On Mon, Dec 11, 2023 at 07:28:41PM +0800, Hou Tao wrote:
> From: Hou Tao <houtao1@xxxxxxxxxx>
>
> An abnormally big cnt may also be assigned to kprobe_multi.cnt when
> attaching multiple kprobes. It will trigger the following warning in
> kvmalloc_node():
>
> if (unlikely(size > INT_MAX)) {
> WARN_ON_ONCE(!(flags & __GFP_NOWARN));
> return NULL;
> }
>
> Fix the warning by using __GFP_NOWARN when invoking kvmalloc_array() in
> bpf_kprobe_multi_link_attach().
>
> Fixes: 0dcac2725406 ("bpf: Add multi kprobe link")
> Signed-off-by: Hou Tao <houtao1@xxxxxxxxxx>
Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>
thanks,
jirka
> ---
> kernel/trace/bpf_trace.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
> index 07b9b5896d6c..64f200890c19 100644
> --- a/kernel/trace/bpf_trace.c
> +++ b/kernel/trace/bpf_trace.c
> @@ -2605,11 +2605,11 @@ static int copy_user_syms(struct user_syms *us, unsigned long __user *usyms, u32
> int err = -ENOMEM;
> unsigned int i;
>
> - syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL);
> + syms = kvmalloc_array(cnt, sizeof(*syms), GFP_KERNEL | __GFP_NOWARN);
> if (!syms)
> goto error;
>
> - buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL);
> + buf = kvmalloc_array(cnt, KSYM_NAME_LEN, GFP_KERNEL | __GFP_NOWARN);
> if (!buf)
> goto error;
>
> @@ -2972,13 +2972,13 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr
> return -EINVAL;
>
> size = cnt * sizeof(*addrs);
> - addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
> + addrs = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL | __GFP_NOWARN);
> if (!addrs)
> return -ENOMEM;
>
> ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies);
> if (ucookies) {
> - cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL);
> + cookies = kvmalloc_array(cnt, sizeof(*addrs), GFP_KERNEL | __GFP_NOWARN);
> if (!cookies) {
> err = -ENOMEM;
> goto error;
> --
> 2.29.2
>
