	char *snappath_new = NULL;
 
-	if (!shadow_copy2_strip_snapshot(talloc_tos(), handle, oldname,
-					 &timestamp_old, NULL)) {
+	if (!shadow_copy2_strip_snapshot_internal(talloc_tos(), handle, oldname,
+					 &timestamp_old, NULL, &snappath_old)) {
 		return -1;
 	}
-	if (!shadow_copy2_strip_snapshot(talloc_tos(), handle, newname,
-					 &timestamp_new, NULL)) {
+	if (!shadow_copy2_strip_snapshot_internal(talloc_tos(), handle, newname,
+					 &timestamp_new, NULL, &snappath_new)) {
 		return -1;
 	}
 	if ((timestamp_old != 0) || (timestamp_new != 0)) {
 		errno = EROFS;
 		return -1;
 	}
+	/*
+	 * Don't allow symlinks on already converted paths.
+	 */
+	if ((snappath_old != NULL) || (snappath_new != NULL)) {
+		errno = EROFS;
+		return -1;
+	}
 	return SMB_VFS_NEXT_SYMLINK(handle, oldname, newname);
 }
 
@@ -951,19 +973,28 @@ static int shadow_copy2_link(vfs_handle_struct *handle,
 {
 	time_t timestamp_old = 0;
 	time_t timestamp_new = 0;
+	char *snappath_old = NULL;
+	char *snappath_new = NULL;
 
-	if (!shadow_copy2_strip_snapshot(talloc_tos(), handle, oldname,
-					 &timestamp_old, NULL)) {
+	if (!shadow_copy2_strip_snapshot_internal(talloc_tos(), handle, oldname,
+					 &timestamp_old, NULL, &snappath_old)) {
 		return -1;
 	}
-	if (!shadow_copy2_strip_snapshot(talloc_tos(), handle, newname,
-					 &timestamp_new, NULL)) {
+	if (!shadow_copy2_strip_snapshot_internal(talloc_tos(), handle, newname,
+					 &timestamp_new, NULL, &snappath_new)) {
 		return -1;
 	}
 	if ((timestamp_old != 0) || (timestamp_new != 0)) {
 		errno = EROFS;
 		return -1;
 	}
+	/*
+	 * Don't allow links on already converted paths.
+	 */
+	if ((snappath_old != NULL) || (snappath_new != NULL)) {
+		errno = EROFS;
+		return -1;
+	}
 	return SMB_VFS_NEXT_LINK(handle, oldname, newname);
 }