From patchwork Wed Sep 11 08:41:18 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Florian Kauer X-Patchwork-Id: 13799889 X-Patchwork-Delegate: bpf@iogearbox.net Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 7878114B970; Wed, 11 Sep 2024 08:41:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726044108; cv=none; b=kYDvXPmLapLKwSUG6oR6RCbYQQNiH2qCZOWxGWg2TKKc49RF59at1peO/d0A/eUPyiYto98b9CrMBx3lrqUWibpbbNdsj72icyhbGCo8cIepeaZODl4s/xkNRIup6fQWIFtZ0/ebYrjhQXAOOgfwLrETLIRchrK2OUcv4UdT3TA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726044108; c=relaxed/simple; bh=v9ASjx4AkQY74pBrfJHdygw7QDJW6F3tTHqu14JlvZQ=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=PXVLoR8FA6XmM5alwEExo9lFNkj1hafzBC8AOKuHsry81oZFt2lNvfbmoRyiL6UU/wMFKkgfRBPeklBbtC4siOfDTdQHqMQ7u6jUg0gbYPCfRaPpIYuVYiv/O3D9Hj/1drUe6NBLW0yduKOwzs77vw2IKUDHDgEcl/AQANTPF4c= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=bhEgXQSc; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=cgc+CZrE; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="bhEgXQSc"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="cgc+CZrE" From: Florian Kauer DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1726044104; 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=YCULmNkmiSeT1SnEcJ8wNOTPBOtklSrol+/kqbWcEAw=; b=bhEgXQSchtWH18gcr/HQvYUvbrCM5iUrelOA3cYXRu2Z2rjbaOFLJp4vfEgMAJ6ON4fUj9 h5ab+Ue0Z4pyENaHcsTdhMgEpRPFdcoVcENP2iCnW9j9p8oi4HgVpHWRnuoAZ/7x4YjNYc aV3A07+P2zYL4ctwI3KpUNl+UgwjvbrPh+6V6FOx/iqe0b0uSId0iMNY6eILEswFZpoofU O/caQdLc8qSKpzwsQR/L4nf0R27zZsb1mxnLp6Hau33HTH8escjmT+INByNHV6r+ImWQVk zwgSx4qygAjREsU1RQW4pOYosOWBwt3pllzOLaXVny9bQYXlPzGdqf7mFJlM0A== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1726044104; 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=YCULmNkmiSeT1SnEcJ8wNOTPBOtklSrol+/kqbWcEAw=; b=cgc+CZrExZcJBwgesbkqbRhd18JSytXbxsLH0ZWByVL9LopJH8Kp3EZgGlW4nBkL0jirOh RAnBPCi1jxqPkGAw== Date: Wed, 11 Sep 2024 10:41:18 +0200 Subject: [PATCH net v4 1/2] bpf: devmap: provide rxq after redirect Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240911-devel-koalo-fix-ingress-ifindex-v4-1-5c643ae10258@linutronix.de> References: <20240911-devel-koalo-fix-ingress-ifindex-v4-0-5c643ae10258@linutronix.de> In-Reply-To: <20240911-devel-koalo-fix-ingress-ifindex-v4-0-5c643ae10258@linutronix.de> To: Alexei Starovoitov , Daniel Borkmann , "David S. Miller" , Jakub Kicinski , Jesper Dangaard Brouer , John Fastabend , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= , David Ahern , Hangbin Liu , Mykola Lysenko , Shuah Khan Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, Jesper Dangaard Brouer , linux-kselftest@vger.kernel.org, Florian Kauer X-Developer-Signature: v=1; a=openpgp-sha256; l=6103; i=florian.kauer@linutronix.de; h=from:subject:message-id; bh=v9ASjx4AkQY74pBrfJHdygw7QDJW6F3tTHqu14JlvZQ=; b=owEBbQKS/ZANAwAKATKF5IolV+EkAcsmYgBm4Ve6MPcHYthOpj3QwG5K34ri6AzSgCcjk1qED WBLEst0UgaJAjMEAAEKAB0WIQSG5cmCLvpm5t9g7UUyheSKJVfhJAUCZuFXugAKCRAyheSKJVfh JMDyEADPwFul85JXxTF8VCeFcGCpddTKFHKcTtinJg5aFdccvcfNtX58rf37Zy96r5/1Y8+PqvJ 9ccHqzanZyPzf0IR8W6+VcLfd2pBm9PpMnrIGyKIvS2nhxNc5mRnDmXkjEYtGXDnLyDH5bqp8EU PHe6pf+N92MkRuSoaaJJ7B094BsuGKhxtawnBhFCoVb2u7e61Yy4S/d0UGxQzlbk/dBA++Nrl3M ArUPQNW4GLnY7uFn8HxA+RKka3wE2xZB8ThBKzPcZv5Os4v+OBgtTEpcK/laF2YC7IqC6MiVPA3 HQxQvxVhgs4vx3WIAVUnIlxADuCRDsOGSH78R73lSDMJLCLcbYYHM9FOcCtQsS/dJLiDsc2NQSS lHZQPdu7UfXKDefx0WdiqZ+Zot9sJW90/UuQsmU36y4X0Q+7ApHnv7UrUQ5uzTlbcoklL4Psv4T bT5xxQftzE/waB0vmIx386+SxGw2PkuEmwfCBk2iQzkxKbNKFrqevv8sJ+lCgMwiL6HmW4blCGu OKEc/rP1pjeQTi3micI5v6NK5r0fpt1x/5ovkA/LY0ScLEb+KMLbFLSDx5cMcy2xyrQk4S3YzFh s9kEGb6InEsHN/TQ0iXQmeeEIJqzANEE37owboXc5Rp3wy66PfTimvXSbvn8xebs2oZ/sw/+wIC k2inveGEOsEu9GQ== X-Developer-Key: i=florian.kauer@linutronix.de; a=openpgp; fpr=F17D8B54133C2229493E64A0B5976DD65251944E X-Patchwork-Delegate: kuba@kernel.org rxq contains a pointer to the device from where the redirect happened. Currently, the BPF program that was executed after a redirect via BPF_MAP_TYPE_DEVMAP* does not have it set. This is particularly bad since accessing ingress_ifindex, e.g. SEC("xdp") int prog(struct xdp_md *pkt) { return bpf_redirect_map(&dev_redirect_map, 0, 0); } SEC("xdp/devmap") int prog_after_redirect(struct xdp_md *pkt) { bpf_printk("ifindex %i", pkt->ingress_ifindex); return XDP_PASS; } depends on access to rxq, so a NULL pointer gets dereferenced: <1>[ 574.475170] BUG: kernel NULL pointer dereference, address: 0000000000000000 <1>[ 574.475188] #PF: supervisor read access in kernel mode <1>[ 574.475194] #PF: error_code(0x0000) - not-present page <6>[ 574.475199] PGD 0 P4D 0 <4>[ 574.475207] Oops: Oops: 0000 [#1] PREEMPT SMP NOPTI <4>[ 574.475217] CPU: 4 UID: 0 PID: 217 Comm: kworker/4:1 Not tainted 6.11.0-rc5-reduced-00859-g780801200300 #23 <4>[ 574.475226] Hardware name: Intel(R) Client Systems NUC13ANHi7/NUC13ANBi7, BIOS ANRPL357.0026.2023.0314.1458 03/14/2023 <4>[ 574.475231] Workqueue: mld mld_ifc_work <4>[ 574.475247] RIP: 0010:bpf_prog_5e13354d9cf5018a_prog_after_redirect+0x17/0x3c <4>[ 574.475257] Code: cc cc cc cc cc cc cc 80 00 00 00 cc cc cc cc cc cc cc cc f3 0f 1e fa 0f 1f 44 00 00 66 90 55 48 89 e5 f3 0f 1e fa 48 8b 57 20 <48> 8b 52 00 8b 92 e0 00 00 00 48 bf f8 a6 d5 c4 5d a0 ff ff be 0b <4>[ 574.475263] RSP: 0018:ffffa62440280c98 EFLAGS: 00010206 <4>[ 574.475269] RAX: ffffa62440280cd8 RBX: 0000000000000001 RCX: 0000000000000000 <4>[ 574.475274] RDX: 0000000000000000 RSI: ffffa62440549048 RDI: ffffa62440280ce0 <4>[ 574.475278] RBP: ffffa62440280c98 R08: 0000000000000002 R09: 0000000000000001 <4>[ 574.475281] R10: ffffa05dc8b98000 R11: ffffa05f577fca40 R12: ffffa05dcab24000 <4>[ 574.475285] R13: ffffa62440280ce0 R14: ffffa62440549048 R15: ffffa62440549000 <4>[ 574.475289] FS: 0000000000000000(0000) GS:ffffa05f4f700000(0000) knlGS:0000000000000000 <4>[ 574.475294] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 <4>[ 574.475298] CR2: 0000000000000000 CR3: 000000025522e000 CR4: 0000000000f50ef0 <4>[ 574.475303] PKRU: 55555554 <4>[ 574.475306] Call Trace: <4>[ 574.475313] <4>[ 574.475318] ? __die+0x23/0x70 <4>[ 574.475329] ? page_fault_oops+0x180/0x4c0 <4>[ 574.475339] ? skb_pp_cow_data+0x34c/0x490 <4>[ 574.475346] ? kmem_cache_free+0x257/0x280 <4>[ 574.475357] ? exc_page_fault+0x67/0x150 <4>[ 574.475368] ? asm_exc_page_fault+0x26/0x30 <4>[ 574.475381] ? bpf_prog_5e13354d9cf5018a_prog_after_redirect+0x17/0x3c <4>[ 574.475386] bq_xmit_all+0x158/0x420 <4>[ 574.475397] __dev_flush+0x30/0x90 <4>[ 574.475407] veth_poll+0x216/0x250 [veth] <4>[ 574.475421] __napi_poll+0x28/0x1c0 <4>[ 574.475430] net_rx_action+0x32d/0x3a0 <4>[ 574.475441] handle_softirqs+0xcb/0x2c0 <4>[ 574.475451] do_softirq+0x40/0x60 <4>[ 574.475458] <4>[ 574.475461] <4>[ 574.475464] __local_bh_enable_ip+0x66/0x70 <4>[ 574.475471] __dev_queue_xmit+0x268/0xe40 <4>[ 574.475480] ? selinux_ip_postroute+0x213/0x420 <4>[ 574.475491] ? alloc_skb_with_frags+0x4a/0x1d0 <4>[ 574.475502] ip6_finish_output2+0x2be/0x640 <4>[ 574.475512] ? nf_hook_slow+0x42/0xf0 <4>[ 574.475521] ip6_finish_output+0x194/0x300 <4>[ 574.475529] ? __pfx_ip6_finish_output+0x10/0x10 <4>[ 574.475538] mld_sendpack+0x17c/0x240 <4>[ 574.475548] mld_ifc_work+0x192/0x410 <4>[ 574.475557] process_one_work+0x15d/0x380 <4>[ 574.475566] worker_thread+0x29d/0x3a0 <4>[ 574.475573] ? __pfx_worker_thread+0x10/0x10 <4>[ 574.475580] ? __pfx_worker_thread+0x10/0x10 <4>[ 574.475587] kthread+0xcd/0x100 <4>[ 574.475597] ? __pfx_kthread+0x10/0x10 <4>[ 574.475606] ret_from_fork+0x31/0x50 <4>[ 574.475615] ? __pfx_kthread+0x10/0x10 <4>[ 574.475623] ret_from_fork_asm+0x1a/0x30 <4>[ 574.475635] <4>[ 574.475637] Modules linked in: veth br_netfilter bridge stp llc iwlmvm x86_pkg_temp_thermal iwlwifi efivarfs nvme nvme_core <4>[ 574.475662] CR2: 0000000000000000 <4>[ 574.475668] ---[ end trace 0000000000000000 ]--- Therefore, provide it to the program by setting rxq properly. Fixes: cb261b594b41 ("bpf: Run devmap xdp_prog on flush instead of bulk enqueue") Reviewed-by: Toke Høiland-Jørgensen Signed-off-by: Florian Kauer Acked-by: Jakub Kicinski --- kernel/bpf/devmap.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c index 9e0e3b0a18e4..7878be18e9d2 100644 --- a/kernel/bpf/devmap.c +++ b/kernel/bpf/devmap.c @@ -333,9 +333,11 @@ static int dev_map_hash_get_next_key(struct bpf_map *map, void *key, static int dev_map_bpf_prog_run(struct bpf_prog *xdp_prog, struct xdp_frame **frames, int n, - struct net_device *dev) + struct net_device *tx_dev, + struct net_device *rx_dev) { - struct xdp_txq_info txq = { .dev = dev }; + struct xdp_txq_info txq = { .dev = tx_dev }; + struct xdp_rxq_info rxq = { .dev = rx_dev }; struct xdp_buff xdp; int i, nframes = 0; @@ -346,6 +348,7 @@ static int dev_map_bpf_prog_run(struct bpf_prog *xdp_prog, xdp_convert_frame_to_buff(xdpf, &xdp); xdp.txq = &txq; + xdp.rxq = &rxq; act = bpf_prog_run_xdp(xdp_prog, &xdp); switch (act) { @@ -360,7 +363,7 @@ static int dev_map_bpf_prog_run(struct bpf_prog *xdp_prog, bpf_warn_invalid_xdp_action(NULL, xdp_prog, act); fallthrough; case XDP_ABORTED: - trace_xdp_exception(dev, xdp_prog, act); + trace_xdp_exception(tx_dev, xdp_prog, act); fallthrough; case XDP_DROP: xdp_return_frame_rx_napi(xdpf); @@ -388,7 +391,7 @@ static void bq_xmit_all(struct xdp_dev_bulk_queue *bq, u32 flags) } if (bq->xdp_prog) { - to_send = dev_map_bpf_prog_run(bq->xdp_prog, bq->q, cnt, dev); + to_send = dev_map_bpf_prog_run(bq->xdp_prog, bq->q, cnt, dev, bq->dev_rx); if (!to_send) goto out; }