Subject: FAILED: patch "[PATCH] smb: client: clean up failed cached directory opens" failed to apply to 6.1-stable tree
To: zihanx@nebusec.ai,pc@manguebit.org,root@tr0jan.top,sorenson@redhat.com,vega@nebusec.ai
Cc: <stable@vger.kernel.org>
From: <gregkh@linuxfoundation.org>
Date: Tue, 29 Sep 2026 13:51:02 +0200
Message-ID: <2026092902-hacksaw-legwork-e770@gregkh>
Precedence: bulk
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The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x d2ff5fb93ea83034025850266b5eed391f96b825
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026092902-hacksaw-legwork-e770@gregkh' --subject-prefix 'PATCH 6.1.y' 'HEAD^..'

Possible dependencies:


thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From d2ff5fb93ea83034025850266b5eed391f96b825 Mon Sep 17 00:00:00 2001
From: Zihan Xi <zihanx@nebusec.ai>
Date: Wed, 16 Sep 2026 15:29:27 +0000
Subject: [PATCH] smb: client: clean up failed cached directory opens

open_cached_dir() sends CREATE and QUERY_INFO as a compound request. If
the CREATE succeeds but a later command returns an error, the function
must retain the CREATE FID so common cleanup can issue SMB2_close(). It
also must not treat a response error as a valid CREATE.

Validate the CREATE response before using its fields, record the FIDs, and
mark the handle open before handling errors from later compound commands.
Move the -EREMCHG reconnect handling before response validation so a
missing response does not hide the reconnect request. Count the handle
when it is marked open; confirmed close responses decrement the counter,
while existing close retry behavior remains best effort on transport
failures.

Fixes: b0f6df737a1c ("cifs: cache FILE_ALL_INFO for the shared root handle")
Cc: stable@vger.kernel.org
Reported-by: Vega <vega@nebusec.ai>
Assisted-by: LLM
Co-developed-by: Luxing Yin <root@tr0jan.top>
Signed-off-by: Luxing Yin <root@tr0jan.top>
Signed-off-by: Zihan Xi <zihanx@nebusec.ai>
Tested-by: Frank Sorenson <sorenson@redhat.com>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>

diff --git a/fs/smb/client/cached_dir.c b/fs/smb/client/cached_dir.c
index 88d5e9a32f28..647fa26da4d2 100644
--- a/fs/smb/client/cached_dir.c
+++ b/fs/smb/client/cached_dir.c
@@ -8,6 +8,7 @@
 #include <linux/namei.h>
 #include "cifsglob.h"
 #include "cifsproto.h"
+#include "../common/smb2status.h"
 #include "cifs_debug.h"
 #include "smb2proto.h"
 #include "cached_dir.h"
@@ -323,25 +324,37 @@ replay_again:
 	rc = compound_send_recv(xid, ses, server,
 				flags, 2, rqst,
 				resp_buftype, rsp_iov);
-	if (rc) {
-		if (rc == -EREMCHG) {
-			tcon->need_reconnect = true;
-			pr_warn_once("server share %s deleted\n",
-				     tcon->tree_name);
-		}
+	if (rc == -EREMCHG) {
+		tcon->need_reconnect = true;
+		pr_warn_once("server share %s deleted\n",
+			     tcon->tree_name);
+	}
+
+	if (!rsp_iov[0].iov_base || rsp_iov[0].iov_len < sizeof(*o_rsp)) {
+		if (!rc)
+			rc = -EIO;
 		goto oshr_free;
 	}
-	cfid->is_open = true;
-
-	spin_lock(&cfids->cfid_list_lock);
 
 	o_rsp = (struct smb2_create_rsp *)rsp_iov[0].iov_base;
+	if (o_rsp->hdr.Status != STATUS_SUCCESS) {
+		if (!rc)
+			rc = -EIO;
+		goto oshr_free;
+	}
+
 	oparms.fid->persistent_fid = o_rsp->PersistentFileId;
 	oparms.fid->volatile_fid = o_rsp->VolatileFileId;
 #ifdef CONFIG_CIFS_DEBUG2
 	oparms.fid->mid = le64_to_cpu(o_rsp->hdr.MessageId);
 #endif /* CIFS_DEBUG2 */
+	cfid->is_open = true;
+	atomic_inc(&tcon->num_remote_opens);
 
+	if (rc)
+		goto oshr_free;
+
+	spin_lock(&cfids->cfid_list_lock);
 
 	if (o_rsp->OplockLevel != SMB2_OPLOCK_LEVEL_LEASE) {
 		spin_unlock(&cfids->cfid_list_lock);
@@ -408,7 +421,6 @@ out:
 		close_cached_dir(cfid);
 	} else {
 		*ret_cfid = cfid;
-		atomic_inc(&tcon->num_remote_opens);
 	}
 	kfree(utf16_path);