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From: James Bottomley <James.Bottomley@HansenPartnership.com>
To: Linus Torvalds <torvalds@linux-foundation.org>,
	ebiggers@kernel.org,
	James Morris James Morris <jmorris@namei.org>,
	Mimi Zohar <zohar@linux.vnet.ibm.com>,
	Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
	Peter Huewe <peterhuewe@gmx.de>
Cc: David Howells <dhowells@redhat.com>,
	keyrings@vger.kernel.org,
	Linux List Kernel Mailing <linux-kernel@vger.kernel.org>,
	syzkaller-bugs@googlegroups.com
Subject: Re: [PATCH RESEND] KEYS: fix parsing invalid pkey info string
Date: Mon, 17 Dec 2018 19:51:00 +0000	[thread overview]
Message-ID: <1545076260.2878.15.camel@HansenPartnership.com> (raw)
In-Reply-To: <CAHk-=wgGYebCEE-M-6Dnbn5MpC8BD8SLjgw8iPGrgy8zETrdJg@mail.gmail.com>

On Mon, 2018-12-17 at 11:39 -0800, Linus Torvalds wrote:
> On Mon, Dec 17, 2018 at 11:06 AM Linus Torvalds
> <torvalds@linux-foundation.org> wrote:
> > 
> > Honestly, for being about "security", all of this code seems to be
> > doing some really questionable things with all those Opt_xyz enums.
> 
> Yeah, at least security/keys/trusted.c ends up mixing that enum and
> just using "int" completely randomly, and you have datablob_parse()
> returning either a negative integer _or_ an "Opt_xyz" value, so
> having Opt_err be -1 is doubly confusing there (it would also be "-
> EPERM" depending on how you treat it).
> 
> There doesn't seem to be any _actual_ confusion (because Opt_err is
> always turned into an actual real error code), but it's  just another
> sign of "those enums should not be negative".
> 
> So on the whole, I think that the "Opt_err = -1" is a serious
> mistake, but at least for now, ima_policy.c clearly has (bogus) code
> that relies on it.
> 
> But the two cases that use "test_and_set_bit()" do not seem to have
> any reason to use that -1 enum, so while we can't do the "just remove
> -1" in general, I do think the proper fix is to just do it for those
> two files.
> 
> Eric, mind testing a patch like that? Untested patch attached just
> for completeness..

If this is to replace Eric's patch, didn't you want to set token_mask
to (1<<Opt_err)?

James

WARNING: multiple messages have this Message-ID (diff)
From: James Bottomley <James.Bottomley@HansenPartnership.com>
To: Linus Torvalds <torvalds@linux-foundation.org>,
	ebiggers@kernel.org,
	James Morris James Morris <jmorris@namei.org>,
	Mimi Zohar <zohar@linux.vnet.ibm.com>,
	Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
	Peter Huewe <peterhuewe@gmx.de>
Cc: David Howells <dhowells@redhat.com>,
	keyrings@vger.kernel.org,
	Linux List Kernel Mailing <linux-kernel@vger.kernel.org>,
	syzkaller-bugs@googlegroups.com
Subject: Re: [PATCH RESEND] KEYS: fix parsing invalid pkey info string
Date: Mon, 17 Dec 2018 11:51:00 -0800	[thread overview]
Message-ID: <1545076260.2878.15.camel@HansenPartnership.com> (raw)
In-Reply-To: <CAHk-=wgGYebCEE-M-6Dnbn5MpC8BD8SLjgw8iPGrgy8zETrdJg@mail.gmail.com>

On Mon, 2018-12-17 at 11:39 -0800, Linus Torvalds wrote:
> On Mon, Dec 17, 2018 at 11:06 AM Linus Torvalds
> <torvalds@linux-foundation.org> wrote:
> > 
> > Honestly, for being about "security", all of this code seems to be
> > doing some really questionable things with all those Opt_xyz enums.
> 
> Yeah, at least security/keys/trusted.c ends up mixing that enum and
> just using "int" completely randomly, and you have datablob_parse()
> returning either a negative integer _or_ an "Opt_xyz" value, so
> having Opt_err be -1 is doubly confusing there (it would also be "-
> EPERM" depending on how you treat it).
> 
> There doesn't seem to be any _actual_ confusion (because Opt_err is
> always turned into an actual real error code), but it's  just another
> sign of "those enums should not be negative".
> 
> So on the whole, I think that the "Opt_err = -1" is a serious
> mistake, but at least for now, ima_policy.c clearly has (bogus) code
> that relies on it.
> 
> But the two cases that use "test_and_set_bit()" do not seem to have
> any reason to use that -1 enum, so while we can't do the "just remove
> -1" in general, I do think the proper fix is to just do it for those
> two files.
> 
> Eric, mind testing a patch like that? Untested patch attached just
> for completeness..

If this is to replace Eric's patch, didn't you want to set token_mask
to (1<<Opt_err)?

James


  reply	other threads:[~2018-12-17 19:51 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-03 15:48 general protection fault in keyctl_pkey_params_get syzbot
2018-11-03 15:48 ` syzbot
2018-11-03 17:30 ` [PATCH] KEYS: fix parsing invalid pkey info string Eric Biggers
2018-11-03 17:30   ` Eric Biggers
2018-11-28 23:20   ` Eric Biggers
2018-11-28 23:20     ` Eric Biggers
2018-12-06 18:26     ` Eric Biggers
2018-12-06 18:26       ` Eric Biggers
2018-12-17 18:12     ` [PATCH RESEND] " Eric Biggers
2018-12-17 18:12       ` Eric Biggers
2018-12-17 18:43       ` Linus Torvalds
2018-12-17 18:43         ` Linus Torvalds
2018-12-17 18:49         ` Linus Torvalds
2018-12-17 18:49           ` Linus Torvalds
2018-12-17 19:06           ` Linus Torvalds
2018-12-17 19:06             ` Linus Torvalds
2018-12-17 19:39             ` Linus Torvalds
2018-12-17 19:39               ` Linus Torvalds
2018-12-17 19:51               ` James Bottomley [this message]
2018-12-17 19:51                 ` James Bottomley
2018-12-17 20:02                 ` Linus Torvalds
2018-12-17 20:02                   ` Linus Torvalds
2018-12-17 20:29                   ` Mimi Zohar
2018-12-17 20:29                     ` Mimi Zohar
2018-12-18  0:44                   ` James Bottomley
2018-12-18  0:44                     ` James Bottomley
2018-12-31 22:45                   ` Eric Biggers
2018-12-31 22:45                     ` Eric Biggers
2019-01-01 21:08                     ` Linus Torvalds
2019-01-01 21:08                       ` Linus Torvalds
2018-12-17 20:21             ` Mimi Zohar
2018-12-17 20:21               ` Mimi Zohar
2018-12-17 20:31               ` Linus Torvalds
2018-12-17 20:31                 ` Linus Torvalds
2018-12-18 12:34         ` Dmitry Vyukov
2018-12-18 12:34           ` Dmitry Vyukov

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