(cc's added)
On Wed, 7 Jun 2023 18:15:23 +0200 Roberto Sassu <roberto.sassu@xxxxxxxxxxxxxxx> wrote:
> From: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
>
> 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@xxxxxxxxxxxxxxx # 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@xxxxxxxxxx>
> ---
> 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
