Commit 58291a74 authored by Mickaël Salaün's avatar Mickaël Salaün Committed by David S. Miller
Browse files

bpf: Move check_uarg_tail_zero() upward 



The function check_uarg_tail_zero() may be useful for other part of the
code in the syscall.c file. Move this function at the beginning of the
file.

Signed-off-by: default avatarMickaël Salaün <mic@digikod.net>
Acked-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 7b83f520

kernel/bpf/syscall.c

+26 −26
Original line number Diff line number Diff line
@@ -48,6 +48,32 @@ static const struct bpf_map_ops * const bpf_map_types[] = { 
#undef BPF_MAP_TYPE

};



static int check_uarg_tail_zero(void __user *uaddr,

				size_t expected_size,

				size_t actual_size)

{

	unsigned char __user *addr;

	unsigned char __user *end;

	unsigned char val;

	int err;



	if (actual_size <= expected_size)

		return 0;



	addr = uaddr + expected_size;

	end  = uaddr + actual_size;



	for (; addr < end; addr++) {

		err = get_user(val, addr);

		if (err)

			return err;

		if (val)

			return -E2BIG;

	}



	return 0;

}



static struct bpf_map *find_and_alloc_map(union bpf_attr *attr)

{

	struct bpf_map *map;
@@ -1246,32 +1272,6 @@ static int bpf_map_get_fd_by_id(const union bpf_attr *attr) 
	return fd;

}



static int check_uarg_tail_zero(void __user *uaddr,

				size_t expected_size,

				size_t actual_size)

{

	unsigned char __user *addr;

	unsigned char __user *end;

	unsigned char val;

	int err;



	if (actual_size <= expected_size)

		return 0;



	addr = uaddr + expected_size;

	end  = uaddr + actual_size;



	for (; addr < end; addr++) {

		err = get_user(val, addr);

		if (err)

			return err;

		if (val)

			return -E2BIG;

	}



	return 0;

}



static int bpf_prog_get_info_by_fd(struct bpf_prog *prog,

				   const union bpf_attr *attr,

				   union bpf_attr __user *uattr)

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