Commit 473d9734 authored Oct 05, 2017 by Martin KaFai Lau Committed by David S. Miller Oct 07, 2017

bpf: Change bpf_obj_name_cpy() to better ensure map's name is init by 0



During get_info_by_fd, the prog/map name is memcpy-ed.  It depends
on the prog->aux->name and map->name to be zero initialized.

bpf_prog_aux is easy to guarantee that aux->name is zero init.

The name in bpf_map may be harder to be guaranteed in the future when
new map type is added.

Hence, this patch makes bpf_obj_name_cpy() to always zero init
the prog/map name.

Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent f192970d

kernel/bpf/syscall.c

+2 −3

Original line number	Diff line number	Diff line
		@@ -322,6 +322,8 @@ static int bpf_obj_name_cpy(char dst, const char src)
		{
		const char *end = src + BPF_OBJ_NAME_LEN;

		memset(dst, 0, BPF_OBJ_NAME_LEN);

		/* Copy all isalnum() and '_' char */
		while (src < end && *src) {
		if (!isalnum(src) && src != '_')
		@@ -333,9 +335,6 @@ static int bpf_obj_name_cpy(char dst, const char src)
		if (src == end)
		return -EINVAL;

		/* '\0' terminates dst */
		*dst = 0;

		return 0;
		}

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