Patch "fs: prepare for adding LSM blob to backing_file" has been added to the 7.0-stable tree

Patch "fs: prepare for adding LSM blob to backing_file" has been added to the 7.0-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    fs: prepare for adding LSM blob to backing_file

to the 7.0-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     fs-prepare-for-adding-lsm-blob-to-backing_file.patch
and it can be found in the queue-7.0 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


From 880bd496ec72a6dcb00cb70c430ef752ba242ae7 Mon Sep 17 00:00:00 2001
From: Amir Goldstein <amir73il@gmail.com>
Date: Mon, 30 Mar 2026 10:27:51 +0200
Subject: fs: prepare for adding LSM blob to backing_file

From: Amir Goldstein <amir73il@gmail.com>

commit 880bd496ec72a6dcb00cb70c430ef752ba242ae7 upstream.

In preparation to adding LSM blob to backing_file struct, factor out
helpers init_backing_file() and backing_file_free().

Cc: stable@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
Cc: linux-unionfs@vger.kernel.org
Cc: linux-erofs@lists.ozlabs.org
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
[PM: use the term "LSM blob", fix comment style to match file]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/file_table.c |   22 ++++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)

--- a/fs/file_table.c
+++ b/fs/file_table.c
@@ -66,6 +66,12 @@ void backing_file_set_user_path(struct f
 }
 EXPORT_SYMBOL_GPL(backing_file_set_user_path);
 
+static inline void backing_file_free(struct backing_file *ff)
+{
+	path_put(&ff->user_path);
+	kmem_cache_free(bfilp_cachep, ff);
+}
+
 static inline void file_free(struct file *f)
 {
 	security_file_free(f);
@@ -73,8 +79,7 @@ static inline void file_free(struct file
 		percpu_counter_dec(&nr_files);
 	put_cred(f->f_cred);
 	if (unlikely(f->f_mode & FMODE_BACKING)) {
-		path_put(backing_file_user_path(f));
-		kmem_cache_free(bfilp_cachep, backing_file(f));
+		backing_file_free(backing_file(f));
 	} else {
 		kmem_cache_free(filp_cachep, f);
 	}
@@ -283,6 +288,12 @@ struct file *alloc_empty_file_noaccount(
 	return f;
 }
 
+static int init_backing_file(struct backing_file *ff)
+{
+	memset(&ff->user_path, 0, sizeof(ff->user_path));
+	return 0;
+}
+
 /*
  * Variant of alloc_empty_file() that allocates a backing_file container
  * and doesn't check and modify nr_files.
@@ -305,7 +316,14 @@ struct file *alloc_empty_backing_file(in
 		return ERR_PTR(error);
 	}
 
+	/* The f_mode flags must be set before fput(). */
 	ff->file.f_mode |= FMODE_BACKING | FMODE_NOACCOUNT;
+	error = init_backing_file(ff);
+	if (unlikely(error)) {
+		fput(&ff->file);
+		return ERR_PTR(error);
+	}
+
 	return &ff->file;
 }
 EXPORT_SYMBOL_GPL(alloc_empty_backing_file);


Patches currently in stable-queue which might be from amir73il@gmail.com are

queue-7.0/fs-prepare-for-adding-lsm-blob-to-backing_file.patch
queue-7.0/selinux-fix-overlayfs-mmap-and-mprotect-access-checks.patch
queue-7.0/lsm-add-backing_file-lsm-hooks.patch