On Sat, 4 Jul 2020, Chengguang Xu wrote:
> After commit fdc85222d58e ("kernfs: kvmalloc xattr value
> instead of kmalloc"), simple xattr entry is allocated with
> kvmalloc() instead of kmalloc(), so we should release it
> with kvfree() instead of kfree().
>
> Cc: stable@xxxxxxxxxxxxxxx # v5.7
> Cc: Daniel Xu <dxu@xxxxxxxxx>
> Cc: Chris Down <chris@xxxxxxxxxxxxxx>
> Cc: Andreas Dilger <adilger@xxxxxxxxx>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Cc: Tejun Heo <tj@xxxxxxxxxx>
> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
> Cc: Hugh Dickins <hughd@xxxxxxxxxx>
> Fixes: fdc85222d58e ("kernfs: kvmalloc xattr value instead of kmalloc")
> Signed-off-by: Chengguang Xu <cgxu519@xxxxxxxxxxxx>
Good catch, thank you:
Acked-by: Hugh Dickins <hughd@xxxxxxxxxx>
> ---
> v1->v2:
> - Fix freeing issue in simple_xattrs_free().
> - Change patch subject.
>
> include/linux/xattr.h | 3 ++-
> mm/shmem.c | 2 +-
> 2 files changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/include/linux/xattr.h b/include/linux/xattr.h
> index 47eaa34f8761..c5afaf8ca7a2 100644
> --- a/include/linux/xattr.h
> +++ b/include/linux/xattr.h
> @@ -15,6 +15,7 @@
> #include <linux/slab.h>
> #include <linux/types.h>
> #include <linux/spinlock.h>
> +#include <linux/mm.h>
> #include <uapi/linux/xattr.h>
>
> struct inode;
> @@ -94,7 +95,7 @@ static inline void simple_xattrs_free(struct simple_xattrs *xattrs)
>
> list_for_each_entry_safe(xattr, node, &xattrs->head, list) {
> kfree(xattr->name);
> - kfree(xattr);
> + kvfree(xattr);
> }
> }
>
> diff --git a/mm/shmem.c b/mm/shmem.c
> index a0dbe62f8042..b2abca3f7f33 100644
> --- a/mm/shmem.c
> +++ b/mm/shmem.c
> @@ -3178,7 +3178,7 @@ static int shmem_initxattrs(struct inode *inode,
> new_xattr->name = kmalloc(XATTR_SECURITY_PREFIX_LEN + len,
> GFP_KERNEL);
> if (!new_xattr->name) {
> - kfree(new_xattr);
> + kvfree(new_xattr);
> return -ENOMEM;
> }
>
> --
> 2.20.1
>
>
>
>
