From: Petr Pavlu <petr.pavlu@suse.com>
To: David Howells <dhowells@redhat.com>,
David Woodhouse <dwmw2@infradead.org>,
Luis Chamberlain <mcgrof@kernel.org>,
Petr Pavlu <petr.pavlu@suse.com>,
Daniel Gomez <da.gomez@kernel.org>,
Sami Tolvanen <samitolvanen@google.com>,
Aaron Tomlin <atomlin@atomlin.com>
Cc: keyrings@vger.kernel.org, linux-modules@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH 1/2] module: Remove SHA-1 support for module signing
Date: Tue, 11 Nov 2025 16:48:31 +0100 [thread overview]
Message-ID: <20251111154923.978181-2-petr.pavlu@suse.com> (raw)
In-Reply-To: <20251111154923.978181-1-petr.pavlu@suse.com>
SHA-1 is considered deprecated and insecure due to vulnerabilities that can
lead to hash collisions. Most distributions have already been using SHA-2
for module signing because of this. The default was also changed last year
from SHA-1 to SHA-512 in commit f3b93547b91a ("module: sign with sha512
instead of sha1 by default"). This was not reported to cause any issues.
Therefore, it now seems to be a good time to remove SHA-1 support for
module signing.
Commit 16ab7cb5825f ("crypto: pkcs7 - remove sha1 support") previously
removed support for reading PKCS#7/CMS signed with SHA-1, along with the
ability to use SHA-1 for module signing. This change broke iwd and was
subsequently completely reverted in commit 203a6763ab69 ("Revert "crypto:
pkcs7 - remove sha1 support""). However, dropping only the support for
using SHA-1 for module signing is unrelated and can still be done
separately.
Note that this change only removes support for new modules to be SHA-1
signed, but already signed modules can still be loaded.
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
---
kernel/module/Kconfig | 5 -----
1 file changed, 5 deletions(-)
diff --git a/kernel/module/Kconfig b/kernel/module/Kconfig
index 2a1beebf1d37..be74917802ad 100644
--- a/kernel/module/Kconfig
+++ b/kernel/module/Kconfig
@@ -299,10 +299,6 @@ choice
possible to load a signed module containing the algorithm to check
the signature on that module.
-config MODULE_SIG_SHA1
- bool "SHA-1"
- select CRYPTO_SHA1
-
config MODULE_SIG_SHA256
bool "SHA-256"
select CRYPTO_SHA256
@@ -332,7 +328,6 @@ endchoice
config MODULE_SIG_HASH
string
depends on MODULE_SIG || IMA_APPRAISE_MODSIG
- default "sha1" if MODULE_SIG_SHA1
default "sha256" if MODULE_SIG_SHA256
default "sha384" if MODULE_SIG_SHA384
default "sha512" if MODULE_SIG_SHA512
--
2.51.1
next prev parent reply other threads:[~2025-11-11 15:49 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-11 15:48 [PATCH 0/2] module: Remove SHA-1 support for module signing Petr Pavlu
2025-11-11 15:48 ` Petr Pavlu [this message]
2025-11-11 22:37 ` [PATCH 1/2] " Aaron Tomlin
2025-11-11 15:48 ` [PATCH 2/2] sign-file: Remove support for signing with PKCS#7 Petr Pavlu
2025-11-11 16:53 ` James Bottomley
2025-11-12 13:51 ` Petr Pavlu
2025-11-12 15:05 ` James Bottomley
2025-11-12 15:36 ` David Howells
2025-11-12 15:47 ` James Bottomley
2025-11-12 15:52 ` David Howells
2025-11-12 15:58 ` James Bottomley
2026-02-02 11:24 ` [PATCH] sign-file, pkcs7: Honour the hash parameter to sign-file David Howells
2026-02-02 11:27 ` David Howells
2026-02-02 12:25 ` Petr Pavlu
2026-02-02 17:01 ` Sami Tolvanen
2025-11-11 16:22 ` [PATCH 0/2] module: Remove SHA-1 support for module signing Sami Tolvanen
2025-12-22 20:24 ` Sami Tolvanen
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