From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pz2-f0.google.com (mail-pz2-f0.google.com [74.125.228.0]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3073CC8CE for ; Thu, 23 Jul 2026 17:15:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.228.0 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784826929; cv=none; b=Bbx44gcQXadSvzlAYOO2vqc71edROJMOA5p+W+SKHOp0x+eJaQVDIyEJsawIg1Ks+0yR4Pmov9R2GEliRuje1pDr6R0xEiARqTfhILJJ5rs20tNuWR7uXbROeDYE0l8RiTVwKcx+syyJvZYa+XxqskdqF45LWeUV1KfD+jXapuk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784826929; c=relaxed/simple; bh=gRvEv99Tveaj910OP+Pr72Hlm+AWoGqPbF8kIi4uYIk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=ifbgq+U1/5s5gDGR/EvMy3GzT3Vpi6/cPFY92QZe9jYLO0FoSc4l/bsVesiKvRDKjqtr6ZBLBrPhMDjbCA9XQe8+H34CdxDyvoA9/z9ZFDtTOSXxvvZYphbQ3dMBqCOxC0DSYSiSbj3AVt+xi2u8InZd7KXCxAUz5rb4gXO8lic= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=kXDM0YeA; arc=none smtp.client-ip=74.125.228.0 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="kXDM0YeA" Received: by mail-pz2-f0.google.com with SMTP id 41be03b00d2f7-cbb92a1213fso282295a12.0 for ; Thu, 23 Jul 2026 10:15:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1784826926; x=1785431726; darn=vger.kernel.org; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:from:to:cc:subject :date:message-id:reply-to:content-type; bh=qDOoFldaLflTi52Y4t0/f1yKLzKujtAjPwxewIEUekM=; b=kXDM0YeArlpWee1rz8t6MpObK07WYzNkhiMiwv9uvs0ZApUJG4xmdwpi4gYWouMJ8h OVlZE4DrrxOBuCx31rpfBoJXuB/mvE8Ksxlk9isQXetCwid2iqnuFPz3NO0M3e7LBNqp +jGs2ZstTOUAFyQUhvoxrL/k8qPxe/cJaw/9fV1gdA5wMieMAOoMFHWzqiX66I9Pcaod BsF/CZ8OhzZdy1kwvxDHRdxkqIXEzr94Ki8Q1SOzxcuQYhQS1hxFCwc9E5fghbjAzABY Hj5B67FHGi722J8r5Ci3CphbfLf8Zq3PQimtzKwQ4Vxt35tNjGrm/26LGKF57gt4DmWJ 4rZA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1784826926; x=1785431726; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=qDOoFldaLflTi52Y4t0/f1yKLzKujtAjPwxewIEUekM=; b=iQPt8KwTC07GRVAFuKY1HZij1vFN8raa/+6ZlAmrEdEqCxS1rf4yx7xPRKpv85kN9b 0ss65hMhRrlHLvQuNtYGboHB6zwtowp6GgtyNund6Lszm7WuCiFWtYM/uZFBl0t8lKvf JrhR15m72HAU5XFpDO1FlBrzapig1Tq7ERShiBLt9eUb/wCasTr9u37HTGJIyQdoSZ1D LUIBRhnqqEcNhqc9m07HJVaI3s6+KqIVgQCf2NPa6pXvyIc3QynwBWAdr+P2jYM1wKk1 BmAgxmZX9Q+dm2WizpOpllGJg/jQLIU4U6+ReuhTA08kPbrSQjDMieUInXnVTswzq0Sx G8qw== X-Forwarded-Encrypted: i=1; AHgh+RqFh4F0O+3hpdtQtf5FosKRXnpIM2bm36G+6aDwjD++Jze0GTuLKPEYnMESQLZX1EZ9HceDAkk=@vger.kernel.org X-Gm-Message-State: AOJu0YyKD8zwUTy3md+StsdScZaMNbgCvucVCS2xadPqNr6iogKl583/ uRihW7E8gYZNKnEesOnAO5HqG2ORlU3XYeK4m/MQ9Tn11a5RXxQ7tDp/ X-Gm-Gg: AR+sD13uCkF0poAb3Nqm6TwCV68qKEASM9/YjFDdLT/6PbdJySqrwPHpSgZaX+T0cmC +ppJ1xMnbp96VxCOFS7ZTWdO+8eCC2K+XLRGq3ljch2OBd23fTyT3jRpLLRVq6+OUzevSnDcK/H vOpNF0CLKeMWhi63j8hdfnSAveO+xCcyg3dAYed3yJLEyc85Fhk6L2b5un0wRnbdP3ANrije0Cq RpkyR1zHwsO/jFSupyF1g4ckV7kECIWFxAOdYbehA+xdYPjcHj87QuIcA2WYj3ern/qFmcGbqsO VsDI+aY/WvO8jfU3bDPuikClJPw3LpRjxlP00GedpkQoOcRLaBATKVp+tH7Fw5x1/99kKCDZQiI n5ajAkUyThqqy+huVWcrx0Lmflz4LVkXfj2/KSWPVqUnOrafNh+qthr61h+sATO2OrT3sV3U= X-Received: by 2002:a05:6a00:1f0b:b0:84e:23a:14ba with SMTP id d2e1a72fcca58-84e2bba3b90mr4535479b3a.55.1784826926412; Thu, 23 Jul 2026 10:15:26 -0700 (PDT) Received: from localhost ([2a03:2880:2ff:59::]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-84e1757833asm3453039b3a.29.2026.07.23.10.15.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 23 Jul 2026 10:15:25 -0700 (PDT) Date: Thu, 23 Jul 2026 10:15:15 -0700 From: Stanislav Fomichev To: Alexander Lobakin Cc: "Cen Zhang (Microsoft)" , magnus.karlsson@intel.com, maciej.fijalkowski@intel.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, sdf@fomichev.me, horms@kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, AutonomousCodeSecurity@microsoft.com, tgopinath@linux.microsoft.com, kys@microsoft.com Subject: Re: [PATCH net v2] xsk: reject undersized tx_metadata at runtime validation Message-ID: References: <20260722041326.75199-1-blbllhy@gmail.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: On 07/23, Alexander Lobakin wrote: > From: Stanislav Fomichev > Date: Wed, 22 Jul 2026 10:55:17 -0700 > > > On 07/22, Cen Zhang (Microsoft) wrote: > >> There is no metadata length check before accessing struct xsk_tx_metadata > >> fields in both xdp_umem_reg() (registration) and > >> xsk_buff_valid_tx_metadata() (runtime). Thus, an invalid small > >> tx_metadata_len (e.g. 8 bytes) passes registration and later causes an > >> out-of-bounds read when xsk_skb_metadata() accesses fields beyond the > >> declared metadata region. > > [...] > > > @@ -773,7 +773,7 @@ struct xdp_desc_ctx xp_raw_get_ctx(const struct xsk_buff_pool *pool, u64 addr) > > addr = __xp_raw_get_addr(pool, addr); > > > > ret.dma = __xp_raw_get_dma(pool, addr); > > - ret.meta = __xsk_buff_get_metadata(pool, __xp_raw_get_data(pool, addr)); > > + xsk_buff_read_metadata(pool, addr, &ret.meta); > > That effectively disables some micro-optimizations that were the reason > I created this helper -- __xp_raw_get_data() is inline, while > xsk_buff_read_metadata() uses the external version, probably some other > stuff (note the underscored __xsk_buff_get_metadata()) =\ This function > expanded to have no external calls on clang -O2, with this patch I'm not > sure it would. Any better ideas on how to solve it? I can convert all non libeth stuff to these new xsk_buff_read_metadata helpers and keep xp_raw_get_ctx to you? Will that work?