Commit 41bc46c1 authored by Jiri Olsa's avatar Jiri Olsa Committed by Andrii Nakryiko
Browse files

bpf: Add override check to kprobe multi link attach 



Currently the multi_kprobe link attach does not check error
injection list for programs with bpf_override_return helper
and allows them to attach anywhere. Adding the missing check.

Fixes: 0dcac272 ("bpf: Add multi kprobe link")
Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Reviewed-by: default avatarAlan Maguire <alan.maguire@oracle.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/bpf/20230907200652.926951-1-jolsa@kernel.org
parent ac28b1ec

kernel/trace/bpf_trace.c

+16 −0
Original line number Diff line number Diff line
@@ -2853,6 +2853,17 @@ static int get_modules_for_addrs(struct module ***mods, unsigned long *addrs, u3 
	return arr.mods_cnt;

}



static int addrs_check_error_injection_list(unsigned long *addrs, u32 cnt)

{

	u32 i;



	for (i = 0; i < cnt; i++) {

		if (!within_error_injection_list(addrs[i]))

			return -EINVAL;

	}

	return 0;

}



int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)

{

	struct bpf_kprobe_multi_link *link = NULL;
@@ -2930,6 +2941,11 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr 
			goto error;

	}



	if (prog->kprobe_override && addrs_check_error_injection_list(addrs, cnt)) {

		err = -EINVAL;

		goto error;

	}



	link = kzalloc(sizeof(*link), GFP_KERNEL);

	if (!link) {

		err = -ENOMEM;