From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 862A2331EB8 for ; Thu, 16 Jul 2026 19:49:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784231382; cv=none; b=jWMwDLzvrTpucvv9iZUXcgRY8cfieR6koRZksyjuwcoLDqMXZ72k4u0n+9zVsmsK8TEjylynnM+6kcezceKQ3IwOK18UHrfyrR7BL+fVkrTSFRRIIRaQ01GF0BEkycWnFl/SJsP/MBI0VtpLtbpqZhMwvYPH3NQIjtiX56fbknA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784231382; c=relaxed/simple; bh=XSEsEgNlwWPvDsdw1SmXQc6lSpmBAnebdVFgAvN6ddM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=mPldzzuaWR3IN6C9nk5TAy8DY4uNHsbXiDvHDREBbcf+O5WFf7Jojzoj5M1JXO05kBDlwgfupTll4tBog37/oEnpjNdpSXLCBOWcGKQWK8SDgnP9Ihhcs+ukymAsd++09PXghZmw7xoJqrOnrphA1GCSHTBMm5yKJxg0M1H2I1Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=S3jYvRnt; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="S3jYvRnt" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6E1B21F000E9; Thu, 16 Jul 2026 19:49:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784231381; bh=/Pbz57vgSSvpW4MaE+HoWOZ7XihtFdszrTHbyvVHM8I=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=S3jYvRnt8cRcAnaJQlX2x1m2GWFLw3YsDLsA8btYwDc4VjkJnIw7H2kxIBf05js/q 512hDV7xsG7o1FqMbXP//vVMvjV7TW7A9Yi1K4Ckp+pOO9JYm8YYn4/t9IrAXOYmrm P4+eYcjJBdYJiV3LDUjdsmR4WHeL06MNAHog/xZaXNtLI4IHU5adBQlaoxlIjALM+e uJziM155MNZIal4lcLdBRwj7txER9CYrfW5BVcjtYa5eoZhX4WGZFTX33MFvznw3ff uF+ef3fbRIV1XsoKUg7bge7GxcGzD5ckfpZ+O2L8fxBgRLH8vKic9oRrr9vD8s+4NN 84LzVAknpu+cQ== From: Sasha Levin To: stable@vger.kernel.org Cc: Lukas Wunner , Sashiko , Ignat Korchagin , Alistair Francis , Herbert Xu , Sasha Levin Subject: [PATCH 5.15.y] X.509: Fix validation of ASN.1 certificate header Date: Thu, 16 Jul 2026 15:49:38 -0400 Message-ID: <20260716194938.1111666-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026071443-crouton-afterlife-63a4@gregkh> References: <2026071443-crouton-afterlife-63a4@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Lukas Wunner [ Upstream commit 3b626ba431c4501512ad07549310685e07fe4706 ] x509_load_certificate_list() seeks to enforce that a certificate starts with 0x30 0x82 (ASN.1 SEQUENCE tag followed by a length of more than 256 and less than 65535 bytes). But it only enforces that *either* of those two byte values are present, instead of checking for the *conjunction* of the two values. Fix it. Fixes: 631cc66eb9ea ("MODSIGN: Provide module signing public keys to the kernel") Reported-by: Sashiko Closes: https://lore.kernel.org/r/20260508033917.B5873C2BCB0@smtp.kernel.org/ Signed-off-by: Lukas Wunner Cc: stable@vger.kernel.org # v3.7+ Reviewed-by: Ignat Korchagin Reviewed-by: Alistair Francis Signed-off-by: Herbert Xu Signed-off-by: Sasha Levin --- certs/common.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/certs/common.c b/certs/common.c index 16a220887a53e8..c7bcf3f6a77e39 100644 --- a/certs/common.c +++ b/certs/common.c @@ -20,7 +20,7 @@ int load_certificate_list(const u8 cert_list[], */ if (end - p < 4) goto dodgy_cert; - if (p[0] != 0x30 && + if (p[0] != 0x30 || p[1] != 0x82) goto dodgy_cert; plen = (p[2] << 8) | p[3]; -- 2.53.0