From b1041cab47260374f389de1e81dc9a4a3b2e4859 Mon Sep 17 00:00:00 2001 From: Jiri Olsa Date: Thu, 7 Sep 2023 22:06:51 +0200 Subject: [PATCH] bpf: Add override check to kprobe multi link attach commit 41bc46c12a8053a1b3279a379bd6b5e87b045b85 upstream. 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: 0dcac2725406 ("bpf: Add multi kprobe link") Signed-off-by: Jiri Olsa Signed-off-by: Andrii Nakryiko Reviewed-by: Alan Maguire Cc: stable@vger.kernel.org Link: https://lore.kernel.org/bpf/20230907200652.926951-1-jolsa@kernel.org Signed-off-by: Greg Kroah-Hartman --- kernel/trace/bpf_trace.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 9fc5db1..8c77c54 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2684,6 +2684,17 @@ static void symbols_swap_r(void *a, void *b, int size, const void *priv) } } +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; @@ -2761,6 +2772,11 @@ 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; -- 2.7.4