Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752029AbdIEOpl (ORCPT ); Tue, 5 Sep 2017 10:45:41 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40758 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751875AbdIEOow (ORCPT ); Tue, 5 Sep 2017 10:44:52 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 9737C267F8 Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=joe.lawrence@redhat.com From: Joe Lawrence To: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Cc: Alexander Viro , "Luis R. Rodriguez" , Kees Cook , Mikulas Patocka , Michael Kerrisk Subject: [PATCH RFC 3/3] pipe: match pipe_max_size data type with procfs Date: Tue, 5 Sep 2017 10:44:36 -0400 Message-Id: <1504622676-2992-4-git-send-email-joe.lawrence@redhat.com> In-Reply-To: <1504622676-2992-1-git-send-email-joe.lawrence@redhat.com> References: <1504622676-2992-1-git-send-email-joe.lawrence@redhat.com> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Tue, 05 Sep 2017 14:44:52 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2126 Lines: 70 pipe_max_size is defined as an unsigned int: unsigned int pipe_max_size = 1048576; but its procfs/sysctl representation is an integer: static struct ctl_table fs_table[] = { ... { .procname = "pipe-max-size", .data = &pipe_max_size, .maxlen = sizeof(int), .mode = 0644, .proc_handler = &pipe_proc_fn, .extra1 = &pipe_min_size, }, ... that is signed: int pipe_proc_fn(struct ctl_table *table, int write, void __user *buf, size_t *lenp, loff_t *ppos) { ... ret = proc_dointvec_minmax(table, write, buf, lenp, ppos) This leads to signed results via procfs for large values of pipe_max_size: % echo 2147483647 >/proc/sys/fs/pipe-max-size % cat /proc/sys/fs/pipe-max-size -2147483648 Use unsigned operations on this variable to avoid such negative values. Reported-by: Mikulas Patocka Signed-off-by: Joe Lawrence --- fs/pipe.c | 2 +- kernel/sysctl.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/pipe.c b/fs/pipe.c index 33bb11b0d78e..3b10d39cc5d1 100644 --- a/fs/pipe.c +++ b/fs/pipe.c @@ -1147,7 +1147,7 @@ int pipe_proc_fn(struct ctl_table *table, int write, void __user *buf, mutex_lock(&pipe_max_mutex); orig_pipe_max_size = pipe_max_size; - ret = proc_dointvec_minmax(table, write, buf, lenp, ppos); + ret = proc_douintvec_minmax(table, write, buf, lenp, ppos); if (ret < 0 || !write) { mutex_unlock(&pipe_max_mutex); return ret; diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 6648fbbb8157..c976719bf37a 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1825,7 +1825,7 @@ static int sysrq_sysctl_handler(struct ctl_table *table, int write, { .procname = "pipe-max-size", .data = &pipe_max_size, - .maxlen = sizeof(int), + .maxlen = sizeof(pipe_max_size), .mode = 0644, .proc_handler = &pipe_proc_fn, .extra1 = &pipe_min_size, -- 1.8.3.1