From patchwork Thu Sep 5 13:58:54 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Florian Kauer X-Patchwork-Id: 13792391 X-Patchwork-Delegate: kuba@kernel.org 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 7371D19DF43; Thu, 5 Sep 2024 13:59:05 +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=1725544747; cv=none; b=N65SLz5hPQkaDA29zwm55QDtDl1UKgSVKeQeT45Gt4Jm3q1GWQrKfViAUOLWt9tLPEjzVJ7bvWEg8kaI7ao7nU4OHQqk0FQ1vM3yLVhArdo74iS/8x6Hupu+f+kuUdi5p5rkju+ey7lQknu++47mOeaR39QX30n2kFa7fPIMn3Q= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725544747; c=relaxed/simple; bh=dSThtGnTvLYJRggv5LcGMVO+v4b3u7P24wvM97QtCaI=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=IJSaa5zTrYsMhs2o6Z/0yw5aHSQn7IlAB4PvA1gHthjqCW+BvacYQ3PnA1xIehEMuI9KfSQqAESjkrvQAxSgsbKt5XvACIXA/kHbCVmXHmawijQb9Sia1YNDPV2X+MSWZdNh7cUigsUDLPaOX76JOR2oESBeErVZel5fPrX4awo= 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=Qjl8o8AV; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=JfDW93ji; 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="Qjl8o8AV"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="JfDW93ji" From: Florian Kauer DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1725544743; 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; bh=0oKma/zBhW4JDcVQCdGfQNvCqgcLaeYLJeO9J9rV+Ps=; b=Qjl8o8AVLkhWTeg98SxVazKg4K8UkQhQnnFppcjW43y7jl8+OgjonlgyB9+ecIuVbbItU9 OwlJG/mL7NPhkoZ0cyQPbz3Odur0am4R5fXBwCTSCSQxzWru3QMtR1IouA8+fLeI+f6zMg yq8hkSR+63I0kCxkzO9qZMtyCYk00N4qVtySUZ/X2kCYRAAqrOBqa/GMUYhqV9y/8xYvy+ Qi47Ybw7rqL3a+GpRdU5L0CUc8Obzh3zWPTa5EKWpzJ68OkWPNmXLKW+qsOucu+pPro4IJ gqt1J5atMSdnfKBrF/OeGH5GL0nlbaM5mfJ38Pz73Vw8A/9f6lmnV3scOivEOA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1725544743; 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; bh=0oKma/zBhW4JDcVQCdGfQNvCqgcLaeYLJeO9J9rV+Ps=; b=JfDW93jiALEFeLg3mnCbhi+osaVZF3M79l9YaWB/1Wv9CU1IB4tvwV0Ki25pRKv0zRXmod SKz8tfM9Jwom0bCg== Date: Thu, 05 Sep 2024 15:58:54 +0200 Subject: [PATCH net] 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: <20240905-devel-koalo-fix-ingress-ifindex-v1-1-d12a0d74c29c@linutronix.de> X-B4-Tracking: v=1; b=H4sIAB252WYC/x2NwQrCQAwFf6XkbGC7VmX9FfHQmtcaLFnZlFIo/ XcXjwPDzE6OonC6NzsVrOqarUJ7auj17m0Cq1SmGGIXUriwYMXMn9zPmUfdWG0qcGcd1QQbDym ms3S3VoYr1cq3oGr/w4MMCz2P4wfSUxbJdgAAAA== 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 Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, Florian Kauer X-Developer-Signature: v=1; a=openpgp-sha256; l=6225; i=florian.kauer@linutronix.de; h=from:subject:message-id; bh=dSThtGnTvLYJRggv5LcGMVO+v4b3u7P24wvM97QtCaI=; b=owEBbQKS/ZANAwAKATKF5IolV+EkAcsmYgBm2bki+BH46lYC0Jsa2UCBo63Cs7pplvbrbZAjN C2EAXYgjvmJAjMEAAEKAB0WIQSG5cmCLvpm5t9g7UUyheSKJVfhJAUCZtm5IgAKCRAyheSKJVfh JExWEADhl07yzayW5CB2iS9GoKOJRVy0QFyr2qXelEsDogGNHjP8SiAnQhCay++2pkgReRiRpxv N/LMU06MDCBS8+SDK/p5zRczCt3H20SDgTTuSoJz/IQpbXcvi3+pM8ap9EvjDmBm2B1nTIXgx7O rUkfDmB8ksSsdD3FZT5dCuL9bnHHox4/Yq4r1tGZhXKFTDjgplo3GEmNHEmU0bo9OoMsLKTmnWC F5ql/AFsgt4l9sTsODSj7yARpSC8r5ieEBLva4yfeX8Uq/9H2RwxQf8CYgleYIqesgLJ+A46eW2 L4VBtcWUh6FjCYnVJ6Yo3QVzU/HwDdRprxloybFxSmdBfrCqN8yg2tOdbuPqejjdjkldeilfPE0 O84DINxbPzdWrJctg4uj8l2oImeAtuRua+uq/hwa5ki6xZ7+OR3hkEAbilQz0zhE0s4FiClVYDl oJLkdajJigdsSDCC8wYpPAIZtVtOBsLinUKNDt12lTpZEVnnMeeX3sqRuOaPYbgHGDBSgjnpCGv PHadeAD37uuku1J+9BS/OQBWBONGuEnPKEDh6schsc0JmjV8WDTemG9pLkvOSZ8gXZGYK8rlRT3 Qbkd8ylQcmLOwo+GrwdQrKRWhonkMKCXMLXYT+X1sRisk+7HbN0fD2dtP094I1OTGh1oX8bqGzR Y9+MlGRtlo/Cffg== 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: fbee97feed9b ("bpf: Add support to attach bpf program to a devmap entry") Signed-off-by: Florian Kauer Reviewed-by: Toke Høiland-Jørgensen --- kernel/bpf/devmap.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) --- base-commit: 8e69c96df771ab469cec278edb47009351de4da6 change-id: 20240905-devel-koalo-fix-ingress-ifindex-b9293d471db6 Best regards, 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; }