linux-kernel - Re: [PATCH v4] Added PR_SET_PROCTITLE

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: <20091103230548.0B45.A69D9226@jp.fujitsu.com>
Date:	Tue, 3 Nov 2009 23:07:47 +0900 (JST)
From:	KOSAKI Motohiro <kosaki.motohiro@...fujitsu.com>
To:	Americo Wang <xiyou.wangcong@...il.com>
Cc:	kosaki.motohiro@...fujitsu.com, Timo Sirainen <tss@....fi>,
	Bryan Donlan <bdonlan@...il.com>,
	Ulrich Drepper <drepper@...hat.com>,
	LKML <linux-kernel@...r.kernel.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	linux-api@...r.kernel.org
Subject: Re: [PATCH v4] Added PR_SET_PROCTITLE_AREA option for prctl()

> >+		case PR_SET_PROCTITLE_AREA: {
> >+			struct mm_struct *mm = current->mm;
> >+			unsigned long addr = arg2;
> >+			unsigned long len = arg3;
> >+			unsigned long end = arg2 + arg3;
> >+
> >+			if (len > PAGE_SIZE)
> >+				return -EINVAL;
> >+
> >+			if (addr >= end)
> >+				return -EINVAL;
> >+
> >+			if (!access_ok(VERIFY_READ, addr, len))
> >+				return -EFAULT;
> >+
> >+			mutex_lock(&mm->arg_lock);
> >+			mm->arg_start = addr;
> 
> Is this safe? You're assigning a user-space pointer to kernel space...
> Don't we need copy_from_user()?

mm->arg_start, arg_end are defined so.
Please see current implementation. 


> >+			mm->arg_end = addr + len;
> 
> Since you already have 'end', no need to caculate this again. :)

Good catch :)


--
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/