linux-kernel - [PATCH] shmem: Use ramfs_kill_sb() for kill

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20230607161523.2876433-1-roberto.sassu@huaweicloud.com>
Date:   Wed,  7 Jun 2023 18:15:23 +0200
From:   Roberto Sassu <roberto.sassu@...weicloud.com>
To:     hughd@...gle.com, akpm@...ux-foundation.org
Cc:     linux-kernel@...r.kernel.org,
        Roberto Sassu <roberto.sassu@...wei.com>,
        stable@...r.kernel.org
Subject: [PATCH] shmem: Use ramfs_kill_sb() for kill_sb method of ramfs-based tmpfs

From: Roberto Sassu <roberto.sassu@...wei.com>

As the ramfs-based tmpfs uses ramfs_init_fs_context() for the
init_fs_context method, which allocates fc->s_fs_info, use ramfs_kill_sb()
to free it and avoid a memory leak.

Cc: stable@...r.kernel.org # v5.4.x
Fixes: f32356261d44 ("vfs: Convert ramfs, shmem, tmpfs, devtmpfs, rootfs to use the new mount API")
Signed-off-by: Roberto Sassu <roberto.sassu@...wei.com>
---
 fs/ramfs/inode.c      | 2 +-
 include/linux/ramfs.h | 1 +
 mm/shmem.c            | 2 +-
 3 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/ramfs/inode.c b/fs/ramfs/inode.c
index 5ba580c7883..fef477c7810 100644
--- a/fs/ramfs/inode.c
+++ b/fs/ramfs/inode.c
@@ -278,7 +278,7 @@ int ramfs_init_fs_context(struct fs_context *fc)
 	return 0;
 }
 
-static void ramfs_kill_sb(struct super_block *sb)
+void ramfs_kill_sb(struct super_block *sb)
 {
 	kfree(sb->s_fs_info);
 	kill_litter_super(sb);
diff --git a/include/linux/ramfs.h b/include/linux/ramfs.h
index 917528d102c..d506dc63dd4 100644
--- a/include/linux/ramfs.h
+++ b/include/linux/ramfs.h
@@ -7,6 +7,7 @@
 struct inode *ramfs_get_inode(struct super_block *sb, const struct inode *dir,
 	 umode_t mode, dev_t dev);
 extern int ramfs_init_fs_context(struct fs_context *fc);
+extern void ramfs_kill_sb(struct super_block *sb);
 
 #ifdef CONFIG_MMU
 static inline int
diff --git a/mm/shmem.c b/mm/shmem.c
index e40a08c5c6d..74abb97ea55 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -4196,7 +4196,7 @@ static struct file_system_type shmem_fs_type = {
 	.name		= "tmpfs",
 	.init_fs_context = ramfs_init_fs_context,
 	.parameters	= ramfs_fs_parameters,
-	.kill_sb	= kill_litter_super,
+	.kill_sb	= ramfs_kill_sb,
 	.fs_flags	= FS_USERNS_MOUNT,
 };
 
-- 
2.25.1