From: Roberto Sassu <roberto.sassu@xxxxxxxxxx> commit 36ce9d76b0a93bae799e27e4f5ac35478c676592 upstream. 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. Link: https://lkml.kernel.org/r/20230607161523.2876433-1-roberto.sassu@xxxxxxxxxxxxxxx Fixes: c3b1b1cbf002 ("ramfs: add support for "mode=" mount option") Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: David Howells <dhowells@xxxxxxxxxx> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/ramfs/inode.c | 2 +- include/linux/ramfs.h | 1 + mm/shmem.c | 2 +- 3 files changed, 3 insertions(+), 2 deletions(-) --- a/fs/ramfs/inode.c +++ b/fs/ramfs/inode.c @@ -278,7 +278,7 @@ int ramfs_init_fs_context(struct fs_cont 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); --- 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 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -4196,7 +4196,7 @@ static struct file_system_type shmem_fs_ .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, };
