From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-186.mta1.migadu.com (out-186.mta1.migadu.com [95.215.58.186]) (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 8B4472853EF for ; Tue, 30 Sep 2025 08:46:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.186 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759222007; cv=none; b=stgM0kpdbm2jmBgSjbn8XyGT+gwFnLnDrhJR8Djy+4N7jSlscOLjmjnoP3RGD/KLau5dUDowJJOxCbnFOPA5A0N4vActVqPXmza+/LCSKL0EaHBXsaogJGJHJleG1DrHwPh0eObJx0Q0tek9r4J4FWsdDIP+6OEoMu8xVYNWk7g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759222007; c=relaxed/simple; bh=kNodwE8ISdOsR62lgF1hpuhR9iqoNPi98sJfxdnumgM=; h=From:To:Cc:Subject:Date:Message-Id; b=s5V1gUCjB6IBg/N9bAclXrWmBdmILsV9ptALaWo+TFsNTE61nK14153AFnx68sC6MLqn4GxvH8Lq7fN6r6bqCJH88hXwBALeviq+AYkpjshk6QjwNhtM0JMLgGlqaq/SKhqUkb9sfP+rXlGrEG4tOlKwlDIaMt0cj50dZMpLgd8= 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=DL2u5X7f; arc=none smtp.client-ip=95.215.58.186 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="DL2u5X7f" 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=1759222001; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc; bh=j5AcYdvJFrn+nCGCLPaED2CyHb1mgyd2csHm8RlZh3k=; b=DL2u5X7f0y2WjRKJPPtgDwkXH3jygPQkflOzbURaKgaKj+y704/p8VoNAgc2LZno+nSEJZ Uka6vYFxpcUVDYhyAFbh9v9mcDtHhk35DBWA6DLNVmqUjLYgOoxNkFpkqhIf7tOcpGMP7g wq6krYDC91EkcpgXsTmsnm6ix8Jb/K4= From: Zqiang To: kuba@kernel.org, horms@kernel.org, davem@davemloft.net, pabeni@redhat.com Cc: qiang.zhang@linux.dev, netdev@vger.kernel.org Subject: [PATCH] usbnet: Fix using smp_processor_id() in preemptible code warnings Date: Tue, 30 Sep 2025 16:46:36 +0800 Message-Id: <20250930084636.5835-1-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 The usbnet_skb_return() can be invoked in preemptible task-context, this commit therefore use get_cpu_ptr/put_cpu_ptr() instead of this_cpu_ptr() to get stats64 pointer. Fixes: 43daa96b166c ("usbnet: Stop RX Q on MTU change") Link: https://lore.kernel.org/all/681607f0.a70a0220.254cdc.001a.GAE@google.com/T/ Signed-off-by: Zqiang --- drivers/net/usb/usbnet.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c index 511c4154cf74..89f79a0bdc43 100644 --- a/drivers/net/usb/usbnet.c +++ b/drivers/net/usb/usbnet.c @@ -328,7 +328,7 @@ static void __usbnet_status_stop_force(struct usbnet *dev) */ void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb) { - struct pcpu_sw_netstats *stats64 = this_cpu_ptr(dev->net->tstats); + struct pcpu_sw_netstats *stats64; unsigned long flags; int status; @@ -341,10 +341,12 @@ void usbnet_skb_return (struct usbnet *dev, struct sk_buff *skb) if (skb->protocol == 0) skb->protocol = eth_type_trans (skb, dev->net); + stats64 = get_cpu_ptr(dev->net->tstats); flags = u64_stats_update_begin_irqsave(&stats64->syncp); u64_stats_inc(&stats64->rx_packets); u64_stats_add(&stats64->rx_bytes, skb->len); u64_stats_update_end_irqrestore(&stats64->syncp, flags); + put_cpu_ptr(stats64); netif_dbg(dev, rx_status, dev->net, "< rx, len %zu, type 0x%x\n", skb->len + sizeof (struct ethhdr), skb->protocol); -- 2.17.1