Re: [PATCH 2/2] Add SMB 2 support for getting and setting SACLs

[Steve French <smfrench@gmail.com>]

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Lightly updated the patch to shrink patch2 by naming a variable the
same in patch 1, to avoid a rename of a local variable in patch2.  And
fixed one trivial checkpatch warning, and a trivial rebase issue.

Tentatively merged into cifs-2.6.git for-next pending more review(s)
and also the usual regression testing.

On Thu, Dec 17, 2020 at 3:00 PM Boris Protopopov <pboris@amazon.com> wrote:
>
> Fix passing of the additional security info via version
> operations. Force new open when getting SACL and avoid
> reuse of files that were previously open without
> sufficient privileges to access SACLs.
>
> Signed-off-by: Boris Protopopov <pboris@amazon.com>
> ---
>
> After further testing, I found that the security info was not being
> passed correctly to opts->get_acl and opts->get_acl_by_fid(). Also,
> it turned out that files open for read were being used to fetch
> SACL without proper privileges. This patch fixes these issues, and
> is meant to be squashed (comments dropped) with the earlier patch.
>
> fs/cifs/cifsacl.c | 10 +++++-----
>  fs/cifs/smb2ops.c |  4 ++--
>  fs/cifs/smb2pdu.c |  4 +++-
>  fs/cifs/xattr.c   | 10 ++++------
>  4 files changed, 14 insertions(+), 14 deletions(-)
>
> diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c
> index 353394d9ada8..6baa121952ce 100644
> --- a/fs/cifs/cifsacl.c
> +++ b/fs/cifs/cifsacl.c
> @@ -1245,7 +1245,7 @@ cifs_acl_to_fattr(struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
>         int rc = 0;
>         struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);
>         struct smb_version_operations *ops;
> -       const u32 unused = 0;
> +       const u32 info = 0;
>
>         cifs_dbg(NOISY, "converting ACL to mode for %s\n", path);
>
> @@ -1255,9 +1255,9 @@ cifs_acl_to_fattr(struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
>         ops = tlink_tcon(tlink)->ses->server->ops;
>
>         if (pfid && (ops->get_acl_by_fid))
> -               pntsd = ops->get_acl_by_fid(cifs_sb, pfid, &acllen, unused);
> +               pntsd = ops->get_acl_by_fid(cifs_sb, pfid, &acllen, info);
>         else if (ops->get_acl)
> -               pntsd = ops->get_acl(cifs_sb, inode, path, &acllen, unused);
> +               pntsd = ops->get_acl(cifs_sb, inode, path, &acllen, info);
>         else {
>                 cifs_put_tlink(tlink);
>                 return -EOPNOTSUPP;
> @@ -1295,7 +1295,7 @@ id_mode_to_cifs_acl(struct inode *inode, const char *path, __u64 nmode,
>         struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);
>         struct smb_version_operations *ops;
>         bool mode_from_sid, id_from_sid;
> -       const u32 unused = 0;
> +       const u32 info = 0;
>
>         if (IS_ERR(tlink))
>                 return PTR_ERR(tlink);
> @@ -1311,7 +1311,7 @@ id_mode_to_cifs_acl(struct inode *inode, const char *path, __u64 nmode,
>                 return -EOPNOTSUPP;
>         }
>
> -       pntsd = ops->get_acl(cifs_sb, inode, path, &secdesclen, unused);
> +       pntsd = ops->get_acl(cifs_sb, inode, path, &secdesclen, info);
>         if (IS_ERR(pntsd)) {
>                 rc = PTR_ERR(pntsd);
>                 cifs_dbg(VFS, "%s: error %d getting sec desc\n", __func__, rc);
> diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
> index d28a29728fb1..f5e198860c16 100644
> --- a/fs/cifs/smb2ops.c
> +++ b/fs/cifs/smb2ops.c
> @@ -3315,9 +3315,9 @@ get_smb2_acl(struct cifs_sb_info *cifs_sb,
>         struct cifs_ntsd *pntsd = NULL;
>         struct cifsFileInfo *open_file = NULL;
>
> -       if (inode)
> +       if (inode && !(info & SACL_SECINFO))
>                 open_file = find_readable_file(CIFS_I(inode), true);
> -       if (!open_file)
> +       if (!open_file || (info & SACL_SECINFO))
>                 return get_smb2_acl_by_path(cifs_sb, path, pacllen, info);
>
>         pntsd = get_smb2_acl_by_fid(cifs_sb, &open_file->fid, pacllen, info);
> diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
> index 0aeb63694306..b207e1eb6803 100644
> --- a/fs/cifs/smb2pdu.c
> +++ b/fs/cifs/smb2pdu.c
> @@ -3472,8 +3472,10 @@ SMB311_posix_query_info(const unsigned int xid, struct cifs_tcon *tcon,
>  int
>  SMB2_query_acl(const unsigned int xid, struct cifs_tcon *tcon,
>                u64 persistent_fid, u64 volatile_fid,
> -              void **data, u32 *plen, u32 additional_info)
> +              void **data, u32 *plen, u32 extra_info)
>  {
> +       __u32 additional_info = OWNER_SECINFO | GROUP_SECINFO | DACL_SECINFO |
> +                               extra_info;
>         *plen = 0;
>
>         return query_info(xid, tcon, persistent_fid, volatile_fid,
> diff --git a/fs/cifs/xattr.c b/fs/cifs/xattr.c
> index 9318a2acf4ee..6b658a1172ef 100644
> --- a/fs/cifs/xattr.c
> +++ b/fs/cifs/xattr.c
> @@ -340,21 +340,19 @@ static int cifs_xattr_get(const struct xattr_handler *handler,
>                  * fetch owner, DACL, and SACL if asked for full descriptor,
>                  * fetch owner and DACL otherwise
>                  */
> -               u32 acllen, additional_info = 0;
> +               u32 acllen, extra_info;
>                 struct cifs_ntsd *pacl;
>
>                 if (pTcon->ses->server->ops->get_acl == NULL)
>                         goto out; /* rc already EOPNOTSUPP */
>
>                 if (handler->flags == XATTR_CIFS_NTSD_FULL) {
> -                       additional_info = OWNER_SECINFO | GROUP_SECINFO |
> -                               DACL_SECINFO | SACL_SECINFO;
> +                       extra_info = SACL_SECINFO;
>                 } else {
> -                       additional_info = OWNER_SECINFO | GROUP_SECINFO |
> -                               DACL_SECINFO;
> +                       extra_info = 0;
>                 }
>                 pacl = pTcon->ses->server->ops->get_acl(cifs_sb,
> -                               inode, full_path, &acllen, additional_info);
> +                               inode, full_path, &acllen, extra_info);
>                 if (IS_ERR(pacl)) {
>                         rc = PTR_ERR(pacl);
>                         cifs_dbg(VFS, "%s: error %zd getting sec desc\n",
> --
> 2.18.4
>


-- 
Thanks,

Steve

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From d42d0c0334ef918310b11818c1805624c0ee9440 Mon Sep 17 00:00:00 2001
From: Boris Protopopov <pboris@amazon.com>
Date: Fri, 18 Dec 2020 11:30:12 -0600
Subject: [PATCH 1/2] SMB3: Add support for getting and setting SACLs

Add SYSTEM_SECURITY access flag and use with smb2 when opening
files for getting/setting SACLs. Add "system.cifs_ntsd_full"
extended attribute to allow user-space access to the functionality.
Avoid multiple server calls when setting owner, DACL, and SACL.

Signed-off-by: Boris Protopopov <pboris@amazon.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
---
 fs/cifs/cifsacl.c   | 15 ++++----
 fs/cifs/cifsglob.h  |  4 +--
 fs/cifs/cifspdu.h   |  2 ++
 fs/cifs/cifsproto.h |  4 +--
 fs/cifs/smb2ops.c   | 31 ++++++++++-------
 fs/cifs/smb2pdu.c   |  5 ++-
 fs/cifs/smb2proto.h |  4 +--
 fs/cifs/xattr.c     | 83 +++++++++++++++++++++++++++++++++------------
 8 files changed, 100 insertions(+), 48 deletions(-)

diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c
index 2f21f89871cc..2c9051f5e86a 100644
--- a/fs/cifs/cifsacl.c
+++ b/fs/cifs/cifsacl.c
@@ -1195,7 +1195,8 @@ static int build_sec_desc(struct cifs_ntsd *pntsd, struct cifs_ntsd *pnntsd,
 }
 
 struct cifs_ntsd *get_cifs_acl_by_fid(struct cifs_sb_info *cifs_sb,
-		const struct cifs_fid *cifsfid, u32 *pacllen)
+				      const struct cifs_fid *cifsfid, u32 *pacllen,
+				      u32 __maybe_unused unused)
 {
 	struct cifs_ntsd *pntsd = NULL;
 	unsigned int xid;
@@ -1263,7 +1264,7 @@ static struct cifs_ntsd *get_cifs_acl_by_path(struct cifs_sb_info *cifs_sb,
 /* Retrieve an ACL from the server */
 struct cifs_ntsd *get_cifs_acl(struct cifs_sb_info *cifs_sb,
 				      struct inode *inode, const char *path,
-				      u32 *pacllen)
+			       u32 *pacllen, u32 info)
 {
 	struct cifs_ntsd *pntsd = NULL;
 	struct cifsFileInfo *open_file = NULL;
@@ -1273,7 +1274,7 @@ struct cifs_ntsd *get_cifs_acl(struct cifs_sb_info *cifs_sb,
 	if (!open_file)
 		return get_cifs_acl_by_path(cifs_sb, path, pacllen);
 
-	pntsd = get_cifs_acl_by_fid(cifs_sb, &open_file->fid, pacllen);
+	pntsd = get_cifs_acl_by_fid(cifs_sb, &open_file->fid, pacllen, info);
 	cifsFileInfo_put(open_file);
 	return pntsd;
 }
@@ -1338,6 +1339,7 @@ cifs_acl_to_fattr(struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
 	int rc = 0;
 	struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);
 	struct smb_version_operations *ops;
+	const u32 info = 0;
 
 	cifs_dbg(NOISY, "converting ACL to mode for %s\n", path);
 
@@ -1347,9 +1349,9 @@ cifs_acl_to_fattr(struct cifs_sb_info *cifs_sb, struct cifs_fattr *fattr,
 	ops = tlink_tcon(tlink)->ses->server->ops;
 
 	if (pfid && (ops->get_acl_by_fid))
-		pntsd = ops->get_acl_by_fid(cifs_sb, pfid, &acllen);
+		pntsd = ops->get_acl_by_fid(cifs_sb, pfid, &acllen, info);
 	else if (ops->get_acl)
-		pntsd = ops->get_acl(cifs_sb, inode, path, &acllen);
+		pntsd = ops->get_acl(cifs_sb, inode, path, &acllen, info);
 	else {
 		cifs_put_tlink(tlink);
 		return -EOPNOTSUPP;
@@ -1388,6 +1390,7 @@ id_mode_to_cifs_acl(struct inode *inode, const char *path, __u64 *pnmode,
 	struct tcon_link *tlink = cifs_sb_tlink(cifs_sb);
 	struct smb_version_operations *ops;
 	bool mode_from_sid, id_from_sid;
+	const u32 info = 0;
 
 	if (IS_ERR(tlink))
 		return PTR_ERR(tlink);
@@ -1403,7 +1406,7 @@ id_mode_to_cifs_acl(struct inode *inode, const char *path, __u64 *pnmode,
 		return -EOPNOTSUPP;
 	}
 
-	pntsd = ops->get_acl(cifs_sb, inode, path, &secdesclen);
+	pntsd = ops->get_acl(cifs_sb, inode, path, &secdesclen, info);
 	if (IS_ERR(pntsd)) {
 		rc = PTR_ERR(pntsd);
 		cifs_dbg(VFS, "%s: error %d getting sec desc\n", __func__, rc);
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index 720d0f6a982d..50fcb65920e8 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -456,9 +456,9 @@ struct smb_version_operations {
 			const char *, const void *, const __u16,
 			const struct nls_table *, struct cifs_sb_info *);
 	struct cifs_ntsd * (*get_acl)(struct cifs_sb_info *, struct inode *,
-			const char *, u32 *);
+			const char *, u32 *, u32);
 	struct cifs_ntsd * (*get_acl_by_fid)(struct cifs_sb_info *,
-			const struct cifs_fid *, u32 *);
+			const struct cifs_fid *, u32 *, u32);
 	int (*set_acl)(struct cifs_ntsd *, __u32, struct inode *, const char *,
 			int);
 	/* writepages retry size */
diff --git a/fs/cifs/cifspdu.h b/fs/cifs/cifspdu.h
index ce51183ecaf4..64fe5a47b5e8 100644
--- a/fs/cifs/cifspdu.h
+++ b/fs/cifs/cifspdu.h
@@ -240,6 +240,8 @@
 #define SYNCHRONIZE           0x00100000  /* The file handle can waited on to */
 					  /* synchronize with the completion  */
 					  /* of an input/output request       */
+#define SYSTEM_SECURITY       0x01000000  /* The system access control list   */
+					  /* can be read and changed          */
 #define GENERIC_ALL           0x10000000
 #define GENERIC_EXECUTE       0x20000000
 #define GENERIC_WRITE         0x40000000
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index bd1c9b038568..340ff81ee87b 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -218,9 +218,9 @@ extern int cifs_acl_to_fattr(struct cifs_sb_info *cifs_sb,
 extern int id_mode_to_cifs_acl(struct inode *inode, const char *path, __u64 *pnmode,
 					kuid_t uid, kgid_t gid);
 extern struct cifs_ntsd *get_cifs_acl(struct cifs_sb_info *, struct inode *,
-					const char *, u32 *);
+				      const char *, u32 *, u32);
 extern struct cifs_ntsd *get_cifs_acl_by_fid(struct cifs_sb_info *,
-						const struct cifs_fid *, u32 *);
+				const struct cifs_fid *, u32 *, u32);
 extern int set_cifs_acl(struct cifs_ntsd *, __u32, struct inode *,
 				const char *, int);
 extern unsigned int setup_authusers_ACE(struct cifs_ace *pace);
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 949cd1177147..4a1761139e00 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -3214,7 +3214,7 @@ smb2_query_reparse_tag(const unsigned int xid, struct cifs_tcon *tcon,
 
 static struct cifs_ntsd *
 get_smb2_acl_by_fid(struct cifs_sb_info *cifs_sb,
-		const struct cifs_fid *cifsfid, u32 *pacllen)
+		    const struct cifs_fid *cifsfid, u32 *pacllen, u32 info)
 {
 	struct cifs_ntsd *pntsd = NULL;
 	unsigned int xid;
@@ -3228,7 +3228,8 @@ get_smb2_acl_by_fid(struct cifs_sb_info *cifs_sb,
 	cifs_dbg(FYI, "trying to get acl\n");
 
 	rc = SMB2_query_acl(xid, tlink_tcon(tlink), cifsfid->persistent_fid,
-			    cifsfid->volatile_fid, (void **)&pntsd, pacllen);
+			    cifsfid->volatile_fid, (void **)&pntsd, pacllen,
+			    info);
 	free_xid(xid);
 
 	cifs_put_tlink(tlink);
@@ -3242,7 +3243,7 @@ get_smb2_acl_by_fid(struct cifs_sb_info *cifs_sb,
 
 static struct cifs_ntsd *
 get_smb2_acl_by_path(struct cifs_sb_info *cifs_sb,
-		const char *path, u32 *pacllen)
+		     const char *path, u32 *pacllen, u32 info)
 {
 	struct cifs_ntsd *pntsd = NULL;
 	u8 oplock = SMB2_OPLOCK_LEVEL_NONE;
@@ -3280,12 +3281,16 @@ get_smb2_acl_by_path(struct cifs_sb_info *cifs_sb,
 	oparms.fid = &fid;
 	oparms.reconnect = false;
 
+	if (info & SACL_SECINFO)
+		oparms.desired_access |= SYSTEM_SECURITY;
+
 	rc = SMB2_open(xid, &oparms, utf16_path, &oplock, NULL, NULL, NULL,
 		       NULL);
 	kfree(utf16_path);
 	if (!rc) {
 		rc = SMB2_query_acl(xid, tlink_tcon(tlink), fid.persistent_fid,
-			    fid.volatile_fid, (void **)&pntsd, pacllen);
+				    fid.volatile_fid, (void **)&pntsd, pacllen,
+				    info);
 		SMB2_close(xid, tcon, fid.persistent_fid, fid.volatile_fid);
 	}
 
@@ -3319,10 +3324,12 @@ set_smb2_acl(struct cifs_ntsd *pnntsd, __u32 acllen,
 	tcon = tlink_tcon(tlink);
 	xid = get_xid();
 
-	if (aclflag == CIFS_ACL_OWNER || aclflag == CIFS_ACL_GROUP)
-		access_flags = WRITE_OWNER;
-	else
-		access_flags = WRITE_DAC;
+	if (aclflag & CIFS_ACL_OWNER || aclflag & CIFS_ACL_GROUP)
+		access_flags |= WRITE_OWNER;
+	if (aclflag & CIFS_ACL_SACL)
+		access_flags |= SYSTEM_SECURITY;
+	if (aclflag & CIFS_ACL_DACL)
+		access_flags |= WRITE_DAC;
 
 	utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
 	if (!utf16_path) {
@@ -3356,8 +3363,8 @@ set_smb2_acl(struct cifs_ntsd *pnntsd, __u32 acllen,
 /* Retrieve an ACL from the server */
 static struct cifs_ntsd *
 get_smb2_acl(struct cifs_sb_info *cifs_sb,
-				      struct inode *inode, const char *path,
-				      u32 *pacllen)
+	     struct inode *inode, const char *path,
+	     u32 *pacllen, u32 info)
 {
 	struct cifs_ntsd *pntsd = NULL;
 	struct cifsFileInfo *open_file = NULL;
@@ -3365,9 +3372,9 @@ get_smb2_acl(struct cifs_sb_info *cifs_sb,
 	if (inode)
 		open_file = find_readable_file(CIFS_I(inode), true);
 	if (!open_file)
-		return get_smb2_acl_by_path(cifs_sb, path, pacllen);
+		return get_smb2_acl_by_path(cifs_sb, path, pacllen, info);
 
-	pntsd = get_smb2_acl_by_fid(cifs_sb, &open_file->fid, pacllen);
+	pntsd = get_smb2_acl_by_fid(cifs_sb, &open_file->fid, pacllen, info);
 	cifsFileInfo_put(open_file);
 	return pntsd;
 }
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index fc06c762fbbf..202d8742d149 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -3479,10 +3479,9 @@ SMB311_posix_query_info(const unsigned int xid, struct cifs_tcon *tcon,
 
 int
 SMB2_query_acl(const unsigned int xid, struct cifs_tcon *tcon,
-		u64 persistent_fid, u64 volatile_fid,
-		void **data, u32 *plen)
+	       u64 persistent_fid, u64 volatile_fid,
+	       void **data, u32 *plen, u32 additional_info)
 {
-	__u32 additional_info = OWNER_SECINFO | GROUP_SECINFO | DACL_SECINFO;
 	*plen = 0;
 
 	return query_info(xid, tcon, persistent_fid, volatile_fid,
diff --git a/fs/cifs/smb2proto.h b/fs/cifs/smb2proto.h
index d4110447ee3a..9565e27681a5 100644
--- a/fs/cifs/smb2proto.h
+++ b/fs/cifs/smb2proto.h
@@ -200,8 +200,8 @@ extern int SMB2_query_info_init(struct cifs_tcon *tcon,
 				size_t input_len, void *input);
 extern void SMB2_query_info_free(struct smb_rqst *rqst);
 extern int SMB2_query_acl(const unsigned int xid, struct cifs_tcon *tcon,
-			   u64 persistent_file_id, u64 volatile_file_id,
-			   void **data, unsigned int *plen);
+			  u64 persistent_file_id, u64 volatile_file_id,
+			  void **data, unsigned int *plen, u32 info);
 extern int SMB2_get_srv_num(const unsigned int xid, struct cifs_tcon *tcon,
 			    u64 persistent_fid, u64 volatile_fid,
 			    __le64 *uniqueid);
diff --git a/fs/cifs/xattr.c b/fs/cifs/xattr.c
index b8299173ea7e..9318a2acf4ee 100644
--- a/fs/cifs/xattr.c
+++ b/fs/cifs/xattr.c
@@ -34,6 +34,7 @@
 #define MAX_EA_VALUE_SIZE CIFSMaxBufSize
 #define CIFS_XATTR_CIFS_ACL "system.cifs_acl" /* DACL only */
 #define CIFS_XATTR_CIFS_NTSD "system.cifs_ntsd" /* owner plus DACL */
+#define CIFS_XATTR_CIFS_NTSD_FULL "system.cifs_ntsd_full" /* owner/DACL/SACL */
 #define CIFS_XATTR_ATTRIB "cifs.dosattrib"  /* full name: user.cifs.dosattrib */
 #define CIFS_XATTR_CREATETIME "cifs.creationtime"  /* user.cifs.creationtime */
 /*
@@ -43,12 +44,13 @@
  */
 #define SMB3_XATTR_CIFS_ACL "system.smb3_acl" /* DACL only */
 #define SMB3_XATTR_CIFS_NTSD "system.smb3_ntsd" /* owner plus DACL */
+#define SMB3_XATTR_CIFS_NTSD_FULL "system.smb3_ntsd_full" /* owner/DACL/SACL */
 #define SMB3_XATTR_ATTRIB "smb3.dosattrib"  /* full name: user.smb3.dosattrib */
 #define SMB3_XATTR_CREATETIME "smb3.creationtime"  /* user.smb3.creationtime */
 /* BB need to add server (Samba e.g) support for security and trusted prefix */
 
 enum { XATTR_USER, XATTR_CIFS_ACL, XATTR_ACL_ACCESS, XATTR_ACL_DEFAULT,
-	XATTR_CIFS_NTSD };
+	XATTR_CIFS_NTSD, XATTR_CIFS_NTSD_FULL };
 
 static int cifs_attrib_set(unsigned int xid, struct cifs_tcon *pTcon,
 			   struct inode *inode, char *full_path,
@@ -164,7 +166,8 @@ static int cifs_xattr_set(const struct xattr_handler *handler,
 		break;
 
 	case XATTR_CIFS_ACL:
-	case XATTR_CIFS_NTSD: {
+	case XATTR_CIFS_NTSD:
+	case XATTR_CIFS_NTSD_FULL: {
 		struct cifs_ntsd *pacl;
 
 		if (!value)
@@ -174,23 +177,27 @@ static int cifs_xattr_set(const struct xattr_handler *handler,
 			rc = -ENOMEM;
 		} else {
 			memcpy(pacl, value, size);
-			if (value &&
-			    pTcon->ses->server->ops->set_acl) {
+			if (pTcon->ses->server->ops->set_acl) {
+				int aclflags = 0;
 				rc = 0;
-				if (handler->flags == XATTR_CIFS_NTSD) {
-					/* set owner and DACL */
-					rc = pTcon->ses->server->ops->set_acl(
-							pacl, size, inode,
-							full_path,
-							CIFS_ACL_OWNER);
-				}
-				if (rc == 0) {
-					/* set DACL */
-					rc = pTcon->ses->server->ops->set_acl(
-							pacl, size, inode,
-							full_path,
-							CIFS_ACL_DACL);
+
+				switch (handler->flags) {
+				case XATTR_CIFS_NTSD_FULL:
+					aclflags = (CIFS_ACL_OWNER |
+						    CIFS_ACL_DACL |
+						    CIFS_ACL_SACL);
+					break;
+				case XATTR_CIFS_NTSD:
+					aclflags = (CIFS_ACL_OWNER |
+						    CIFS_ACL_DACL);
+					break;
+				case XATTR_CIFS_ACL:
+				default:
+					aclflags = CIFS_ACL_DACL;
 				}
+
+				rc = pTcon->ses->server->ops->set_acl(pacl,
+					size, inode, full_path, aclflags);
 			} else {
 				rc = -EOPNOTSUPP;
 			}
@@ -327,16 +334,27 @@ static int cifs_xattr_get(const struct xattr_handler *handler,
 		break;
 
 	case XATTR_CIFS_ACL:
-	case XATTR_CIFS_NTSD: {
-		/* the whole ntsd is fetched regardless */
-		u32 acllen;
+	case XATTR_CIFS_NTSD:
+	case XATTR_CIFS_NTSD_FULL: {
+		/*
+		 * fetch owner, DACL, and SACL if asked for full descriptor,
+		 * fetch owner and DACL otherwise
+		 */
+		u32 acllen, additional_info = 0;
 		struct cifs_ntsd *pacl;
 
 		if (pTcon->ses->server->ops->get_acl == NULL)
 			goto out; /* rc already EOPNOTSUPP */
 
+		if (handler->flags == XATTR_CIFS_NTSD_FULL) {
+			additional_info = OWNER_SECINFO | GROUP_SECINFO |
+				DACL_SECINFO | SACL_SECINFO;
+		} else {
+			additional_info = OWNER_SECINFO | GROUP_SECINFO |
+				DACL_SECINFO;
+		}
 		pacl = pTcon->ses->server->ops->get_acl(cifs_sb,
-				inode, full_path, &acllen);
+				inode, full_path, &acllen, additional_info);
 		if (IS_ERR(pacl)) {
 			rc = PTR_ERR(pacl);
 			cifs_dbg(VFS, "%s: error %zd getting sec desc\n",
@@ -486,6 +504,27 @@ static const struct xattr_handler smb3_ntsd_xattr_handler = {
 	.set = cifs_xattr_set,
 };
 
+static const struct xattr_handler cifs_cifs_ntsd_full_xattr_handler = {
+	.name = CIFS_XATTR_CIFS_NTSD_FULL,
+	.flags = XATTR_CIFS_NTSD_FULL,
+	.get = cifs_xattr_get,
+	.set = cifs_xattr_set,
+};
+
+/*
+ * Although this is just an alias for the above, need to move away from
+ * confusing users and using the 20 year old term 'cifs' when it is no
+ * longer secure and was replaced by SMB2/SMB3 a long time ago, and
+ * SMB3 and later are highly secure.
+ */
+static const struct xattr_handler smb3_ntsd_full_xattr_handler = {
+	.name = SMB3_XATTR_CIFS_NTSD_FULL,
+	.flags = XATTR_CIFS_NTSD_FULL,
+	.get = cifs_xattr_get,
+	.set = cifs_xattr_set,
+};
+
+
 static const struct xattr_handler cifs_posix_acl_access_xattr_handler = {
 	.name = XATTR_NAME_POSIX_ACL_ACCESS,
 	.flags = XATTR_ACL_ACCESS,
@@ -507,6 +546,8 @@ const struct xattr_handler *cifs_xattr_handlers[] = {
 	&smb3_acl_xattr_handler, /* alias for above since avoiding "cifs" */
 	&cifs_cifs_ntsd_xattr_handler,
 	&smb3_ntsd_xattr_handler, /* alias for above since avoiding "cifs" */
+	&cifs_cifs_ntsd_full_xattr_handler,
+	&smb3_ntsd_full_xattr_handler, /* alias for above since avoiding "cifs" */
 	&cifs_posix_acl_access_xattr_handler,
 	&cifs_posix_acl_default_xattr_handler,
 	NULL
-- 
2.27.0


[-- Attachment #3: 0002-Add-SMB-2-support-for-getting-and-setting-SACLs.patch --]
[-- Type: text/x-patch, Size: 2967 bytes --]

From e1e3e35ae584c441606ae1c305dd377a84b7b51f Mon Sep 17 00:00:00 2001
From: Boris Protopopov <pboris@amazon.com>
Date: Thu, 17 Dec 2020 20:58:08 +0000
Subject: [PATCH 2/2] Add SMB 2 support for getting and setting SACLs

Fix passing of the additional security info via version
operations. Force new open when getting SACL and avoid
reuse of files that were previously open without
sufficient privileges to access SACLs.

Signed-off-by: Boris Protopopov <pboris@amazon.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
---
 fs/cifs/cifsacl.c | 10 +++++-----
 fs/cifs/smb2ops.c |  4 ++--
 fs/cifs/smb2pdu.c |  4 +++-
 fs/cifs/xattr.c   | 10 ++++------
 4 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 4a1761139e00..f19274857292 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -3369,9 +3369,9 @@ get_smb2_acl(struct cifs_sb_info *cifs_sb,
 	struct cifs_ntsd *pntsd = NULL;
 	struct cifsFileInfo *open_file = NULL;
 
-	if (inode)
+	if (inode && !(info & SACL_SECINFO))
 		open_file = find_readable_file(CIFS_I(inode), true);
-	if (!open_file)
+	if (!open_file || (info & SACL_SECINFO))
 		return get_smb2_acl_by_path(cifs_sb, path, pacllen, info);
 
 	pntsd = get_smb2_acl_by_fid(cifs_sb, &open_file->fid, pacllen, info);
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 202d8742d149..067eb44c7baa 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -3480,8 +3480,10 @@ SMB311_posix_query_info(const unsigned int xid, struct cifs_tcon *tcon,
 int
 SMB2_query_acl(const unsigned int xid, struct cifs_tcon *tcon,
 	       u64 persistent_fid, u64 volatile_fid,
-	       void **data, u32 *plen, u32 additional_info)
+	       void **data, u32 *plen, u32 extra_info)
 {
+	__u32 additional_info = OWNER_SECINFO | GROUP_SECINFO | DACL_SECINFO |
+				extra_info;
 	*plen = 0;
 
 	return query_info(xid, tcon, persistent_fid, volatile_fid,
diff --git a/fs/cifs/xattr.c b/fs/cifs/xattr.c
index 9318a2acf4ee..6b658a1172ef 100644
--- a/fs/cifs/xattr.c
+++ b/fs/cifs/xattr.c
@@ -340,21 +340,19 @@ static int cifs_xattr_get(const struct xattr_handler *handler,
 		 * fetch owner, DACL, and SACL if asked for full descriptor,
 		 * fetch owner and DACL otherwise
 		 */
-		u32 acllen, additional_info = 0;
+		u32 acllen, extra_info;
 		struct cifs_ntsd *pacl;
 
 		if (pTcon->ses->server->ops->get_acl == NULL)
 			goto out; /* rc already EOPNOTSUPP */
 
 		if (handler->flags == XATTR_CIFS_NTSD_FULL) {
-			additional_info = OWNER_SECINFO | GROUP_SECINFO |
-				DACL_SECINFO | SACL_SECINFO;
+			extra_info = SACL_SECINFO;
 		} else {
-			additional_info = OWNER_SECINFO | GROUP_SECINFO |
-				DACL_SECINFO;
+			extra_info = 0;
 		}
 		pacl = pTcon->ses->server->ops->get_acl(cifs_sb,
-				inode, full_path, &acllen, additional_info);
+				inode, full_path, &acllen, extra_info);
 		if (IS_ERR(pacl)) {
 			rc = PTR_ERR(pacl);
 			cifs_dbg(VFS, "%s: error %zd getting sec desc\n",
-- 
2.27.0