From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792758507; b=y91lgm1jq+PknaFvFhEJIgWTJu9V9IUh09gz8t8uLDSSwOzrPc9JOrs7xCYmytu6vDZc 4dYrElSedkn3qxBu5uotDfwK3TmMiFsvpKriGXcplP4HZMFWwwsVMBAtIVihkI9TqeNxL rEIe/lpFnm5kMLXTA2B+so7osM6uZBznfMfXispsVPWThy/yj514S+jcUvYJnts+MUGHh KK1LW369En8Rh+smLMepVLxCDf3B2QdWiCKt3Z654+kRPWqjtALdsTLV30wledS/HC+D9 WUEu1J0BGFkZTg/on/+8z3ZoqMLlHJze/N0KMlmxqZdnt0XguF1pB98vacUQ5hFi6bg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792758507; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=h2yv/hj0WDpKJ/je5WQKd3uGQZ0jMDC+SeY0v8CSH6c=; b=kESiUx/8UGsYIKA7g0ig3e7TbB8NncQErNYtHimN1LL8JE54fYN46s6fVefbLSBwJORn 3Rrj8Qv7K02phfmiKpMEgquxf7fPa3cR617n9RVKluYzZ0/V0emEtxGz8cr3bP9RGLhLr Pp95CxphahEu4Lt2AnhaxsBZS06/BV7nl2J75kORC6wvPlxcIG1daEA128sQS4EbDjxtH GF+WWbCVeG2e/6n8fID8vt0p4hVywOaIXV5dAkuUZW3zMmdUPrPkT8AQEhBTHwGv3VUkq Spu5Iy7EbbgsN34Ky+E0g9zcCYDwyezSbW0PH5C7Ceb9hW/U8EJSs5WbTlV+z/3j+hg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=fkCzCd41; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with UTF8SMTPS id 416A1606A31E; Fri, 23 Oct 2026 12:28:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=fkCzCd41 Received: by smtp.kernel.org (Postfix) with UTF8SMTPSA id 8DD331F031E2; Fri, 23 Oct 2026 12:28:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792758507; bh=h2yv/hj0WDpKJ/je5WQKd3uGQZ0jMDC+SeY0v8CSH6c=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=fkCzCd41+NGM9bGhG6CQyssly6RFqC5ddd3raqOhrhFEt7UWDNEgeDa0BW+KpHy0M r5VeZTgsH1vAKUboNFggZ2fEQg3JM2epe7CDSdZDkE50MnA7lWB0QuvlBwjqz89d4H mdqM4sg8nsk8DxUusmcgvk+0anuHtgxGbFxJlV5ZYWzfqQIxs1sOxhvy1nAp69dgR3 fldC+tXLgG3yIjnsNn43pYIbFeMYm1C6CgiYoq//Hb22LrFLOb38Jtf56KhlvkxEHI lK5vQa70mmcA13RAYKIrzkmWvFYC72nmhARBYbx1bpx8JQ12Wn99ivwEqiYTXRWVFI HIB+683XbAhgA== From: Jarkko Sakkinen To: David Howells Cc: keyrings@vger.kernel.org, Linus Torvalds , Jarkko Sakkinen , stable@vger.kernel.org, Eric Biggers , Andrew Morton , Paul Moore , James Morris , "Serge E. Hallyn" , linux-kernel@vger.kernel.org (open list:LIBRARY CODE), linux-security-module@vger.kernel.org (open list:SECURITY SUBSYSTEM) Subject: [PATCH v2 3/6] KEYS: Verify the key identity in __key_unlink_begin Date: Fri, 23 Oct 2026 15:09:23 +0300 Message-ID: <20261023120953.1206778-4-jarkko@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20261023120953.1206778-1-jarkko@kernel.org> References: <20261023120953.1206778-1-jarkko@kernel.org> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit When two keys have identical type and description, linking the second key replaces the first in a keyring. However, attempting to unlink the first key (no longer in the keyring) unlinks the second key. This happens because __key_unlink_begin() calls assoc_array_delete() with &key->index_key, matching only on type and description rather than the key's identity. Example: keyctl new_session >/dev/null keyctl newring ring_a @s keyctl newring ring_b @s A=$(keyctl add user A ss %:ring_a) B=$(keyctl add user A qq %:ring_b) keyctl newring R @s keyctl link $A %:R keyctl link $B %:R keyctl unlink $A %:R keyctl show Verify the key identity before unlinking, and return -ENOENT on mismatch, instead of unlinking the key with the wrong identity. Cc: stable@vger.kernel.org Assisted-by: LLM Fixes: b2a4df200d57 ("KEYS: Expand the capacity of a keyring") Reviewed-by: David Howells Reviewed-by: Eric Biggers Link: https://lore.kernel.org/r/20261020174325.2229448-4-jarkko@kernel.org Signed-off-by: Jarkko Sakkinen --- security/keys/keyring.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/security/keys/keyring.c b/security/keys/keyring.c index 2c54f7f84c55..5281da9d5bf7 100644 --- a/security/keys/keyring.c +++ b/security/keys/keyring.c @@ -1506,9 +1506,15 @@ static int __key_unlink_begin(struct key *keyring, struct key *key, struct assoc_array_edit **_edit) { struct assoc_array_edit *edit; + const void *object; BUG_ON(*_edit != NULL); + object = assoc_array_find(&keyring->keys, &keyring_assoc_array_ops, + &key->index_key); + if (!object || keyring_ptr_to_key(object) != key) + return -ENOENT; + edit = assoc_array_delete(&keyring->keys, &keyring_assoc_array_ops, &key->index_key); if (IS_ERR(edit)) -- 2.47.3