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=1792460364; b=cEQgPJfFTGU8hECfIWTVY+/ZQpb0eUGnGLnX0xejhacmsvpPqup3zKqKdNGYGgwcLBAY AS7INcJvBRRIR2D91o4z85L3ENEXlCFGYskIBvEE/f4DIsed0e+BPFfAR8lNss2gvHJLd pQIEatlztkxHka3wbo7Avc/V+QDyBLrOGUMGY6zk3UMM1JducCL0E9Y5+1a1aEEX3PHzC XWJVqIq9TeET/n/OIG+Ollss2opqXNp+yar+Z7W8laKzVVvI2MJimjA1IoR5fQC5sxrCR rKOU3VHkqlb+F3/yKJJRNnTlGatWwAFNMOaOb3NNVMw1uaR0MjTmfXukLjV3VTjqprw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792460364; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=c8HLZiQwinILcb8NHotneX73qYTCfJXD1L2tSseW6Ug=; b=NCmCuNbtruOKHn76bQJhIHCI/dDJCZUwy0di1Mo3Aw5NL06n1odaAikArA6j39TCN69Q NhY/HwjBvV9ZR0kwtAM/dSpM3QapIcliB0N7PfWF5Vlqmz8Wj44l0p9wk4rZBTbVmprMC t18vH0GZ+ek88BEVFzxm50/Alnc/ZPe+NxhaokSqH7DnbLdWM1CtOLyYbmUWQ9+2BDM3H 1CJMZWTFmGt6lNY/MchMCtKom/MY/5MZWiTJSd+oFTm/Qk4xCVFj40DMRLyMU3+8X/R+P KcololfU6dLmQyVg6AF8E0fmsIxA4phVowZ+bHaWU4sF15e2YGl+63VRCiYgxZrXvCw== 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=QWxlEMXw; 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 9E1DC606A33D; Tue, 20 Oct 2026 01:39:24 +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=QWxlEMXw Received: by smtp.kernel.org (Postfix) with UTF8SMTPSA id EFAFA1F000CB; Tue, 20 Oct 2026 01:39:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792460364; bh=c8HLZiQwinILcb8NHotneX73qYTCfJXD1L2tSseW6Ug=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=QWxlEMXwNH8raa3urVkoyKULJtf9a615bycG98eky7T7XHpylDFueKgPeXYgB7Hoh whbeUP2TAUJKXxu8FBU689UkSalPDO8uoCrvLZFstTELeOXZP7juif7OXlmDrmbvWS tIr2oeCNGFuQ5xCKBx+nXafoFHkMiLTluILWHvYLKuGtdDPVgRtvohhYxPuqSh57lj SrDLEcUH6b1UHtnkorNk2Xdv3mqNKAyYzkIAXph3JaP3Wz1qM43TjKlM/cOMAG9v+T n+ILlXcq8AtIOeCIh+FA+WMmt1GVeEsbw0RMJ0q27ESOWNNZgYJefO9QwUtzD3/F/Q d/G0l0kk1w3FQ== From: Jarkko Sakkinen To: David Howells Cc: keyrings@vger.kernel.org, Eric Biggers , Jarkko Sakkinen , stable@vger.kernel.org, Paul Moore , James Morris , "Serge E. Hallyn" , linux-security-module@vger.kernel.org (open list:SECURITY SUBSYSTEM), linux-kernel@vger.kernel.org (open list) Subject: [PATCH v3 3/3] KEYS: Verify the key identity in __key_unlink_begin Date: Tue, 20 Oct 2026 04:38:57 +0300 Message-ID: <20261020013903.1244157-4-jarkko@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20261020013903.1244157-1-jarkko@kernel.org> References: <20261020013903.1244157-1-jarkko@kernel.org> X-Mailing-List: keyrings@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 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 7143f3079d20..b025331488c5 100644 --- a/security/keys/keyring.c +++ b/security/keys/keyring.c @@ -1501,9 +1501,15 @@ 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