From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 4B2FD2D5A0D for ; Thu, 10 Jul 2025 09:57:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752141479; cv=none; b=n5VAZqlJwPS7Ef+vm56xLfD4kXqkSQ9oPzfULbwOcVP2HPQmJwWk7CrQbNTJAmaOQyh3sZnXj37b88ggyg/HzRjg75hbBuFXnkUByDtyUlsm/A3RFexAUvj5fJ8DbmKN3gL44GqH8+BWHB8bzWC3S/9njsUC/HLUm8feY1ZAxvc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1752141479; c=relaxed/simple; bh=7xwliJkVJ22YY86sSCdm9ttnnURaGoeDVbNMIvocjHA=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=QpuQdFL8hc2asbrBLA2LsicvneMvFPU0DkifOFXz3OfQHrkI5fEaswaioO93nY27tsPwPTNKSCN3Dvmf2KeM5NI6Ppc5gxFk54PpdfRfhsEy8DR4bKXJPuurjeS/n5qBXIg8m4msPx2uBKuOSeg7HtoOKwJLfqvZeg0nxmaXNDY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=fZb2elh2; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="fZb2elh2" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1752141477; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=NDPcEVJCGuQNOn/llIxQqC/tDyrkofeBP4MHIQfFqcE=; b=fZb2elh2tGrKuB/y3s3uq3a5x8sJuX68LR97ZOei+MfVfMVoxYZaFQq5r4DxvX0n4g4Pq6 5vlB2ciYY4+NJIVe8Uy/CSacGrmOnPECbr0o5kyvtfph5cdG155a5S1uf9AV/74yfy0mR1 R0q/8z4DfkAmO/Vdn++Vni9bI+ypy6o= Received: from mail-wm1-f69.google.com (mail-wm1-f69.google.com [209.85.128.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-418-EFtV6O8yMOy-sYCqySt_Lg-1; Thu, 10 Jul 2025 05:57:53 -0400 X-MC-Unique: EFtV6O8yMOy-sYCqySt_Lg-1 X-Mimecast-MFC-AGG-ID: EFtV6O8yMOy-sYCqySt_Lg_1752141473 Received: by mail-wm1-f69.google.com with SMTP id 5b1f17b1804b1-45311704cdbso5317505e9.1 for ; Thu, 10 Jul 2025 02:57:53 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1752141472; x=1752746272; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=NDPcEVJCGuQNOn/llIxQqC/tDyrkofeBP4MHIQfFqcE=; b=p5FQcmj/svJONh0BOHiNQokbXP71ILZJ/0t0+Q+Bhpcuui3HMsGpSIL9zmZnyuv1Nr x0bDTjHVkRpnBPY4EKqP8COJLGaGJMWK3xW7owsDpt3I+FbrBtIbNW9STX0XRqy7zO0v kiYKzomd9MakKZyRqUFpl+CyHIVUnqguupAlzt2e0IPP0NbVPrUtwo6Oc82kj+STbGEi XAvDvdC/kCDT7q9Zxt3l7YW6NARnqBw51WJCwmdThmUqpSDHLj79wnHtKmp4kdhm8x99 8OaDOTWaHZqi301CdffDSA6Z3+wE8KM1+oTYOOn1T/2zOCGuslTiNg7QpRTBDOGZHLcX jsgA== X-Forwarded-Encrypted: i=1; AJvYcCX7x5+eYhaeS9u6Da/Qgs4JN2dZQp1OTbbweKzoNZtahr5TqL2IT7I3Pvwj90hEX7Gs0keu9bnx1xE/GVE=@vger.kernel.org X-Gm-Message-State: AOJu0YwV/PrurRJcn2DwQusDoxJMvnn6WNIc/2q8bSC6b+TjFsqCMfnR DzfOc0UwCur01kkh1hJ3Z0puHckpC9chUlJ3m11YrG1Qbkbv4MPbAVjxSza+YKFrKW4GKjsr5g4 iuUmt6Ll/SBPg34Z5HSGJVgevbSxMgcGM+paTx5DSWV67icjSFVe1CtA62H/hHAMFEw== X-Gm-Gg: ASbGncuhpFGhAclaLdwPGNd+p1OEOCDuyD1Qa3F+f/8IciHLtswNuX16tPbt4Q5/HHn /kNjdgFo+fCDq/sywEdiHyVO/Aoa8+MmBc/iVb0TcpH5/L99ESteVERdbnw/aCs3wRLFglScZ3z jNmwKUo01ET6b1+Ac60KA0MyUD9+WnKKoHOmtVICiD151Jz/YPqjAlDY6/MdcYKHfi+bC4XpDS4 JK76ML/SBdEcfPv8eMkHheqGEKCZdt/BSBdvegKjnyRq8vlYx3HOHEEaSO3mrQnw0ebwMyhHnfr BNkhsLl9H7SCqXg3wAMK6VoQjIGMYK5UBsyPELCvoqN7c0NA9XFr/W7lricYn+Qh2xj1vQ== X-Received: by 2002:a05:600c:4705:b0:453:59c2:e4f8 with SMTP id 5b1f17b1804b1-454dd1fbc3cmr18100375e9.1.1752141472571; Thu, 10 Jul 2025 02:57:52 -0700 (PDT) X-Google-Smtp-Source: AGHT+IFIJdl2it7UMshDGjV9veVJZFAmJkxwLppeIY5QkUEZVKY+WX/0RWzk+iU2OR29VnHls7guHw== X-Received: by 2002:a05:600c:4705:b0:453:59c2:e4f8 with SMTP id 5b1f17b1804b1-454dd1fbc3cmr18100095e9.1.1752141472067; Thu, 10 Jul 2025 02:57:52 -0700 (PDT) Received: from ?IPV6:2a0d:3344:271f:bc10:144e:d87a:be22:d005? ([2a0d:3344:271f:bc10:144e:d87a:be22:d005]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-3b5e8dc1ecbsm1422399f8f.25.2025.07.10.02.57.50 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 10 Jul 2025 02:57:51 -0700 (PDT) Message-ID: Date: Thu, 10 Jul 2025 11:57:50 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net v2] virtio-net: fix received length check in big packets To: Bui Quang Minh , netdev@vger.kernel.org Cc: "Michael S. Tsirkin" , Jason Wang , Xuan Zhuo , =?UTF-8?Q?Eugenio_P=C3=A9rez?= , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Gavin Li , Gavi Teitz , Parav Pandit , virtualization@lists.linux.dev, linux-kernel@vger.kernel.org References: <20250708144206.95091-1-minhquangbui99@gmail.com> Content-Language: en-US From: Paolo Abeni In-Reply-To: <20250708144206.95091-1-minhquangbui99@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 7/8/25 4:42 PM, Bui Quang Minh wrote: > Since commit 4959aebba8c0 ("virtio-net: use mtu size as buffer length > for big packets"), the allocated size for big packets is not > MAX_SKB_FRAGS * PAGE_SIZE anymore but depends on negotiated MTU. The > number of allocated frags for big packets is stored in > vi->big_packets_num_skbfrags. This commit fixes the received length > check corresponding to that change. The current incorrect check can lead > to NULL page pointer dereference in the below while loop when erroneous > length is received. > > Fixes: 4959aebba8c0 ("virtio-net: use mtu size as buffer length for big packets") > Signed-off-by: Bui Quang Minh > --- > Changes in v2: > - Remove incorrect give_pages call > --- > drivers/net/virtio_net.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index 5d674eb9a0f2..3a7f435c95ae 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -823,7 +823,7 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, > { > struct sk_buff *skb; > struct virtio_net_common_hdr *hdr; > - unsigned int copy, hdr_len, hdr_padded_len; > + unsigned int copy, hdr_len, hdr_padded_len, max_remaining_len; > struct page *page_to_free = NULL; > int tailroom, shinfo_size; > char *p, *hdr_p, *buf; > @@ -887,12 +887,15 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, > * tries to receive more than is possible. This is usually > * the case of a broken device. > */ > - if (unlikely(len > MAX_SKB_FRAGS * PAGE_SIZE)) { > + BUG_ON(offset >= PAGE_SIZE); Minor nit (not intended to block this patch): since you are touching this, you could consider replacing the BUG_ON() with a: if (WARN_ON_ONCE()) . /P