From nobody Tue Feb 10 01:58:46 2026 Received: from canpmsgout02.his.huawei.com (canpmsgout02.his.huawei.com [113.46.200.217]) (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 4BD98314A8A; Wed, 24 Dec 2025 09:01:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=113.46.200.217 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766566909; cv=none; b=sE2N/jX7o7hEVgHVbljpqeOkOOwovfAQr8TYB0TkQ9ujGTOyfEJ/5XOSuEoKGIZvl3oSoAbsDiv9kHV/vA6gnWFbFzTasZ+C7MyDVNgKQpvZHgwKf6rgbX5izdrUWnf2fFsk7D5CWOcvzvc8Ii3oGZ86akMaCAJM/L1SM86YCWY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1766566909; c=relaxed/simple; bh=sO7UHcb/eUGLpdl+ntAUbze0WfDTxTM88mnwukPDwFM=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=ljgVICICzMPaaYf/4Z3fnytFEBP41LqypT9x3VPALRL6PfqLbDs6BBg08qU4plUuESaDVXy7hCWAA4lZQRtRU49VPPZNTFBtFvaAKXJJ4vwVEbgf0fGksA99UztknEYEJ4pG1YJgB6RX4F+VnHkRbQOIOS1mAGwHOGUAcbC894E= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b=oIu51P+u; arc=none smtp.client-ip=113.46.200.217 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b="oIu51P+u" dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=4FTwMVa6Sjk6xK1eTvo9FnDHO5W9eKanW66S/6WEpzU=; b=oIu51P+uy7aHuHB1sVb/T24N9aVdJ1vqHv+g8Ks6aR1NWcFXBeSNl+4daRM4FPXUIMHC7HSz/ hR5Wpe3mKGUhOCUQ3VPvKZpLIBSwV/gP0oCwMFHvWg+GAibXc4IL8D8xc7D+QZnBuvgJlIll1e7 sHF63tC/DQHG7IYzJDI9/6w= Received: from mail.maildlp.com (unknown [172.19.162.144]) by canpmsgout02.his.huawei.com (SkyGuard) with ESMTPS id 4dbm4q3PX7zcZxm; Wed, 24 Dec 2025 16:58:35 +0800 (CST) Received: from kwepemr500012.china.huawei.com (unknown [7.202.195.23]) by mail.maildlp.com (Postfix) with ESMTPS id A685D40538; Wed, 24 Dec 2025 17:01:41 +0800 (CST) Received: from localhost.localdomain (10.50.85.180) by kwepemr500012.china.huawei.com (7.202.195.23) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Wed, 24 Dec 2025 17:01:41 +0800 From: Ziming Du To: , , , CC: , , , Subject: [PATCH v2 2/3] PCI: Prevent overflow in proc_bus_pci_write() Date: Wed, 24 Dec 2025 17:27:18 +0800 Message-ID: <20251224092721.2034529-3-duziming2@huawei.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20251224092721.2034529-1-duziming2@huawei.com> References: <20251224092721.2034529-1-duziming2@huawei.com> 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-ClientProxiedBy: kwepems200002.china.huawei.com (7.221.188.68) To kwepemr500012.china.huawei.com (7.202.195.23) Content-Type: text/plain; charset="utf-8" From: Yongqiang Liu When the value of ppos over the INT_MAX, the pos is over set to a negtive value which will be passed to get_user() or pci_user_write_config_dword(). Unexpected behavior such as a softlock will happen as follows: watchdog: BUG: soft lockup - CPU#0 stuck for 130s! [syz.3.109:3444] RIP: 0010:_raw_spin_unlock_irq+0x17/0x30 Call Trace: pci_user_write_config_dword+0x126/0x1f0 proc_bus_pci_write+0x273/0x470 proc_reg_write+0x1b6/0x280 do_iter_write+0x48e/0x790 vfs_writev+0x125/0x4a0 __x64_sys_pwritev+0x1e2/0x2a0 do_syscall_64+0x59/0x110 entry_SYSCALL_64_after_hwframe+0x78/0xe2 Fix this by add check for the pos. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Yongqiang Liu Signed-off-by: Ziming Du --- drivers/pci/proc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/pci/proc.c b/drivers/pci/proc.c index 9348a0fb8084..200d42feafd8 100644 --- a/drivers/pci/proc.c +++ b/drivers/pci/proc.c @@ -121,7 +121,7 @@ static ssize_t proc_bus_pci_write(struct file *file, co= nst char __user *buf, if (ret) return ret; =20 - if (pos >=3D size) + if (pos >=3D size || pos < 0) return 0; if (nbytes >=3D size) nbytes =3D size; --=20 2.43.0