From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D423CC8D4 for ; Sat, 5 Aug 2023 19:59:03 +0000 (UTC) Received: from mail-lf1-x12f.google.com (mail-lf1-x12f.google.com [IPv6:2a00:1450:4864:20::12f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8F444FA for ; Sat, 5 Aug 2023 12:59:02 -0700 (PDT) Received: by mail-lf1-x12f.google.com with SMTP id 2adb3069b0e04-4fe0e34f498so5525791e87.2 for ; Sat, 05 Aug 2023 12:59:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1691265541; x=1691870341; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:date:from:from:to:cc:subject:date:message-id:reply-to; bh=wrmsO5kbeLCgoLNRUeCbTqmbonHAao1zR+4IiEZ1vbI=; b=Mv5M/toV1VKXj/5+2HzMWhaVwkqB016YU3SMyxDBLb/7CvxKmhKqyBCjgglqxbvDBK bHcnH82unHx5gRrbjOck3ockId/XzEWDnV4BXVBVtBo3R42wd+Jw13oz/dkmgNgsYFBz 7N0HQBOVs8RGNr9oYF2b/65MPrmBztCdgUYZz0XgAwYvvhnDsuJ20HR7EYyMUKVUqJfN yg7Mpw6X350Hoy4mhykgkSpSzwIbpp9rZni7XGT1InTPtdVDe7oq2gzqqvBv5S6iCrNk 9PzdpEGW65dvc/T7VfFo/JJxQVg4doVXMv9VlzGNGtUmP3MO6lys4jJNVksjwRP5DF7L VzVw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1691265541; x=1691870341; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:date:from:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=wrmsO5kbeLCgoLNRUeCbTqmbonHAao1zR+4IiEZ1vbI=; b=c0MPHVhi4NKI9NLQa9N3pqSzt/S8obfz6++Lfv6vO63k+JU13dP2X2C5DAsliBrZMZ hcddXZz3uap9KvCnNtS8f4TY5Byq+Xq+6FiSwa7DN4O9QUZ9SulBpZuCuZw9/u9MhK8Q eS0ym+uPoYCc8LzRLwr/LR/rs7rARpVvtf8mzuQAmen1cT5N5eyyZ4IO/fu+9H5gg2rx c261EffhJkgvoxrZ9BKfA9qaj+jzen+apZndR3GwBHPknMnwPoh9pjrXM7z25CJtW/Nh hU/vJPAfnZtn4wlU5Ck9O8vy6z/MHqDLRUXAQxRU4rDairIUNcMEIqo9KvJAe8LnJ0sL uNZA== X-Gm-Message-State: AOJu0Yz1e61uX8ZnXZW2Fj9jK0C39Qb/pxyNKe7o9TihEMm/Bdl4ZP1m fqqQQ5z41687KnPKvUQT8oQ= X-Google-Smtp-Source: AGHT+IHx71kv0J30EPJTJTxKfpdLFbpzoCPN84cgtduN3tP2KmDKEq32ngZBTY/9waQboxYB+O7x2g== X-Received: by 2002:a05:6512:20cc:b0:4f9:5d2a:e0f6 with SMTP id u12-20020a05651220cc00b004f95d2ae0f6mr3170538lfr.14.1691265540503; Sat, 05 Aug 2023 12:59:00 -0700 (PDT) Received: from krava ([83.240.60.134]) by smtp.gmail.com with ESMTPSA id g17-20020aa7c591000000b00522d742bc4bsm2984720edq.62.2023.08.05.12.58.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 05 Aug 2023 12:59:00 -0700 (PDT) From: Jiri Olsa X-Google-Original-From: Jiri Olsa Date: Sat, 5 Aug 2023 21:58:58 +0200 To: Yafang Shao Cc: ast@kernel.org, daniel@iogearbox.net, john.fastabend@gmail.com, andrii@kernel.org, martin.lau@linux.dev, song@kernel.org, yonghong.song@linux.dev, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, bpf@vger.kernel.org, Dan Carpenter Subject: Re: [PATCH v4 bpf-next 1/2] bpf: Fix uninitialized symbol in bpf_perf_link_fill_kprobe() Message-ID: References: <20230804105732.3768-1-laoar.shao@gmail.com> <20230804105732.3768-2-laoar.shao@gmail.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230804105732.3768-2-laoar.shao@gmail.com> X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,FREEMAIL_FROM, RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net On Fri, Aug 04, 2023 at 10:57:31AM +0000, Yafang Shao wrote: > The patch 1b715e1b0ec5: "bpf: Support ->fill_link_info for > perf_event" from Jul 9, 2023, leads to the following Smatch static > checker warning: > > kernel/bpf/syscall.c:3416 bpf_perf_link_fill_kprobe() > error: uninitialized symbol 'type'. > > That can happens when uname is NULL. So fix it by verifying the uname > when we really need to fill it. > > Fixes: 1b715e1b0ec5 ("bpf: Support ->fill_link_info for perf_event") > Reported-by: Dan Carpenter > Closes: https://lore.kernel.org/bpf/85697a7e-f897-4f74-8b43-82721bebc462@kili.mountain/ > Signed-off-by: Yafang Shao > Acked-by: Yonghong Song Acked-by: Jiri Olsa jirka > --- > kernel/bpf/syscall.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c > index 7f4e8c3..166390f 100644 > --- a/kernel/bpf/syscall.c > +++ b/kernel/bpf/syscall.c > @@ -3378,14 +3378,14 @@ static int bpf_perf_link_fill_common(const struct perf_event *event, > > if (!ulen ^ !uname) > return -EINVAL; > - if (!uname) > - return 0; > > err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf, > probe_offset, probe_addr); > if (err) > return err; > > + if (!uname) > + return 0; > if (buf) { > len = strlen(buf); > err = bpf_copy_to_user(uname, buf, ulen, len); > -- > 1.8.3.1 >