From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=91.218.175.11 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794411137; b=EP34Tsw9Z4Y7iu3aUNsf9llMSmW8I4CsvjPcG0bQj4gV4kKqpCHqMyXeLBnml3MmLVka 0atcmmpNX695PAn20jYBKPKXrntCwkpSlJSOIOmm7T5q+AY9pBQARrr4wiDQGeLGjsLQu 1ZSi22HjgVQTXWWcr8jHBS5HbJ/WgQaG8PakkDqjspujFE6MQymxc/5vpG6l8bDKk5PYv OJkiKmFVLcKktXR8HoUhqckHGq6h2i7cwOdjMMFiCfsefRH8PjozQ9d6bJsRjelTnNryz jACDcBG3dBcAGD5bWAaxIAT4HlmnkPOYasPLyY4v3rXfzDsICUjeQTvDPjaiYAgGFZA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794411137; h=DMARC-Filter:X-Envelope-To:DKIM-Signature:X-Envelope-To:Received: X-Mizu-Trace-ID:X-Migadu-Flow:Message-ID:Date:MIME-Version:User-Agent: Subject:To:Cc:References:Content-Language:From:In-Reply-To: Content-Type:Content-Transfer-Encoding; bh=3V+m0lHRYCGoAKQSowYBsC0G4rGRJb6ZqIoJs29bl7k=; b=4JVeOBba7xwFa5rXD/VqdeylpMuY5joIe2JPcWpyPiFV5/a7r0XmZULdIrApzt6BO87l NRuu+eYv0UKJm0Ukb1u/9Bmkam6RK85oNpzMbbZIjQhKNppQ8i6zlL1xmK7ervbavCyN9 iHzoWNaiT9z+RVg4HcZH0CTnvGSK+NvIyRIO7+26htQZ9gfk0uhY3Hs/Gw4JPtzfqrlcE 3gU5/gFjSUocT7rbcn7DM9oP2fEj4+//XZXkreZa1T9AkU26H69SP+YFgO7dluhibv2/U wIiVFMeV7cknvcmbIyZPgagTBRWQ6OQjWyKj3jJmHY51o06sp4USLHZkFSvAXTL3Q5A== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b="uy/BQTuH"; arc=none smtp.remote-ip=91.218.175.11 Received: from mta0.migadu.com (out-11.mta0.migadu.com [91.218.175.11]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B8ADC606A321 for ; Wed, 11 Nov 2026 15:32:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org B8ADC606A321 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux.dev header.i=@linux.dev header.a=rsa-sha256 header.s=key1 header.b=uy/BQTuH X-Envelope-To: bpf@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=kIVasq+kbRO5M1l3P8L45IfXEI+1KoQRMMmYUB4tDUA=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1794411134; v=1; x=1795015934; b=uy/BQTuH1p1ATdCj2A8VhzZehT9qYzVNonM57K+p4inGNTVaQXmtsBPYRVvzgSAHCZn9Qf4C gfVtHwbMv9QYaCCFTcMNN290d85usZMRWU4MacWAZ9/LLJFRU97vdQ0p3b+fq7FcKmTP/pmGuG5 lYZtmUmmXj+DAmK2Q0OUwJaE= X-Envelope-To: bpf@vger.kernel.org Received: by smtp.migadu.com with ESMTPS id 04a8524071039322; Wed, 11 Nov 2026 15:32:14 +0000 X-Mizu-Trace-ID: 04a8524071039322 X-Migadu-Flow: FLOW_OUT Message-ID: Date: Wed, 11 Nov 2026 23:32:10 +0800 X-Mailing-List: bpf@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH bpf-next 3/9] bpf: Add log support for iter link_create To: sashiko-reviews@lists.linux.dev, bpf@vger.kernel.org Cc: linux-trace-kernel@vger.kernel.org References: <20261109140816.5196-1-leon.hwang@linux.dev> <20261109140816.5196-4-leon.hwang@linux.dev> Content-Language: en-US From: Leon Hwang In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2026/11/9 22:22, sashiko-bot@kernel.org wrote: > Thank you for your contribution! Sashiko AI review found 1 potential > issue to consider: > - [Low] bpf: misattributed iter_info error log messages in > bpf_iter_link_attach() > -- > > commit d8f64c129a2738b81f1bf280ca7bbad040d70081 > Author: Leon Hwang > > bpf: Add log support for iter link_create > > This commit passes the verifier log to bpf_iter_link_attach() and logs > diagnostic messages when BPF_LINK_CREATE fails for iterator programs. > >> diff --git a/kernel/bpf/bpf_iter.c b/kernel/bpf/bpf_iter.c >> index f0b29a1709357..dfefa5579e033 100644 >> --- a/kernel/bpf/bpf_iter.c >> +++ b/kernel/bpf/bpf_iter.c > [ ... ] >> @@ -538,24 +539,36 @@ int bpf_iter_link_attach(const union bpf_attr *attr, bpfptr_t uattr, > [ ... ] >> if (!bpfptr_is_null(ulinfo)) { >> err = bpf_check_uarg_tail_zero(ulinfo, sizeof(linfo), >> linfo_len); >> - if (err) >> + if (err) { >> + bpf_log(log, "Invalid iter_info.\n"); >> return err; >> + } >> linfo_len = min_t(u32, linfo_len, sizeof(linfo)); >> - if (copy_from_bpfptr(&linfo, ulinfo, linfo_len)) >> + if (copy_from_bpfptr(&linfo, ulinfo, linfo_len)) { >> + bpf_log(log, "Invalid iter_info_len.\n"); >> return -EFAULT; >> + } >> } > > [Severity: Low] > Are the log messages for iter_info and iter_info_len swapped or > misattributed here? > > By the time copy_from_bpfptr() runs, linfo_len has already been clamped to > sizeof(linfo), so copy_from_bpfptr() only fails when reading from the > ulinfo pointer (attr->link_create.iter_info) faults, yet it logs "Invalid > iter_info_len.". Conversely, bpf_check_uarg_tail_zero() rejects linfo_len > values larger than PAGE_SIZE with -E2BIG without touching ulinfo, which > logs "Invalid iter_info.". > Sounds reasonable to me, will swap them in the next revision. Thanks, Leon