From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-182.mta0.migadu.com (out-182.mta0.migadu.com [91.218.175.182]) (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 E879B3D6F for ; Sat, 11 Oct 2025 07:05:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760166328; cv=none; b=Xhb5++GdzSP3WQXCgt5gICj/tsOPMxhmBWqclXC9/WDgzD7GT74Vkavo/AZmLUbBxW8lMizvVqNHMUdI7H1NNQ3DKpgSj4lX9W3+l8dQmcYm+lEturU+Wbfq66ImGTiVMJngJkaZC9bDK0JNGjSWjNeG50niQhHsVQuAMHQ25CU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760166328; c=relaxed/simple; bh=vlDpv4+vPU1Kjx7jtzVB2bnQ6cL+6c1veicyj2grg+w=; h=From:To:Cc:Subject:Date:Message-Id; b=tA7ffgvQKUprOysvQte7Zn6Zfaahkjg1Xgh+f9wNKgN45P/caoHpaIZRGCT3gPkczQjllyF1RQk1wQ8wuKzVC2k6PgvJ9NtaAvifnFwwsJf67X84MAK9adkcz8wInEUukeJ4Yfgha0UFqE+dDzE1ztXoBJT0u/xOPvEenqYbeCk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=eZgaCycz; arc=none smtp.client-ip=91.218.175.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="eZgaCycz" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1760166323; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc; bh=FQ8m1m2GXT9bWQmyxRgPz96qAAbzYD8eAbj3iY6tIWY=; b=eZgaCyczeUtDSazpWtF2p7FRRkfIoLqe3rACuIFOjo3bFjO058oV2g60VXWq+0e2nTCBgt SMpYMYHgbuQFW533pgUKxPpuChg9j5FkusS8g2vfNfvyDSgM3QUPDLgCe2vRuEez1Z1tcF xVmvUP5aF2/4ZhM2sxaQvJYMhm/U0fU= From: Zqiang To: oneukum@suse.com, andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com Cc: netdev@vger.kernel.org Subject: [PATCH v2] usbnet: Fix using smp_processor_id() in preemptible code warnings Date: Sat, 11 Oct 2025 15:05:18 +0800 Message-Id: <20251011070518.7095-1-qiang.zhang@linux.dev> X-Migadu-Flow: FLOW_OUT Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Syzbot reported the following warning: BUG: using smp_processor_id() in preemptible [00000000] code: dhcpcd/2879 caller is usbnet_skb_return+0x74/0x490 drivers/net/usb/usbnet.c:331 CPU: 1 UID: 0 PID: 2879 Comm: dhcpcd Not tainted 6.15.0-rc4-syzkaller-00098-g615dca38c2ea #0 PREEMPT(voluntary) Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120 check_preemption_disabled+0xd0/0xe0 lib/smp_processor_id.c:49 usbnet_skb_return+0x74/0x490 drivers/net/usb/usbnet.c:331 usbnet_resume_rx+0x4b/0x170 drivers/net/usb/usbnet.c:708 usbnet_change_mtu+0x1be/0x220 drivers/net/usb/usbnet.c:417 __dev_set_mtu net/core/dev.c:9443 [inline] netif_set_mtu_ext+0x369/0x5c0 net/core/dev.c:9496 netif_set_mtu+0xb0/0x160 net/core/dev.c:9520 dev_set_mtu+0xae/0x170 net/core/dev_api.c:247 dev_ifsioc+0xa31/0x18d0 net/core/dev_ioctl.c:572 dev_ioctl+0x223/0x10e0 net/core/dev_ioctl.c:821 sock_do_ioctl+0x19d/0x280 net/socket.c:1204 sock_ioctl+0x42f/0x6a0 net/socket.c:1311 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f For historical and portability reasons, the netif_rx() is usually run in the softirq or interrupt context, this commit therefore add local_bh_disable/enable() protection in the usbnet_resume_rx(). Fixes: 43daa96b166c ("usbnet: Stop RX Q on MTU change") Link: https://syzkaller.appspot.com/bug?id=81f55dfa587ee544baaaa5a359a060512228c1e1 Suggested-by: Jakub Kicinski Signed-off-by: Zqiang --- v1->v2 Use BH-disable protection in usbnet_resume_rx() instead of using get_cpu_ptr(dev->net->tstats) in usbnet_skb_return(). drivers/net/usb/usbnet.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c index 511c4154cf74..bf01f2728531 100644 --- a/drivers/net/usb/usbnet.c +++ b/drivers/net/usb/usbnet.c @@ -702,6 +702,7 @@ void usbnet_resume_rx(struct usbnet *dev) struct sk_buff *skb; int num = 0; + local_bh_disable(); clear_bit(EVENT_RX_PAUSED, &dev->flags); while ((skb = skb_dequeue(&dev->rxq_pause)) != NULL) { @@ -710,6 +711,7 @@ void usbnet_resume_rx(struct usbnet *dev) } queue_work(system_bh_wq, &dev->bh_work); + local_bh_enable(); netif_dbg(dev, rx_status, dev->net, "paused rx queue disabled, %d skbs requeued\n", num); -- 2.17.1