From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AB8JxZp210kt2/1RNlsBFI5Njmd8A2tjnQ8ucahmqDqKXL0RwIaH2V9c0BBrKEddytrWM2v4CdDV ARC-Seal: i=1; a=rsa-sha256; t=1525225510; cv=none; d=google.com; s=arc-20160816; b=XIA2CZ24kvIV3cbLgG5KNJFBO1r79P6xZ/K7R0h4oCZAK4OscHo9dDY1yUL8FZlRZZ T+YqxGvj3MFWcQcfmdwkAHQTu6P1wwSpgxSFruhP7kx60WBL4ueIlulUD0sUW9aRMVzy hyIHFrT3UmQOwQfmTeFcNUFNsyNSR2a8VHQiyHEUVX/k+MYv+hq0BopE4rUZhWDjgU7A mvmTm/swp7sgjjWM/hwRPlMvQNQ9aF8vYBAnw2zQMZa8wznRueOdTFqPr4WBdANxYwiC sc/cTki51Tqd5kpoHkAdX9VS6+o7GKSzgQ40cSTnEzbLWttEAR8ZARn7mATOaddbltQ3 QqoA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:arc-authentication-results; bh=coVzBXHODu/BJpHOTdQoD2dy+AAqCMz6Yz+juvwoHkI=; b=n+rU+Lxt8cWdB5YUs39yigI4Kjhk5ruAni5H8UYAPcpck5roOeN6Kebd+9FJ+V68ux xQYscQhzQur/ZF3LLY+3MoK9jEESnz2uDOejX/sUnTz8ajDNkw8PjbKWcWE+1upvbUUz BxIGUi31iqG44uWlfy7thpR7I3N+I8oC3ebwtypF2myIfhRAZJSpJzDjiOUf/7SmbIQR 5OmWswIHAcGONK/9+a74AODMBaOJnALL5g9XbMm2Czyicn1/+w5Dh4Ra25Yl2plOSO2Y MZwKbrcEFTPwKbPAPbUNnJ0LDjqUZ6bDg+0uCYOywcZdLn0/bAJnSFV0OmqdsTyPJwx3 VfJw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of srs0=dzsu=hv=goodmis.org=rostedt@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=DzSU=HV=goodmis.org=rostedt@kernel.org Authentication-Results: mx.google.com; spf=pass (google.com: domain of srs0=dzsu=hv=goodmis.org=rostedt@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=SRS0=DzSU=HV=goodmis.org=rostedt@kernel.org Date: Tue, 1 May 2018 21:45:07 -0400 From: Steven Rostedt To: tcharding Cc: Linus Torvalds , Linux Kernel Mailing List , Randy Dunlap , Kees Cook , Anna-Maria Gleixner , Andrew Morton , Theodore Ts'o , Greg Kroah-Hartman , Arnd Bergmann Subject: Re: [PATCH 3/3] vsprintf: Add use-early-random-bytes cmd line option Message-ID: <20180501214507.22138131@vmware.local.home> In-Reply-To: <20180502012758.GD3791@eros> References: <1525217620-4107-1-git-send-email-me@tobin.cc> <1525217620-4107-4-git-send-email-me@tobin.cc> <20180502012758.GD3791@eros> X-Mailer: Claws Mail 3.15.1 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1599306645428721863?= X-GMAIL-MSGID: =?utf-8?q?1599314864549834987?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Wed, 2 May 2018 11:27:58 +1000 tcharding wrote: > On Wed, May 02, 2018 at 01:02:34AM +0000, Linus Torvalds wrote: > > On Tue, May 1, 2018 at 4:34 PM Tobin C. Harding wrote: > > > > > > > This option should NOT be enabled on production kernels. > > > > I think with your fixes to get_random_bytes_arch(), it's perfectly fine to > > use on production kernels (and doesn't even need a kernel command line > > option). > > > > It was only with the "use weak crypto" (that get_random_bytes_arch() used > > to fall back on) that it was a problem. That fixed "verify that > > get_random_bytes_arch() really uses hw crypto" is certainly not weak crypto. Except for where hardware vendors control what random bytes you actually get ;-) > > Ok, I'll wait to see if anyone with a more paranoid disposition adds to > this otherwise will implement as suggested. I still test on a lot of old boxes (my old workstations turn into my test boxes). I haven't tried to see which machines have RDRAND support. But regardless, can we still have a command line option that forces early randomization even if RDRAND isn't supported? -- Steve