From nobody Sun Feb 8 04:17:51 2026 Received: from m16.mail.163.com (m16.mail.163.com [117.135.210.4]) (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 6E94138B9AF; Wed, 21 Jan 2026 06:53:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=117.135.210.4 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768978402; cv=none; b=aLvoTR2xK3PIpAraDtvmpUQ5hN2zZTlEM/h09Sbci1MvqyWc2mK0O9FIURwWW8LrXgPuycHq4VSEcw0NUnZTYevPwh28LaizzYQ9k/HlfhkJ+6c4N6qBmgP+i5TzhV7iq9XSmKHwtDECeGXOMqzjrOEtArYtvqmtDiDRqQXQBbQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768978402; c=relaxed/simple; bh=oV/b8+bprG/2ppb5+JhI3BURoaWKU1/zzpmE5b9cyGc=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=Jt2eQ8MbxnlfttxaJer7xW1RWLTP4AjkcXeL6+wdT3DV0cwraCwowwYgnGkZPE93vFCfCIvIAeObKqYku0T8kFWRDWtuoeaCnBY7GtY37RzFklYqBwb3yJa4LlK/g9yXM0a/n4mcL4BXnCIEZunhz5ZEYr2G0m1ToJJDzJyMS6c= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=b2krvPEL; arc=none smtp.client-ip=117.135.210.4 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="b2krvPEL" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=SC UD4/weMkOy3cfmmEjb4WKtHyc7re9Vr9XkzonoqiA=; b=b2krvPELIfm29cAXAh 3utUVDCzFyoU4ywvIi1ytkS1PI5AGFqQURM99/UVRP4qBwT8Q4L0loo595snTYi4 bCkYjxcihod+W6W4gFsVsRob70lIw1AEYthQAj7eD1XRcIcUvHbyCwyNrC2zyVQv WJqALQr5dYboZ5Pa5XQUQeq/A= Received: from pek-lpg-core6.wrs.com (unknown []) by gzga-smtp-mtada-g1-3 (Coremail) with SMTP id _____wDHA9qRd3Bptl5aHg--.5890S2; Wed, 21 Jan 2026 14:52:02 +0800 (CST) From: Rahul Sharma To: gregkh@linuxfoundation.org, stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Zqiang , Jakub Kicinski , Paolo Abeni , Rahul Sharma Subject: [PATCH v6.6] usbnet: Fix using smp_processor_id() in preemptible code warnings Date: Wed, 21 Jan 2026 14:51:59 +0800 Message-Id: <20260121065159.2877946-1-black.hawk@163.com> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: _____wDHA9qRd3Bptl5aHg--.5890S2 X-Coremail-Antispam: 1Uf129KBjvJXoWxCF4Dtr45Zryxur13CrykXwb_yoW5Zr45pF WrCF17Ar4UXF1vqayfta1SqryrZa1DtrZrGrWS9wn8ZF9xA34UXF1093WI9F1jkr48WFy0 qF4qv3y7Xw1rZa7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0piG2NPUUUUU= X-CM-SenderInfo: 5eoduy4okd4yi6rwjhhfrp/xtbC+hN4Emlwd5P89gAA30 Content-Type: text/plain; charset="utf-8" From: Zqiang [ Upstream commit 327cd4b68b4398b6c24f10eb2b2533ffbfc10185 ] 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=3D81f55dfa587ee544baaaa5a359a060= 512228c1e1 Suggested-by: Jakub Kicinski Signed-off-by: Zqiang Link: https://patch.msgid.link/20251011070518.7095-1-qiang.zhang@linux.dev Signed-off-by: Paolo Abeni [ The context change is due to the commit 2c04d279e857 ("net: usb: Convert tasklet API to new bottom half workqueue mechanism") in v6.17 which is irrelevant to the logic of this patch.] Signed-off-by: Rahul Sharma --- 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 e6a1864f03f9..763aa239c323 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 =3D 0; =20 + local_bh_disable(); clear_bit(EVENT_RX_PAUSED, &dev->flags); =20 while ((skb =3D skb_dequeue(&dev->rxq_pause)) !=3D NULL) { @@ -710,6 +711,7 @@ void usbnet_resume_rx(struct usbnet *dev) } =20 tasklet_schedule(&dev->bh); + local_bh_enable(); =20 netif_dbg(dev, rx_status, dev->net, "paused rx queue disabled, %d skbs requeued\n", num); --=20 2.34.1