From: Jeremy Allison <jra@samba.org>
Date: Mon, 1 Aug 2022 21:24:31 +0000 (-0700)
Subject: s3: smbd: In filename_convert_dirfsp_nosymlink(), in SMB1-only POSIX mode, allow... 
X-Git-Tag: samba-4.17.0rc1~151
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=5249cb3d0fdfe96c4bc65a6338d798feada590ec;p=thirdparty%2Fsamba.git

s3: smbd: In filename_convert_dirfsp_nosymlink(), in SMB1-only POSIX mode, allow a pathname referencing a symlink to be returned.

Doesn't contain a valid smb_fname->fsp pointer of course,
and is only used by the SMB1 code to take a reference to
a smylink name for manipulation (unlinkat, readlinkat etc.).

Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Volker Lendecke <vl@samba.org>
---

diff --git a/source3/smbd/filename.c b/source3/smbd/filename.c
index 27650326ade..a9a998db7c5 100644
--- a/source3/smbd/filename.c
+++ b/source3/smbd/filename.c
@@ -2907,6 +2907,28 @@ static NTSTATUS filename_convert_dirfsp_nosymlink(
 		char *normalized = NULL;
 
 		if (VALID_STAT(smb_fname_rel->st)) {
+#if defined(WITH_SMB1SERVER)
+			/*
+			 * In SMB1 posix mode, if this is a symlink,
+			 * allow access to the name with a NULL smb_fname->fsp.
+			 */
+			if (!conn->sconn->using_smb2 &&
+					posix &&
+					S_ISLNK(smb_fname_rel->st.st_ex_mode)) {
+				SMB_ASSERT(smb_fname_rel->fsp == NULL);
+				SMB_ASSERT(streamname == NULL);
+
+				smb_fname = full_path_from_dirfsp_atname(
+						mem_ctx,
+						smb_dirname->fsp,
+						smb_fname_rel);
+				if (smb_fname == NULL) {
+					status = NT_STATUS_NO_MEMORY;
+					goto fail;
+				}
+				goto done;
+			}
+#endif
 			/*
 			 * NT_STATUS_OBJECT_NAME_NOT_FOUND is
 			 * misleading: The object exists but might be