From nobody Wed Feb 11 05:10:58 2026 Received: from canpmsgout07.his.huawei.com (canpmsgout07.his.huawei.com [113.46.200.222]) (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 E87A53491E1; Tue, 16 Dec 2025 08:13:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=113.46.200.222 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765872803; cv=none; b=ayarx8aR/46F2I+LoALWO2sClqwef28DEMK89QAMiUOw7vn7RgtiUCosonnkfYP6EgxCp0JDn9kqPb0jxUiHhvLDOKac0jjpdowa6PNidqC+9ZkesTNSg2XjsI3knw56wQHwnvynYchjoQjnSFu9OEArpQ6iSm7PTqiaTIabhac= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1765872803; c=relaxed/simple; bh=xl3Lvk6DsS/4aN4YNkfzslgnFtRwt/M8WdQ2kfOHli4=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=APL1eX45Nx7wvP31eKqDqKWva1vgBb6a15x+h2dI73Z5WqQ4dJph/df7aFWevqWuAZrbUsKXsvsW0VnkXsal14DCeqgym9Gnu0KeJZ/A30pwgnV9SvuT+JFESw6O4vjHDTqjnHS6Exm9c94hQVEi2N032isMK9C3SlyoXJZyKWg= 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=xQ9kcjGK; arc=none smtp.client-ip=113.46.200.222 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="xQ9kcjGK" dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=OeYwOcalkq3X/qIjdTsgXrAzZ7kaVzZIJdapxCDLH0c=; b=xQ9kcjGKMvWx2DdJMTh4U6pyUPKHTePf+WZoz4pZOR13QychGOQceFL9tv/NOJUk6pZUtd437 1tm+qlFSsv1kud3i58UXvd1P/ZHv3f7GahETAJYcL4SNgoJkoCE6S5Kzx0MIwtf+W4lVphwMAyX hA34xV/yidzOwE5Rwp/xDaU= Received: from mail.maildlp.com (unknown [172.19.88.214]) by canpmsgout07.his.huawei.com (SkyGuard) with ESMTPS id 4dVqPz0YKqzLlWD; Tue, 16 Dec 2025 16:11:19 +0800 (CST) Received: from kwepemr500012.china.huawei.com (unknown [7.202.195.23]) by mail.maildlp.com (Postfix) with ESMTPS id B9C071A016C; Tue, 16 Dec 2025 16:13:18 +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; Tue, 16 Dec 2025 16:13:18 +0800 From: Ziming Du To: CC: , , , , , , Subject: [PATCH 3/3] PCI: Prevent overflow in proc_bus_pci_write() Date: Tue, 16 Dec 2025 16:39:12 +0800 Message-ID: <20251216083912.758219-4-duziming2@huawei.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20251216083912.758219-1-duziming2@huawei.com> References: <20251216083912.758219-1-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" When the value of ppos over the INT_MAX, the pos will be set a negtive value which will be pass to get_user() or pci_user_write_config_dword(). And unexpected behavior such as a softlock happens: watchdog: BUG: soft lockup - CPU#0 stuck for 130s! [syz.3.109:3444] Modules linked in: CPU: 0 PID: 3444 Comm: syz.3.109 Not tainted 6.6.0+ #33 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-g= a6ed6b701f0a-prebuilt.qemu.org 04/01/2014 RIP: 0010:_raw_spin_unlock_irq+0x17/0x30 Code: cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa= 0f 1f 44 00 00 e8 52 12 00 00 90 fb 65 ff 0d b1 a1 86 6d <74> 05 e9 42 52 = 00 00 0f 1f 44 00 00 c3 cc cc cc cc 0f 1f 84 00 00 RSP: 0018:ffff88816851fb50 EFLAGS: 00000246 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff927daf9b RDX: 0000000000000cfc RSI: 0000000000000046 RDI: ffffffff9a7c7400 RBP: 00000000818bb9dc R08: 0000000000000001 R09: ffffed102d0a3f59 R10: 0000000000000003 R11: 0000000000000000 R12: 0000000000000000 R13: ffff888102220000 R14: ffffffff926d3b10 R15: 00000000210bbb5f FS: 00007ff2d4e56640(0000) GS:ffff8881f5c00000(0000) knlGS:00000000000000= 00 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000210bbb5b CR3: 0000000147374002 CR4: 0000000000772ef0 PKRU: 00000000 Call Trace: pci_user_write_config_dword+0x126/0x1f0 ? __get_user_nocheck_8+0x20/0x20 proc_bus_pci_write+0x273/0x470 proc_reg_write+0x1b6/0x280 do_iter_write+0x48e/0x790 ? import_iovec+0x47/0x90 vfs_writev+0x125/0x4a0 ? futex_wake+0xed/0x500 ? __pfx_vfs_writev+0x10/0x10 ? userfaultfd_ioctl+0x131/0x1ae0 ? userfaultfd_ioctl+0x131/0x1ae0 ? do_futex+0x17e/0x220 ? __pfx_do_futex+0x10/0x10 ? __fget_files+0x193/0x2b0 __x64_sys_pwritev+0x1e2/0x2a0 ? __pfx___x64_sys_pwritev+0x10/0x10 do_syscall_64+0x59/0x110 entry_SYSCALL_64_after_hwframe+0x78/0xe2 Fix this by use unsigned int 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..dbec1d4209c9 100644 --- a/drivers/pci/proc.c +++ b/drivers/pci/proc.c @@ -113,7 +113,7 @@ static ssize_t proc_bus_pci_write(struct file *file, co= nst char __user *buf, { struct inode *ino =3D file_inode(file); struct pci_dev *dev =3D pde_data(ino); - int pos =3D *ppos; + unsigned int pos =3D *ppos; int size =3D dev->cfg_size; int cnt, ret; =20 --=20 2.43.0