From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 2F0F92BD012; Wed, 4 Feb 2026 15:01:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770217296; cv=none; b=reKnVR4hbl4nfwyTVlD0bYOPR7uatvFCvDlTMaPBo9rF0TUaLmQYBC7XAyrsI01TV0UQ2RqJqzbTcx83Wcm5dvxgvD0+Fgg6oFuaqWo/cGIzVOz1iB+xSZI0aXbRrYsNATRK6QQ2DJ8pKhDml1V9r9dlnT57LcPn3JV2JBDsguo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770217296; c=relaxed/simple; bh=FLj484Xfg34QCvZtwF77bQTdVnaKCOrdYGJpEuqLG6U=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=L7ry3yQvvYd4ZJIGC2ZwzFAgrUF6qx6NRwSeffmUmTLs8+fIzXa+e4FhWgCm72+t8DlkFuvxXVzDsXLMmsYvuF9zzRih8EUy6YdzT9O6HRzP4V+ST/xn5ClRg2WHog2v3bBGsOT+rJXJ14MmtrEbtosx3YXD8BwQcGzvrU8aibo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=CXxvc6qG; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="CXxvc6qG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7B7C1C116C6; Wed, 4 Feb 2026 15:01:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1770217296; bh=FLj484Xfg34QCvZtwF77bQTdVnaKCOrdYGJpEuqLG6U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CXxvc6qGzg0BNZeg2VZu+XewrEQTpgx3Z2Z/iiSY0utZdALPDAn/U3JxcdCTUDGTq 1R5zFf57fu8I7nKgzdFI8iF/b7ZcVeakgUh8/9y+gjL9AeD+jJCsvQy10W9Yix90rX qfAMYyp/clCp1vBJI2QTH9AJmcqk+t22BSTNcBJ8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jakub Kicinski , Zqiang , Paolo Abeni , Rahul Sharma Subject: [PATCH 5.15 182/206] usbnet: Fix using smp_processor_id() in preemptible code warnings Date: Wed, 4 Feb 2026 15:40:13 +0100 Message-ID: <20260204143904.774143890@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260204143858.193781818@linuxfoundation.org> References: <20260204143858.193781818@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ 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=81f55dfa587ee544baaaa5a359a060512228c1e1 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 Signed-off-by: Greg Kroah-Hartman --- drivers/net/usb/usbnet.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/net/usb/usbnet.c +++ b/drivers/net/usb/usbnet.c @@ -707,6 +707,7 @@ 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) { @@ -715,6 +716,7 @@ void usbnet_resume_rx(struct usbnet *dev } tasklet_schedule(&dev->bh); + local_bh_enable(); netif_dbg(dev, rx_status, dev->net, "paused rx queue disabled, %d skbs requeued\n", num);