From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8CB62C433EF for ; Sat, 23 Apr 2022 11:26:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235220AbiDWL3Q (ORCPT ); Sat, 23 Apr 2022 07:29:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38950 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234275AbiDWL3P (ORCPT ); Sat, 23 Apr 2022 07:29:15 -0400 Received: from mail-ej1-x633.google.com (mail-ej1-x633.google.com [IPv6:2a00:1450:4864:20::633]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9397D4B1FB for ; Sat, 23 Apr 2022 04:26:17 -0700 (PDT) Received: by mail-ej1-x633.google.com with SMTP id bv19so20920858ejb.6 for ; Sat, 23 Apr 2022 04:26:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=blackwall-org.20210112.gappssmtp.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=R55cctVnDSIYjYkatNLitr0ArQTcklMikj4+Ic6cAKg=; b=erJbMPNnIOT+22gFdm3LWgYV0fgA1wb7MgoBN5qxI0I0mvBsjKWTJw1UIXhhoZpGlj pQYdAwifQWxNJzJe9sJ9tD+s1nKOSNrFa8vyjHY1KebNaD/f2uu1oan/mMiQO5lb7cAG ouhGWKZ0fh8xnrRS84UHwovhspdXt513Ev2Dt5JJjPeT2IcSGSIEDz8tyZ6FffdrVmg7 J+PhyF1iUTe1lxu9bB4d2TULYnP93sLVRZswjytxxAuI+7XdYahOLEoIkgAFptx9zjUi ll5JUxYSzKeCrt1KUa/5/Bpo2UtN9Hh0YKyZaOEuV8QnuEbjJYRmkQ2zNLp8ahOr+n+G /2Ag== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=R55cctVnDSIYjYkatNLitr0ArQTcklMikj4+Ic6cAKg=; b=bznW9GOSsBw/nZgWgwEA/1p749UPlYPPQgwigH9s+XU7PnWMij3rQ3Nf2cWlacmJnE 6wehH/fVo7tu4Hp7Y8Mo6Yd8TuEQUGY2RWqYD4jB1ADYm3cARRjUlZ6ATQCIWW2X55iq P5LsGGjBh5sBhDWvIzcN4jSDCfr2yxF9pS6kzzntff64jmRz5Ny+ybo+RzUkI6to4t/0 HVM39q9U4p0SnRSV2rPwkW9FVUZ2mSW8Daouoqrc68K2mvr6nznBqgKVR2EKFOTRcbgN HnXuib6BzB1vGrkkKX6Wv17EknHymcAWYk52QQVcHhMp8WUm5F+cbZfBTbLzcZ9NexSz K/eA== X-Gm-Message-State: AOAM530C7Dz/6UqLHjfvYwKl7Y8+xL2M2FaobDe1DesDein17Tae8NMP x9uotJzBVirBUyd65UmUyNh6KJOvG13zL93G X-Google-Smtp-Source: ABdhPJwDSahCbjVD5h1/H5H7a0X0JfYBL9mDd6r+7XqDUQSVtRcVnjP5Tw1CJi2ljaUYgw0M90XH9Q== X-Received: by 2002:a17:907:720d:b0:6f0:fa7b:fca1 with SMTP id dr13-20020a170907720d00b006f0fa7bfca1mr7092405ejc.514.1650713175763; Sat, 23 Apr 2022 04:26:15 -0700 (PDT) Received: from debil.. (87-243-81-1.ip.btc-net.bg. [87.243.81.1]) by smtp.gmail.com with ESMTPSA id e19-20020a056402105300b004162d0b4cbbsm2077897edu.93.2022.04.23.04.26.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 23 Apr 2022 04:26:15 -0700 (PDT) From: Nikolay Aleksandrov To: netdev@vger.kernel.org Cc: kuba@kernel.org, davem@davemloft.net, Nikolay Aleksandrov , stable@vger.kernel.org, Jason Wang , Xuan Zhuo , Daniel Borkmann , "Michael S. Tsirkin" , virtualization@lists.linux-foundation.org Subject: [PATCH net] virtio_net: fix wrong buf address calculation when using xdp Date: Sat, 23 Apr 2022 14:26:12 +0300 Message-Id: <20220423112612.2292774-1-razor@blackwall.org> X-Mailer: git-send-email 2.35.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org We received a report[1] of kernel crashes when Cilium is used in XDP mode with virtio_net after updating to newer kernels. After investigating the reason it turned out that when using mergeable bufs with an XDP program which adjusts xdp.data or xdp.data_meta page_to_buf() calculates the build_skb address wrong because the offset can become less than the headroom so it gets the address of the previous page (-X bytes depending on how lower offset is): page_to_skb: page addr ffff9eb2923e2000 buf ffff9eb2923e1ffc offset 252 headroom 256 This is a pr_err() I added in the beginning of page_to_skb which clearly shows offset that is less than headroom by adding 4 bytes of metadata via an xdp prog. The calculations done are: receive_mergeable(): headroom = VIRTIO_XDP_HEADROOM; // VIRTIO_XDP_HEADROOM == 256 bytes offset = xdp.data - page_address(xdp_page) - vi->hdr_len - metasize; page_to_skb(): p = page_address(page) + offset; ... buf = p - headroom; Now buf goes -4 bytes from the page's starting address as can be seen above which is set as skb->head and skb->data by build_skb later. Depending on what's done with the skb (when it's freed most often) we get all kinds of corruptions and BUG_ON() triggers in mm[2]. The story of the faulty commit is interesting because the patch was sent and applied twice (it seems the first one got lost during merge back in 5.13 window). The first version of the patch that was applied as: commit 7bf64460e3b2 ("virtio-net: get build_skb() buf by data ptr") was actually correct because it calculated the page starting address without relying on offset or headroom, but then the second version that was applied as: commit 8fb7da9e9907 ("virtio_net: get build_skb() buf by data ptr") was wrong and added the above calculation. An example xdp prog[3] is below. [1] https://github.com/cilium/cilium/issues/19453 [2] Two of the many traces: [ 40.437400] BUG: Bad page state in process swapper/0 pfn:14940 [ 40.916726] BUG: Bad page state in process systemd-resolve pfn:053b7 [ 41.300891] kernel BUG at include/linux/mm.h:720! [ 41.301801] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI [ 41.302784] CPU: 1 PID: 1181 Comm: kubelet Kdump: loaded Tainted: G B W 5.18.0-rc1+ #37 [ 41.304458] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1.fc35 04/01/2014 [ 41.306018] RIP: 0010:page_frag_free+0x79/0xe0 [ 41.306836] Code: 00 00 75 ea 48 8b 07 a9 00 00 01 00 74 e0 48 8b 47 48 48 8d 50 ff a8 01 48 0f 45 fa eb d0 48 c7 c6 18 b8 30 a6 e8 d7 f8 fc ff <0f> 0b 48 8d 78 ff eb bc 48 8b 07 a9 00 00 01 00 74 3a 66 90 0f b6 [ 41.310235] RSP: 0018:ffffac05c2a6bc78 EFLAGS: 00010292 [ 41.311201] RAX: 000000000000003e RBX: 0000000000000000 RCX: 0000000000000000 [ 41.312502] RDX: 0000000000000001 RSI: ffffffffa6423004 RDI: 00000000ffffffff [ 41.313794] RBP: ffff993c98823600 R08: 0000000000000000 R09: 00000000ffffdfff [ 41.315089] R10: ffffac05c2a6ba68 R11: ffffffffa698ca28 R12: ffff993c98823600 [ 41.316398] R13: ffff993c86311ebc R14: 0000000000000000 R15: 000000000000005c [ 41.317700] FS: 00007fe13fc56740(0000) GS:ffff993cdd900000(0000) knlGS:0000000000000000 [ 41.319150] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 41.320152] CR2: 000000c00008a000 CR3: 0000000014908000 CR4: 0000000000350ee0 [ 41.321387] Call Trace: [ 41.321819] [ 41.322193] skb_release_data+0x13f/0x1c0 [ 41.322902] __kfree_skb+0x20/0x30 [ 41.343870] tcp_recvmsg_locked+0x671/0x880 [ 41.363764] tcp_recvmsg+0x5e/0x1c0 [ 41.384102] inet_recvmsg+0x42/0x100 [ 41.406783] ? sock_recvmsg+0x1d/0x70 [ 41.428201] sock_read_iter+0x84/0xd0 [ 41.445592] ? 0xffffffffa3000000 [ 41.462442] new_sync_read+0x148/0x160 [ 41.479314] ? 0xffffffffa3000000 [ 41.496937] vfs_read+0x138/0x190 [ 41.517198] ksys_read+0x87/0xc0 [ 41.535336] do_syscall_64+0x3b/0x90 [ 41.551637] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 41.568050] RIP: 0033:0x48765b [ 41.583955] Code: e8 4a 35 fe ff eb 88 cc cc cc cc cc cc cc cc e8 fb 7a fe ff 48 8b 7c 24 10 48 8b 74 24 18 48 8b 54 24 20 48 8b 44 24 08 0f 05 <48> 3d 01 f0 ff ff 76 20 48 c7 44 24 28 ff ff ff ff 48 c7 44 24 30 [ 41.632818] RSP: 002b:000000c000a2f5b8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 41.664588] RAX: ffffffffffffffda RBX: 000000c000062000 RCX: 000000000048765b [ 41.681205] RDX: 0000000000005e54 RSI: 000000c000e66000 RDI: 0000000000000016 [ 41.697164] RBP: 000000c000a2f608 R08: 0000000000000001 R09: 00000000000001b4 [ 41.713034] R10: 00000000000000b6 R11: 0000000000000212 R12: 00000000000000e9 [ 41.728755] R13: 0000000000000001 R14: 000000c000a92000 R15: ffffffffffffffff [ 41.744254] [ 41.758585] Modules linked in: br_netfilter bridge veth netconsole virtio_net and [ 33.524802] BUG: Bad page state in process systemd-network pfn:11e60 [ 33.528617] page ffffe05dc0147b00 ffffe05dc04e7a00 ffff8ae9851ec000 (1) len 82 offset 252 metasize 4 hroom 0 hdr_len 12 data ffff8ae9851ec10c data_meta ffff8ae9851ec108 data_end ffff8ae9851ec14e [ 33.529764] page:000000003792b5ba refcount:0 mapcount:-512 mapping:0000000000000000 index:0x0 pfn:0x11e60 [ 33.532463] flags: 0xfffffc0000000(node=0|zone=1|lastcpupid=0x1fffff) [ 33.532468] raw: 000fffffc0000000 0000000000000000 dead000000000122 0000000000000000 [ 33.532470] raw: 0000000000000000 0000000000000000 00000000fffffdff 0000000000000000 [ 33.532471] page dumped because: nonzero mapcount [ 33.532472] Modules linked in: br_netfilter bridge veth netconsole virtio_net [ 33.532479] CPU: 0 PID: 791 Comm: systemd-network Kdump: loaded Not tainted 5.18.0-rc1+ #37 [ 33.532482] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1.fc35 04/01/2014 [ 33.532484] Call Trace: [ 33.532496] [ 33.532500] dump_stack_lvl+0x45/0x5a [ 33.532506] bad_page.cold+0x63/0x94 [ 33.532510] free_pcp_prepare+0x290/0x420 [ 33.532515] free_unref_page+0x1b/0x100 [ 33.532518] skb_release_data+0x13f/0x1c0 [ 33.532524] kfree_skb_reason+0x3e/0xc0 [ 33.532527] ip6_mc_input+0x23c/0x2b0 [ 33.532531] ip6_sublist_rcv_finish+0x83/0x90 [ 33.532534] ip6_sublist_rcv+0x22b/0x2b0 [3] XDP program to reproduce(xdp_pass.c): #include #include SEC("xdp_pass") int xdp_pkt_pass(struct xdp_md *ctx) { bpf_xdp_adjust_head(ctx, -(int)32); return XDP_PASS; } char _license[] SEC("license") = "GPL"; compile: clang -O2 -g -Wall -target bpf -c xdp_pass.c -o xdp_pass.o load on virtio_net: ip link set enp1s0 xdpdrv obj xdp_pass.o sec xdp_pass CC: stable@vger.kernel.org CC: Jason Wang CC: Xuan Zhuo CC: Daniel Borkmann CC: "Michael S. Tsirkin" CC: virtualization@lists.linux-foundation.org Fixes: 8fb7da9e9907 ("virtio_net: get build_skb() buf by data ptr") Signed-off-by: Nikolay Aleksandrov --- drivers/net/virtio_net.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 87838cbe38cf..0687dd88e97f 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -434,9 +434,13 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, * Buffers with headroom use PAGE_SIZE as alloc size, see * add_recvbuf_mergeable() + get_mergeable_buf_len() */ - truesize = headroom ? PAGE_SIZE : truesize; + if (headroom) { + truesize = PAGE_SIZE; + buf = (char *)((unsigned long)p & PAGE_MASK); + } else { + buf = p; + } tailroom = truesize - headroom; - buf = p - headroom; len -= hdr_len; offset += hdr_padded_len; -- 2.35.1 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from smtp3.osuosl.org (smtp3.osuosl.org [140.211.166.136]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2DB25C433FE for ; Sat, 23 Apr 2022 11:26:23 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id C8A0360C30; Sat, 23 Apr 2022 11:26:22 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id nmG2H7N90ucn; Sat, 23 Apr 2022 11:26:21 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [140.211.9.56]) by smtp3.osuosl.org (Postfix) with ESMTPS id 349CA60AFF; Sat, 23 Apr 2022 11:26:21 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 02FABC0039; Sat, 23 Apr 2022 11:26:21 +0000 (UTC) Received: from smtp3.osuosl.org (smtp3.osuosl.org [IPv6:2605:bc80:3010::136]) by lists.linuxfoundation.org (Postfix) with ESMTP id 54AC9C002D for ; Sat, 23 Apr 2022 11:26:19 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id 3B84460C15 for ; Sat, 23 Apr 2022 11:26:19 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id vaTisuUIAKy7 for ; Sat, 23 Apr 2022 11:26:18 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.8.0 Received: from mail-ej1-x62c.google.com (mail-ej1-x62c.google.com [IPv6:2a00:1450:4864:20::62c]) by smtp3.osuosl.org (Postfix) with ESMTPS id D267A60AFF for ; Sat, 23 Apr 2022 11:26:17 +0000 (UTC) Received: by mail-ej1-x62c.google.com with SMTP id t11so20872639eju.13 for ; Sat, 23 Apr 2022 04:26:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=blackwall-org.20210112.gappssmtp.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=R55cctVnDSIYjYkatNLitr0ArQTcklMikj4+Ic6cAKg=; b=erJbMPNnIOT+22gFdm3LWgYV0fgA1wb7MgoBN5qxI0I0mvBsjKWTJw1UIXhhoZpGlj pQYdAwifQWxNJzJe9sJ9tD+s1nKOSNrFa8vyjHY1KebNaD/f2uu1oan/mMiQO5lb7cAG ouhGWKZ0fh8xnrRS84UHwovhspdXt513Ev2Dt5JJjPeT2IcSGSIEDz8tyZ6FffdrVmg7 J+PhyF1iUTe1lxu9bB4d2TULYnP93sLVRZswjytxxAuI+7XdYahOLEoIkgAFptx9zjUi ll5JUxYSzKeCrt1KUa/5/Bpo2UtN9Hh0YKyZaOEuV8QnuEbjJYRmkQ2zNLp8ahOr+n+G /2Ag== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=R55cctVnDSIYjYkatNLitr0ArQTcklMikj4+Ic6cAKg=; b=VN7VcfYGD+hMu1vk7bizZ3OI+FvlHFrMhG1Nc6YTmRfjN3oodhFdu1ryiRWRd/fRdI KfhgoIJKSnFfr7mAAr56IKU2WcQUn05LA3Iz7+NUFYx+ycK8V2oTYRkSFibbGdETwIHr osfUhNT7ww0SGbD30cCsy4xOYVwlFVXcj1JahO0EhHK/JnDtUH2BLqrEKPMPycysyunn UPw2pP+SIsmqR/sqBrBxyF59/e0y1JXjVLNnIZGoicb3nSEgRd/C8fqah7TQF94LBtNC Nct1HUPGO06HfcIRH9ndUmryr2xP/u9D+/6e53G8iaCSVxE5V6lwKFIZN8MPAOnPZ74y /jEA== X-Gm-Message-State: AOAM533tycF8pHVX0wZdI3hiV35ApxOY4pM/kKHB2Rrtc5dQKbN7zFAM D9H+zbG9D4PbysE59oxE96XTNQ== X-Google-Smtp-Source: ABdhPJwDSahCbjVD5h1/H5H7a0X0JfYBL9mDd6r+7XqDUQSVtRcVnjP5Tw1CJi2ljaUYgw0M90XH9Q== X-Received: by 2002:a17:907:720d:b0:6f0:fa7b:fca1 with SMTP id dr13-20020a170907720d00b006f0fa7bfca1mr7092405ejc.514.1650713175763; Sat, 23 Apr 2022 04:26:15 -0700 (PDT) Received: from debil.. (87-243-81-1.ip.btc-net.bg. [87.243.81.1]) by smtp.gmail.com with ESMTPSA id e19-20020a056402105300b004162d0b4cbbsm2077897edu.93.2022.04.23.04.26.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 23 Apr 2022 04:26:15 -0700 (PDT) From: Nikolay Aleksandrov To: netdev@vger.kernel.org Subject: [PATCH net] virtio_net: fix wrong buf address calculation when using xdp Date: Sat, 23 Apr 2022 14:26:12 +0300 Message-Id: <20220423112612.2292774-1-razor@blackwall.org> X-Mailer: git-send-email 2.35.1 MIME-Version: 1.0 Cc: Daniel Borkmann , "Michael S. Tsirkin" , stable@vger.kernel.org, davem@davemloft.net, kuba@kernel.org, virtualization@lists.linux-foundation.org, Nikolay Aleksandrov X-BeenThere: virtualization@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux virtualization List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" We received a report[1] of kernel crashes when Cilium is used in XDP mode with virtio_net after updating to newer kernels. After investigating the reason it turned out that when using mergeable bufs with an XDP program which adjusts xdp.data or xdp.data_meta page_to_buf() calculates the build_skb address wrong because the offset can become less than the headroom so it gets the address of the previous page (-X bytes depending on how lower offset is): page_to_skb: page addr ffff9eb2923e2000 buf ffff9eb2923e1ffc offset 252 headroom 256 This is a pr_err() I added in the beginning of page_to_skb which clearly shows offset that is less than headroom by adding 4 bytes of metadata via an xdp prog. The calculations done are: receive_mergeable(): headroom = VIRTIO_XDP_HEADROOM; // VIRTIO_XDP_HEADROOM == 256 bytes offset = xdp.data - page_address(xdp_page) - vi->hdr_len - metasize; page_to_skb(): p = page_address(page) + offset; ... buf = p - headroom; Now buf goes -4 bytes from the page's starting address as can be seen above which is set as skb->head and skb->data by build_skb later. Depending on what's done with the skb (when it's freed most often) we get all kinds of corruptions and BUG_ON() triggers in mm[2]. The story of the faulty commit is interesting because the patch was sent and applied twice (it seems the first one got lost during merge back in 5.13 window). The first version of the patch that was applied as: commit 7bf64460e3b2 ("virtio-net: get build_skb() buf by data ptr") was actually correct because it calculated the page starting address without relying on offset or headroom, but then the second version that was applied as: commit 8fb7da9e9907 ("virtio_net: get build_skb() buf by data ptr") was wrong and added the above calculation. An example xdp prog[3] is below. [1] https://github.com/cilium/cilium/issues/19453 [2] Two of the many traces: [ 40.437400] BUG: Bad page state in process swapper/0 pfn:14940 [ 40.916726] BUG: Bad page state in process systemd-resolve pfn:053b7 [ 41.300891] kernel BUG at include/linux/mm.h:720! [ 41.301801] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI [ 41.302784] CPU: 1 PID: 1181 Comm: kubelet Kdump: loaded Tainted: G B W 5.18.0-rc1+ #37 [ 41.304458] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1.fc35 04/01/2014 [ 41.306018] RIP: 0010:page_frag_free+0x79/0xe0 [ 41.306836] Code: 00 00 75 ea 48 8b 07 a9 00 00 01 00 74 e0 48 8b 47 48 48 8d 50 ff a8 01 48 0f 45 fa eb d0 48 c7 c6 18 b8 30 a6 e8 d7 f8 fc ff <0f> 0b 48 8d 78 ff eb bc 48 8b 07 a9 00 00 01 00 74 3a 66 90 0f b6 [ 41.310235] RSP: 0018:ffffac05c2a6bc78 EFLAGS: 00010292 [ 41.311201] RAX: 000000000000003e RBX: 0000000000000000 RCX: 0000000000000000 [ 41.312502] RDX: 0000000000000001 RSI: ffffffffa6423004 RDI: 00000000ffffffff [ 41.313794] RBP: ffff993c98823600 R08: 0000000000000000 R09: 00000000ffffdfff [ 41.315089] R10: ffffac05c2a6ba68 R11: ffffffffa698ca28 R12: ffff993c98823600 [ 41.316398] R13: ffff993c86311ebc R14: 0000000000000000 R15: 000000000000005c [ 41.317700] FS: 00007fe13fc56740(0000) GS:ffff993cdd900000(0000) knlGS:0000000000000000 [ 41.319150] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 41.320152] CR2: 000000c00008a000 CR3: 0000000014908000 CR4: 0000000000350ee0 [ 41.321387] Call Trace: [ 41.321819] [ 41.322193] skb_release_data+0x13f/0x1c0 [ 41.322902] __kfree_skb+0x20/0x30 [ 41.343870] tcp_recvmsg_locked+0x671/0x880 [ 41.363764] tcp_recvmsg+0x5e/0x1c0 [ 41.384102] inet_recvmsg+0x42/0x100 [ 41.406783] ? sock_recvmsg+0x1d/0x70 [ 41.428201] sock_read_iter+0x84/0xd0 [ 41.445592] ? 0xffffffffa3000000 [ 41.462442] new_sync_read+0x148/0x160 [ 41.479314] ? 0xffffffffa3000000 [ 41.496937] vfs_read+0x138/0x190 [ 41.517198] ksys_read+0x87/0xc0 [ 41.535336] do_syscall_64+0x3b/0x90 [ 41.551637] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 41.568050] RIP: 0033:0x48765b [ 41.583955] Code: e8 4a 35 fe ff eb 88 cc cc cc cc cc cc cc cc e8 fb 7a fe ff 48 8b 7c 24 10 48 8b 74 24 18 48 8b 54 24 20 48 8b 44 24 08 0f 05 <48> 3d 01 f0 ff ff 76 20 48 c7 44 24 28 ff ff ff ff 48 c7 44 24 30 [ 41.632818] RSP: 002b:000000c000a2f5b8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 41.664588] RAX: ffffffffffffffda RBX: 000000c000062000 RCX: 000000000048765b [ 41.681205] RDX: 0000000000005e54 RSI: 000000c000e66000 RDI: 0000000000000016 [ 41.697164] RBP: 000000c000a2f608 R08: 0000000000000001 R09: 00000000000001b4 [ 41.713034] R10: 00000000000000b6 R11: 0000000000000212 R12: 00000000000000e9 [ 41.728755] R13: 0000000000000001 R14: 000000c000a92000 R15: ffffffffffffffff [ 41.744254] [ 41.758585] Modules linked in: br_netfilter bridge veth netconsole virtio_net and [ 33.524802] BUG: Bad page state in process systemd-network pfn:11e60 [ 33.528617] page ffffe05dc0147b00 ffffe05dc04e7a00 ffff8ae9851ec000 (1) len 82 offset 252 metasize 4 hroom 0 hdr_len 12 data ffff8ae9851ec10c data_meta ffff8ae9851ec108 data_end ffff8ae9851ec14e [ 33.529764] page:000000003792b5ba refcount:0 mapcount:-512 mapping:0000000000000000 index:0x0 pfn:0x11e60 [ 33.532463] flags: 0xfffffc0000000(node=0|zone=1|lastcpupid=0x1fffff) [ 33.532468] raw: 000fffffc0000000 0000000000000000 dead000000000122 0000000000000000 [ 33.532470] raw: 0000000000000000 0000000000000000 00000000fffffdff 0000000000000000 [ 33.532471] page dumped because: nonzero mapcount [ 33.532472] Modules linked in: br_netfilter bridge veth netconsole virtio_net [ 33.532479] CPU: 0 PID: 791 Comm: systemd-network Kdump: loaded Not tainted 5.18.0-rc1+ #37 [ 33.532482] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1.fc35 04/01/2014 [ 33.532484] Call Trace: [ 33.532496] [ 33.532500] dump_stack_lvl+0x45/0x5a [ 33.532506] bad_page.cold+0x63/0x94 [ 33.532510] free_pcp_prepare+0x290/0x420 [ 33.532515] free_unref_page+0x1b/0x100 [ 33.532518] skb_release_data+0x13f/0x1c0 [ 33.532524] kfree_skb_reason+0x3e/0xc0 [ 33.532527] ip6_mc_input+0x23c/0x2b0 [ 33.532531] ip6_sublist_rcv_finish+0x83/0x90 [ 33.532534] ip6_sublist_rcv+0x22b/0x2b0 [3] XDP program to reproduce(xdp_pass.c): #include #include SEC("xdp_pass") int xdp_pkt_pass(struct xdp_md *ctx) { bpf_xdp_adjust_head(ctx, -(int)32); return XDP_PASS; } char _license[] SEC("license") = "GPL"; compile: clang -O2 -g -Wall -target bpf -c xdp_pass.c -o xdp_pass.o load on virtio_net: ip link set enp1s0 xdpdrv obj xdp_pass.o sec xdp_pass CC: stable@vger.kernel.org CC: Jason Wang CC: Xuan Zhuo CC: Daniel Borkmann CC: "Michael S. Tsirkin" CC: virtualization@lists.linux-foundation.org Fixes: 8fb7da9e9907 ("virtio_net: get build_skb() buf by data ptr") Signed-off-by: Nikolay Aleksandrov --- drivers/net/virtio_net.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 87838cbe38cf..0687dd88e97f 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -434,9 +434,13 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, * Buffers with headroom use PAGE_SIZE as alloc size, see * add_recvbuf_mergeable() + get_mergeable_buf_len() */ - truesize = headroom ? PAGE_SIZE : truesize; + if (headroom) { + truesize = PAGE_SIZE; + buf = (char *)((unsigned long)p & PAGE_MASK); + } else { + buf = p; + } tailroom = truesize - headroom; - buf = p - headroom; len -= hdr_len; offset += hdr_padded_len; -- 2.35.1 _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization