From nobody Tue Jun 16 10:24:21 2026 Received: from zg8tmtyylji0my4xnjqumte4.icoremail.net (zg8tmtyylji0my4xnjqumte4.icoremail.net [162.243.164.118]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 22FBF34DCCD; Sat, 18 Apr 2026 12:18:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=162.243.164.118 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776514715; cv=none; b=fBHjZuD+x2tRHP4AQAhWcEINBTluWVuEb3K1olSLfRAKGDLN1hO8Cgst1uRnB73eNqCjZr/0jfpOCbn8FRXXIgTObFlTce7IGkSWDwZGEBwsREPElTwxuS94JuHgTWifDcsX0A2m9ZroJLqd5BeX/5RACLPsbX4O3j+khW0YYHA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776514715; c=relaxed/simple; bh=wDzbXZhLh94RRVK+pCs9UkrM63fbj82TLjhru0A71Ro=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=k7EYvA0rCtAljALkAcZJKgav9OsChSfoIjUtgPPNkvoEK7wikPtyQ1rAWUtiyphMmYLPO7GfD6XsJ185Y+DnD9Ykvh7kSKgXuNe41wQJ+IUiH2CvGWEabinREEh35VrLktO2v/VGcOB4Jkq8auf9xc8eps7N2s7Vc2XWQjzndGU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=stu.xidian.edu.cn; spf=pass smtp.mailfrom=stu.xidian.edu.cn; dkim=fail (0-bit key) header.d=stu.xidian.edu.cn header.i=@stu.xidian.edu.cn header.b=0IUMzExT reason="key not found in DNS"; arc=none smtp.client-ip=162.243.164.118 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=stu.xidian.edu.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=stu.xidian.edu.cn Authentication-Results: smtp.subspace.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=stu.xidian.edu.cn header.i=@stu.xidian.edu.cn header.b="0IUMzExT" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=stu.xidian.edu.cn; s=dkim; h=Received:From:To:Cc:Subject:Date: Message-Id:MIME-Version:Content-Transfer-Encoding; bh=TEpmaqV2cr 73O2zRkCteMaRgSagJzIImAOJtTOjMaGE=; b=0IUMzExT3uKWkafGlqieWb7HZX F/32E08vJ2joEIijYZcasmfiaIrKfFOjIqZ3WdsZRVMq69WcSNMtaVTlaL334Iua lKPETqP9wBGcVMPZq/ESXL9Aqr/5EEfP2OXgpjaSvKChfnKyEbt2xb7iC1DLjhlh az+ecsgyLhNZm71is= Received: from wmy.localdomain (unknown [113.200.174.100]) by hzbj-edu-front-4.icoremail.net (Coremail) with SMTP id BrQMCkBW_rl+duNpzfihAQ--.24054S2; Sat, 18 Apr 2026 20:18:16 +0800 (CST) From: Mingyu Wang <25181214217@stu.xidian.edu.cn> To: andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com Cc: tglx@kernel.org, mingo@kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Mingyu Wang <25181214217@stu.xidian.edu.cn> Subject: [PATCH] net: hamachi: fix divide by zero in hamachi_init_one Date: Sat, 18 Apr 2026 20:18:04 +0800 Message-Id: <20260418121804.149171-1-25181214217@stu.xidian.edu.cn> 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: BrQMCkBW_rl+duNpzfihAQ--.24054S2 X-Coremail-Antispam: 1UD129KBjvJXoW7try8uFW5tF1xuF1kCrWfXwb_yoW8uFy8pF WYk34vyw4DKwn0q3Z7trWxAFn8uay3t3y5uF95Jw1a93s8CFyrtr15KFWj9a43CFWrCw40 yrWvyFy7uFn8tw7anT9S1TB71UUUUUDqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUPF14x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26r1j6r1xM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r4j 6F4UM28EF7xvwVC2z280aVAFwI0_Gr1j6F4UJwA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_Gr 1j6F4UJwAac4AC62xK8xCEY4vEwIxC4wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40E FcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWUXVWUAwAv7VC2z280aVAFwI0_Gr 0_Cr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7VAKI48JM4x0x7Aq67IIx4CEVc8v x2IErcIFxwACI402YVCY1x02628vn2kIc2xKxwCY1x0262kKe7AKxVWUtVW8ZwCY02Avz4 vE14v_Xr1l42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG 67AKxVWUJVWUGwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r1q6r43MI IYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_Jr0_JF4lIxAIcVC0I7IYx2IY6xkF7I0E 14v26r4j6F4UMIIF0xvE42xK8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJV W8JwCI42IY6I8E87Iv6xkF7I0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjfU0yCJ DUUUU X-CM-SenderInfo: qsvrmiqsrujiux6v33wo0lvxldqovvfxof0/1tbiAgUHEWniTmNg3AAEsP Content-Type: text/plain; charset="utf-8" During the hardware initialization phase in hamachi_init_one(), the driver reads the PCIClkMeas register to calculate the PCI bus frequency. The current code attempts to prevent a divide-by-zero error using a ternary operator: `i ? 2000/(i&0x7f) : 0`. However, this check is flawed. The highe= st bit of `i` (0x80) acts as a ready flag. If unreliable hardware or a malicio= us virtual device returns a value where the ready bit is set but the lower 7 b= its are zero (e.g., 0x80), the condition `i` evaluates to true, but `(i & 0x7f)` evaluates to 0. This results in a fatal divide-by-zero exception. This bug was discovered during an automated virtual device fuzzing campaign testing the hardware-software trust boundary. When the hardware returns 0x8= 0, it bypassed the readiness while-loop but triggered the divide error. In our tests, this panic interrupted the module loading process, further triggering a KASAN slab-out-of-bounds in the module error path, and ultimately leading to a multi-core soft lockup and RCU stall. This patch fixes the issue by explicitly checking the divisor `(i & 0x7f)` instead of the entire register value `i` before performing the division. Signed-off-by: Mingyu Wang <25181214217@stu.xidian.edu.cn> --- drivers/net/ethernet/packetengines/hamachi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/packetengines/hamachi.c b/drivers/net/eth= ernet/packetengines/hamachi.c index b0de7e9f12a5..1d7206dd18fd 100644 --- a/drivers/net/ethernet/packetengines/hamachi.c +++ b/drivers/net/ethernet/packetengines/hamachi.c @@ -748,7 +748,7 @@ static int hamachi_init_one(struct pci_dev *pdev, printk(KERN_INFO "%s: %d-bit %d Mhz PCI bus (%d), Virtual Jumpers " "%2.2x, LPA %4.4x.\n", dev->name, readw(ioaddr + MiscStatus) & 1 ? 64 : 32, - i ? 2000/(i&0x7f) : 0, i&0x7f, (int)readb(ioaddr + VirtualJumpers), + (i & 0x7f) ? 2000 / (i & 0x7f) : 0, i & 0x7f, (int)readb(ioaddr + Vir= tualJumpers), readw(ioaddr + ANLinkPartnerAbility)); =20 if (chip_tbl[hmp->chip_id].flags & CanHaveMII) { --=20 2.34.1