linux-kernel - 6.17 crashes in ipv6 code when booted fips=1 [was: [GIT PULL] Crypto Update for 6.17]

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: <1a71398e-637f-4aa5-b4c6-0d3502a62a0c@kernel.org>
Date: Thu, 2 Oct 2025 12:57:11 +0200
From: Jiri Slaby <jirislaby@...nel.org>
To: Herbert Xu <herbert@...dor.apana.org.au>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>,
 "David S. Miller" <davem@...emloft.net>,
 Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
 Linux Crypto Mailing List <linux-crypto@...r.kernel.org>,
 Vegard Nossum <vegard.nossum@...cle.com>, netdev@...r.kernel.org,
 Eric Biggers <ebiggers@...nel.org>, Jakub Kicinski <kuba@...nel.org>
Subject: 6.17 crashes in ipv6 code when booted fips=1 [was: [GIT PULL] Crypto
 Update for 6.17]

On 02. 10. 25, 12:13, Jiri Slaby wrote:
> On 02. 10. 25, 12:05, Jiri Slaby wrote:
>> On 02. 10. 25, 11:30, Herbert Xu wrote:
>>> On Thu, Oct 02, 2025 at 10:10:41AM +0200, Jiri Slaby wrote:
>>>> On 29. 07. 25, 13:07, Herbert Xu wrote:
>>>>> Vegard Nossum (1):
>>>>>         crypto: testmgr - desupport SHA-1 for FIPS 140
>>>>
>>>> Booting 6.17 with fips=1 crashes with this commit -- see below.
>>>>
>>>> The crash is different being on 6.17 (below) and on the commit --
>>>> 9d50a25eeb05c45fef46120f4527885a14c84fb2.
>>>>
>>>> 6.17 minus that one makes it work again.
>>>>
>>>> Any ideas?
>>>
>>> The purpose of the above commit is to remove the SHA1 algorithm
>>> if you boot with fips=1.  As net/ipv6/seg6_hmac.c depends on the
>>> sha1 algorithm, it will obviously fail if SHA1 isn't there.
>>
>> Ok, but I don't immediately see what is one supposed to do to boot 
>> 6.17 distro (openSUSE) kernel with fips=1 then?
> 
> Now I do, in the context you write, I see inet6_init()'s fail path is 
> broken. The two backtraces show:
> [    2.381371][    T1]  ip6_mr_cleanup+0x43/0x50
> [    2.382321][    T1]  inet6_init+0x365/0x3d0
> 
> and
> 
> [    2.420857][    T1]  proto_unregister+0x93/0x100
> [    2.420857][    T1]  inet6_init+0x3a2/0x3d0
> 
> I am looking what exactly, but this is rather for netdev@

More functions from the fail path are not ready to unroll and resurrect 
from the failure.

Anyway, cherry-picking this -next commit onto 6.17 works as well (the 
code uses now crypto_lib's sha1, not crypto's):
commit 095928e7d80186c524013a5b5d54889fa2ec1eaa
Author: Eric Biggers <ebiggers@...nel.org>
Date:   Sat Aug 23 21:36:43 2025 -0400

     ipv6: sr: Use HMAC-SHA1 and HMAC-SHA256 library functions

I don't know what to do next -- should it be put into 6.17 stable later 
and we are done?

thanks,
-- 
js
suse labs