FAILED: patch "[PATCH] ksmbd: fix a mount write count leak in" failed to apply to 5.15-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 5.15-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-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 277627b431a0a6401635c416a21b2a0f77a77347
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025071424-payroll-posh-4e3e@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

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

From 277627b431a0a6401635c416a21b2a0f77a77347 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Sun, 6 Jul 2025 02:26:45 +0100
Subject: [PATCH] ksmbd: fix a mount write count leak in
 ksmbd_vfs_kern_path_locked()

If the call of ksmbd_vfs_lock_parent() fails, we drop the parent_path
references and return an error.  We need to drop the write access we
just got on parent_path->mnt before we drop the mount reference - callers
assume that ksmbd_vfs_kern_path_locked() returns with mount write
access grabbed if and only if it has returned 0.

Fixes: 864fb5d37163 ("ksmbd: fix possible deadlock in smb2_open")
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/smb/server/vfs.c b/fs/smb/server/vfs.c
index 0f3aad12e495..d3437f6644e3 100644
--- a/fs/smb/server/vfs.c
+++ b/fs/smb/server/vfs.c
@@ -1282,6 +1282,7 @@ int ksmbd_vfs_kern_path_locked(struct ksmbd_work *work, char *name,
 
 		err = ksmbd_vfs_lock_parent(parent_path->dentry, path->dentry);
 		if (err) {
+			mnt_drop_write(parent_path->mnt);
 			path_put(path);
 			path_put(parent_path);
 		}