From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 3E98A3C1082 for ; Mon, 21 Sep 2026 23:18:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790032742; cv=none; b=MrCDM4gVp7/Wa3xXdOZq3YZQJZK49vrX2tvYebpaFerwyYTjRYVFlQpP9NYhCaZMqogc09af0qzUTBlEmo7/VP8cARgy5hRYtFpg0tOFxFSsgI6Aqjh7PAKzuLm6tLXBhV2bLF8JHNXsZFYpRd0ec39GfC9o2MmR2365nPyJ8vU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790032742; c=relaxed/simple; bh=inaM+27U3/MAGiRQ3AimAn70uQMMSOfNqIIVPN7MUiI=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=H4wzc072CBe9Sq3rksDxJrsf9ykLY/SyCrLodEcSKaQB4nknCB1jfBG7PHcMOrhGjcU0/2dp6A0sz/7WNQNJfa3WGjXH2cep+VEzP3V8p8m8ISoHmHCEkq+pjJaQppmxBWPbWCFNZS52RmY0r5DA7CKv4iDJGxL3OtBOPxZxVyg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=jx7nPxxN; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="jx7nPxxN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 69F131F000FF; Mon, 21 Sep 2026 23:18:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1790032739; bh=kNPfaY6M/KntAfvIL3A0HWX6z6fFLRHArBcCfdRKn64=; h=From:To:Cc:Subject:Date; b=jx7nPxxN3Mj3q16duBShgN6ec4tUDc1lWCPjMp1j6yjr9uZxvzCo2m8awqzAFere/ JJ0yKJb2i/qaJU61C3hPS+4S91nZRs1NqEzoxV+gXPdgdDJPv7uxWn/930CK43WWj1 ya2sqzgZEIdvRr0+vrCs15cZY91eSiu+EV+i3jk9QfA3GZQgL7xw4QTe7QC0rT0Ynd MktMZWQQihNc19RUz/FIpymMoYnGmrwQMDyOfyoboK9nzDVFmxe+oc/tnzPzeKCMYb 5X4O1HmbleYkap6QuvsmIAGr524Cx/ZO4JDoUemWxGkvnLPZ0Nw+Thu1PmHyMPMJiJ UavyqQXrIiAew== From: Jakub Kicinski To: davem@davemloft.net Cc: netdev@vger.kernel.org, edumazet@google.com, pabeni@redhat.com, andrew+netdev@lunn.ch, horms@kernel.org, Jakub Kicinski , Weiming Shi Subject: [PATCH net v2] veth: manage XDP program pointers during channel resize Date: Mon, 21 Sep 2026 16:18:56 -0700 Message-ID: <20260921231856.1798630-1-kuba@kernel.org> X-Mailer: git-send-email 2.55.0 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit veth_set_channels() tears down XDP resources for removed RX queues without clearing rq->xdp_prog. If the program is then detached or replaced, those queues keep the old pointer after bpf_prog_put(). A later channel increase can re-enable NAPI and run the freed program. BUG: unable to handle page fault for address: ffffc90000256048 Oops: Oops: 0000 [#1] SMP KASAN NOPTI RIP: veth_xdp_rcv_skb (include/linux/filter.h:779 include/net/xdp.h:696 drivers/net/veth.c:820) Call Trace: veth_xdp_rcv (drivers/net/veth.c:941) veth_poll (drivers/net/veth.c:986) __napi_poll (net/core/dev.c:7787) net_rx_action (net/core/dev.c:7850 net/core/dev.c:8007) handle_softirqs (kernel/softirq.c:645) Kernel panic - not syncing: Fatal exception in interrupt Fixes: 4752eeb3d891 ("veth: implement support for set_channel ethtool op") Signed-off-by: Weiming Shi Signed-off-by: Jakub Kicinski --- v2: - different placement to avoid extra loops v1: https://lore.kernel.org/20260917153923.904124-3-bestswngs@gmail.com --- drivers/net/veth.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/veth.c b/drivers/net/veth.c index 6ed3ee81153f..71227d0389aa 100644 --- a/drivers/net/veth.c +++ b/drivers/net/veth.c @@ -1054,6 +1054,7 @@ static int __veth_napi_enable_range(struct net_device *dev, int start, int end) for (i = start; i < end; i++) { struct veth_rq *rq = &priv->rq[i]; + rcu_assign_pointer(rq->xdp_prog, priv->_xdp_prog); napi_enable(&rq->xdp_napi); rcu_assign_pointer(priv->rq[i].napi, &priv->rq[i].xdp_napi); } @@ -1088,6 +1089,7 @@ static void veth_napi_del_range(struct net_device *dev, int start, int end) rcu_assign_pointer(priv->rq[i].napi, NULL); napi_disable(&rq->xdp_napi); + rcu_assign_pointer(rq->xdp_prog, NULL); __netif_napi_del(&rq->xdp_napi); } synchronize_net(); -- 2.55.0