From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qk1-f176.google.com (mail-qk1-f176.google.com [209.85.222.176]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2DC2526A1C4 for ; Sun, 19 Jul 2026 16:15:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.222.176 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784477720; cv=none; b=T3pDxmUCb8TYzyJS1zop/nzVZuB3f9l069Y7x4YGHx7RzNLaJvL//Tu2FdIfdHlCoOaAnx1SnruvQ3nLZfjwcFhCiCwgqciHF7xgLmhdu93AaO9IW2EvOUaRLcYoupTlHHtl9H92B8FCtT5A8x9wEaVbEzqFZxdMoEgM05lD0J4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784477720; c=relaxed/simple; bh=z7iFnYhuNkpMKfpkGAHIAltacElFBDKQMCZumHmuODE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=G9TJpxslpWdrWf4EB9/5Sz1IitIpdSllvLPdmXANBqHBVTrgRdBE0C7HXRM4pUfrVQaLF97CTBaLzqxGmrK58e7+5RCsZIv1ZrynQh0yYBkpZJXpfz1uyVmuvCTeCq57o4qNPfqX0oCdyuaYbqCMlpj3v66g4HxuODp0quKpfnM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=KK10IMqq; arc=none smtp.client-ip=209.85.222.176 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="KK10IMqq" Received: by mail-qk1-f176.google.com with SMTP id af79cd13be357-92ea24a2dbfso791744385a.0 for ; Sun, 19 Jul 2026 09:15:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1784477718; x=1785082518; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=sv09Y2zV5fntrZQk40NqD/qbsVElT2FYKTtooq7g6h8=; b=KK10IMqq0Ej7p10MaQR4YYnt3Iv8anpcpvUcl5gj692/UEiKDpQS1VFq9657BayI47 +hXQZDKACY9YreHeZVU/JKZndADrs17BOxd9SZCyGKIkFhdRsmUZaEgX65aK4Myf7mn6 rqax2ajIFwrAttED0TN616MOl3N71WYt8lyU3JKmNHjYX5CDObZiiBHZfC11Qc25Djlu Ar4+oP5duGpP1XTqpLmgWMTHILbCWzpmUvVqsNjGs7Z/sLIQDgnDvotMkBFQjsvGwaWI ujeG+btvkJI09WANODVjSg/n7+LaDeq02T4spElnhnMRHlh4UDTHICn8FW1R6I3U++DQ SRrQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1784477718; x=1785082518; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=sv09Y2zV5fntrZQk40NqD/qbsVElT2FYKTtooq7g6h8=; b=AwtkgtpG2gwgebW3bD3liYcKZKfYgXdI2TlZ7dqvMfoQDrqjR/0b9P6r63oycWsyEu rr2ffNwd7wR2E0lW07qAiw1242KJK50AvNjfv3re3o4y2wCrCSGTtjwv9u88uQRhYWl5 ASBhN7YeLJGGRO/v5Zbx4b6LJcngLEb53epcPAwiPsKMEu4pbsP08PE4UvP7S54sQZZY t2YxT2vfMfhVzoub5cnIGYQq3LXk6LcQ+gc5rA8kSk44jDaTEpEsC7uOVcpZjilZNyvN 2ST1I5fabAuclxNFch7BUpbZl1LKWtbVWOek0CKDfu5uqZKPGbgd5YHdRPiWfAyrgvge HS4w== X-Forwarded-Encrypted: i=1; AHgh+Rp3awOMBjjKG7RqLFMPk109Z2sj74H4zRRZ9lLJzkeW61yu6WpausKLdk+oEiEhpwAcVyCeSoV5oCv6jHw=@vger.kernel.org X-Gm-Message-State: AOJu0YxtwZwzjoDJwVpOo50tQjoMdndu7LYgrHoa7cti8HBIjaweXlqq kHAPW5DipHEuJu9Kbr//7VjkA4cWy12xesl3fbGgtBseRQvuz58TeAGz X-Gm-Gg: AfdE7ckvYNnyShUkr0zmD2eyegAjGNbdDQw8GXOycjnxKJGMj2UjJNv66M1FMcEfyrI nq/FnNJ1ozLz/hTE7nAmou20IK4v63UoJwXr3oYBrjmc1IivehxbLxzOX0t3sIACPZwMVEPQTqJ ai71I/CUqjLRBmyWGZWxWhxtyIjZ3WsiAmLaOr4xKOy2AZCJXEp/H1JQpnX1GgkXKbylEraaJMH 1aTWs/HU+Cj22GdBkC04zouCvlM0WBd+yRoITf3y+yeIjg0tdCqXv2lO+Va+y3aqtTS6q8QYfZj 21mNbsCsfdTIdu6nRzVDbBk1dyOAgmExJAsiwcDxqY0Gmj7TCwdXEV5Aud6grrPvBfWWhPzo+Gg wtsQ10087QPWMfULYS2b6wZx9DU2V1KzqKVh/IwnJmLOJkaJXxP0swxRdgLmRxmZThTxjLGXHfl ntHekE4UT0Nb5lJ4TWV5O+7ZZJkYEw3+IjZew1MaYviEY2YcUamcmZGg5ZX6yfKIcsoxorTvmua A9t92qrRu4iYMZ+Oz5Q9zm52Pf5iMfs X-Received: by 2002:a05:620a:29c4:b0:92e:bc32:8ca7 with SMTP id af79cd13be357-930b3ef7168mr1108379385a.33.1784477717968; Sun, 19 Jul 2026 09:15:17 -0700 (PDT) Received: from server0.tail6e7dd.ts.net (c-68-48-65-54.hsd1.mi.comcast.net. [68.48.65.54]) by smtp.gmail.com with ESMTPSA id af79cd13be357-930b52fe271sm672374185a.16.2026.07.19.09.15.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 19 Jul 2026 09:15:17 -0700 (PDT) From: Michael Bommarito To: David Howells , Jarkko Sakkinen Cc: Andrew Morton , Paul Moore , James Morris , "Serge E . Hallyn" , keyrings@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 1/3] keys: fix out-of-bounds read in keyring_get_key_chunk() Date: Sun, 19 Jul 2026 12:15:03 -0400 Message-ID: <20260719161505.2423935-2-michael.bommarito@gmail.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260719161505.2423935-1-michael.bommarito@gmail.com> References: <20260719161505.2423935-1-michael.bommarito@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 7bit For description-level chunks keyring_get_key_chunk() advances the read pointer by level * sizeof(long) past the inline prefix but only bounds-checks the prefix, so a long enough key description is read past its kmemdup(desc, desc_len + 1) allocation. Compute the full byte offset and bounds-check the description against it before reading. The walk only reaches a description-level chunk when two keys collide through the hash, x, type and domain_tag chunks, so this is reached from an unprivileged add_key(2) with a crafted pair of same-type keys whose index hashes collide; KASAN reports a slab-out-of-bounds read. Fixes: f771fde82051 ("keys: Simplify key description management") Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Michael Bommarito --- security/keys/keyring.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/security/keys/keyring.c b/security/keys/keyring.c index 7a2ee0ded7c93..085f7a743354c 100644 --- a/security/keys/keyring.c +++ b/security/keys/keyring.c @@ -271,6 +271,7 @@ static unsigned long keyring_get_key_chunk(const void *data, int level) unsigned long chunk = 0; const u8 *d; int desc_len = index_key->desc_len, n = sizeof(chunk); + unsigned int offset; level /= ASSOC_ARRAY_KEY_CHUNK_SIZE; switch (level) { @@ -284,12 +285,12 @@ static unsigned long keyring_get_key_chunk(const void *data, int level) return (unsigned long)index_key->domain_tag; default: level -= 4; - if (desc_len <= sizeof(index_key->desc)) + offset = sizeof(index_key->desc) + level * sizeof(long); + if (desc_len <= offset) return 0; - d = index_key->description + sizeof(index_key->desc); - d += level * sizeof(long); - desc_len -= sizeof(index_key->desc); + d = index_key->description + offset; + desc_len -= offset; if (desc_len > n) desc_len = n; do { -- 2.53.0