linux-kernel - Re: [PATCH] kernel/sysctl.c: If "count" including the terminating byte '\0' the write system call should retrun success.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <FBEE5CF8-6B74-4060-9553-1D42BDAD15FA@xmission.com>
Date:	Mon, 24 Aug 2015 05:27:35 -0700
From:	"Eric W. Biederman" <ebiederm@...ssion.com>
To:	Sean Fu <fxinrong@...il.com>,
	Andrey Ryabinin <ryabinin.a.a@...il.com>,
	Ulrich Obergfell <uobergfe@...hat.com>,
	"Steven Rostedt (Red Hat)" <rostedt@...dmis.org>,
	Prarit Bhargava <prarit@...hat.com>,
	Eric B Munson <emunson@...mai.com>,
	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>,
	Johannes Weiner <hannes@...xchg.org>
CC:	Andrew Morton <akpm@...ux-foundation.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Don Zickus <dzickus@...hat.com>,
	Heinrich Schuchardt <xypron.glpk@....de>,
	David Rientjes <rientjes@...gle.com>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] kernel/sysctl.c: If "count" including the terminating byte '\0' the write system call should retrun success.



On August 24, 2015 1:56:13 AM PDT, Sean Fu <fxinrong@...il.com> wrote:
>when the input argument "count" including the terminating byte "\0",
>The write system call return EINVAL on proc file.
>But it return success on regular file.

Nonsense.  It will write the '\0' to a regular file because it is just data.

Integers in proc are more than data.

So I see no justification for this change.


Eric

>E.g. Writting two bytes ("1\0") to
>"/proc/sys/net/ipv4/conf/eth0/rp_filter".
>write(fd, "1\0", 2) return EINVAL.
>
>Signed-off-by: Sean Fu <fxinrong@...il.com>
>---
> kernel/sysctl.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
>diff --git a/kernel/sysctl.c b/kernel/sysctl.c
>index 19b62b5..c2b0594 100644
>--- a/kernel/sysctl.c
>+++ b/kernel/sysctl.c
>@@ -2004,7 +2004,7 @@ static int do_proc_dointvec_conv(bool *negp,
>unsigned long *lvalp,
>        return 0;
> }
>
>-static const char proc_wspace_sep[] = { ' ', '\t', '\n' };
>+static const char proc_wspace_sep[] = { ' ', '\t', '\n', '\0' };
>
> static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
>                  int write, void __user *buffer,

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/