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 <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/bpf/20230907200652.926951-1-jolsa@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 9fc5db1..8c77c54 100644 (file)
--- 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;