[SMB3][PATCH] smb3: do not attempt cifs operation in smb3 query info error path

[Steve French <smfrench@xxxxxxxxx>]

If backupuid mount option is sent, we can incorrectly retry
(on access denied on query info) with a cifs (FindFirst) operation
on an smb3 mount which causes the server to force the session close.

We set backup intent on open so no need for this fallback.

See kernel bugzilla 201435

Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
CC: Stable <stable@xxxxxxxxxxxxxxx>
---
 fs/cifs/inode.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 0945d40030eb..7483c09317b9 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -781,7 +781,15 @@ cifs_get_inode_info(struct inode **inode, const
char *full_path,
     } else if (rc == -EREMOTE) {
         cifs_create_dfs_fattr(&fattr, sb);
         rc = 0;
-    } else if (rc == -EACCES && backup_cred(cifs_sb)) {
+    } else if ((rc == -EACCES) && backup_cred(cifs_sb) &&
+           (strcmp(server->vals->version_string, SMB1_VERSION_STRING)
+              == 0)) {
+            /*
+             * For SMB2 and later the backup intent flag is already
+             * sent if needed on open and there is no path based
+             * FindFirst operation to use to retry with
+             */
+
             srchinf = kzalloc(sizeof(struct cifs_search_info),
                         GFP_KERNEL);
             if (srchinf == NULL) {

-- 
Thanks,

Steve

From 1fcb99e4c257f315de3c6805e6b75af4c044ddc8 Mon Sep 17 00:00:00 2001
From: Steve French <stfrench@xxxxxxxxxxxxx>
Date: Fri, 19 Oct 2018 00:45:21 -0500
Subject: [PATCH] smb3: do not attempt cifs operation in smb3 query info error
 path

If backupuid mount option is sent, we can incorrectly retry
(on access denied on query info) with a cifs (FindFirst) operation
on an smb3 mount which causes the server to force the session close.

We set backup intent on open so no need for this fallback.

See kernel bugzilla 201435

Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
CC: Stable <stable@xxxxxxxxxxxxxxx>
---
 fs/cifs/inode.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c
index 0945d40030eb..7483c09317b9 100644
--- a/fs/cifs/inode.c
+++ b/fs/cifs/inode.c
@@ -781,7 +781,15 @@ cifs_get_inode_info(struct inode **inode, const char *full_path,
 	} else if (rc == -EREMOTE) {
 		cifs_create_dfs_fattr(&fattr, sb);
 		rc = 0;
-	} else if (rc == -EACCES && backup_cred(cifs_sb)) {
+	} else if ((rc == -EACCES) && backup_cred(cifs_sb) &&
+		   (strcmp(server->vals->version_string, SMB1_VERSION_STRING)
+		      == 0)) {
+			/*
+			 * For SMB2 and later the backup intent flag is already
+			 * sent if needed on open and there is no path based
+			 * FindFirst operation to use to retry with
+			 */
+
 			srchinf = kzalloc(sizeof(struct cifs_search_info),
 						GFP_KERNEL);
 			if (srchinf == NULL) {
-- 
2.17.1