From nobody Sun Feb 8 04:18:05 2026 Received: from m16.mail.163.com (m16.mail.163.com [117.135.210.3]) (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 CD94B37AA9A; Thu, 29 Jan 2026 08:00:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=117.135.210.3 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769673606; cv=none; b=R5HZjrD4JKr6IoAvk++JThIibc02lzJPmD9xSPB6Npl5FIDPe3YutRV5z041hQpWHewehoQB2yCPZ9Z+OhApaHxwaBQN887zsA9BHgq6RuN9oc8pkZGQL3wfl5FQmDbdN8ldDhgbxazYMc3mtrzBZdHZlRoua6jbxQzx1IJixXY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769673606; c=relaxed/simple; bh=BX22US3w6B54wa3HdAMVVUnwnXndC+cpS0cG/lGQlw4=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=JaSPCvd4sIUHzg2AeYgWX1syU0dTqtBoxwLsdUIe7DrcV0xaHok/5qAXaFAgSReyuRit511nbm+Wg4JsR35TNedHgzH4NrXrK1OEu7Dn4SGZwDUJGjbZLo3/T4qtw95ofBwMSblLyQp4l915kmI0rvao+zLc7V0AOiYLo1/mSrE= 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=MZFnfoew; arc=none smtp.client-ip=117.135.210.3 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="MZFnfoew" 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=QL 3dUcAYKfEP61hZSUlNgqsKyHH43mt+E+rasKcdcC8=; b=MZFnfoewHONzFmqF62 p3hrGEWfo/JaacF4/ZUL6bI8vVPgYh7BfeV9Q7mHrrLt7GjNUsQpV6gXLbZ2RXh8 eToJ9hmgACkMrGLHl+lGkrD+4uDIsH+6MG+Gh8P9zEehYAjhpMbNZ/IGxk6YN3eR 6UPcJSzO8rnLRaJ1QKnl4jYzA= Received: from pek-lpg-core6.wrs.com (unknown []) by gzga-smtp-mtada-g1-4 (Coremail) with SMTP id _____wB3K5Y_E3tp9UGSIg--.376S2; Thu, 29 Jan 2026 15:58:56 +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 6.1.y] usbnet: Fix using smp_processor_id() in preemptible code warnings Date: Thu, 29 Jan 2026 15:58:54 +0800 Message-Id: <20260129075854.2945271-1-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: _____wB3K5Y_E3tp9UGSIg--.376S2 X-Coremail-Antispam: 1Uf129KBjvJXoWxCF4Dtr45Zryxur13CrykXwb_yoW5Zr45pF WrGr15Ar4UXF4vqayfta1IqryrZa1DJrZrGrWS9wn8ZF9xA34UXF1F93WI9F1qkr40gFyj qF4qv3y3Xw1rZa7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0pElkItUUUUU= X-CM-SenderInfo: 5eoduy4okd4yi6rwjhhfrp/xtbC3QEOp2l7E0HnRAAA3W 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 6bdf035e35f5..9a058f7c6fcd 100644 --- a/drivers/net/usb/usbnet.c +++ b/drivers/net/usb/usbnet.c @@ -704,6 +704,7 @@ 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) { @@ -712,6 +713,7 @@ 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