linux-kernel - Re: [PATCH] bpf: fix a warning message in mark_ptr_not_null

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 16 Feb 2021 22:10:10 +0100
From:   KP Singh <kpsingh@...nel.org>
To:     Dan Carpenter <dan.carpenter@...cle.com>
Cc:     Alexei Starovoitov <ast@...nel.org>,
        Dmitrii Banshchikov <me@...que.spb.ru>,
        Daniel Borkmann <daniel@...earbox.net>,
        Andrii Nakryiko <andrii@...nel.org>,
        Martin KaFai Lau <kafai@...com>,
        Song Liu <songliubraving@...com>, Yonghong Song <yhs@...com>,
        John Fastabend <john.fastabend@...il.com>,
        bpf <bpf@...r.kernel.org>,
        open list <linux-kernel@...r.kernel.org>,
        kernel-janitors@...r.kernel.org
Subject: Re: [PATCH] bpf: fix a warning message in mark_ptr_not_null_reg()

On Tue, Feb 16, 2021 at 8:37 PM Dan Carpenter <dan.carpenter@...cle.com> wrote:
>
> The WARN_ON() argument is a condition, and it generates a stack trace
> but it doesn't print the warning.
>
> Fixes: 4ddb74165ae5 ("bpf: Extract nullable reg type conversion into a helper function")
> Signed-off-by: Dan Carpenter <dan.carpenter@...cle.com>
> ---
>  kernel/bpf/verifier.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
> index 056df6be3e30..bd4d1dfca73c 100644
> --- a/kernel/bpf/verifier.c
> +++ b/kernel/bpf/verifier.c
> @@ -1120,7 +1120,7 @@ static void mark_ptr_not_null_reg(struct bpf_reg_state *reg)
>                 reg->type = PTR_TO_RDWR_BUF;
>                 break;
>         default:
> -               WARN_ON("unknown nullable register type");
> +               WARN(1, "unknown nullable register type");

Should we use WARN_ONCE here? Also, I think the fix should be targeted
for bpf-next as
the patch that introduced this hasn't made it to bpf yet.

[...]