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=1792887126; b=2Ie+TcNKlOFPBjHCfWwk5BJK5QHGfvhzUKB25fzuGqilIzUKCu0Ug4KboE01/LOEDKSG SuEwmHh9n/GXqq6zIA8s3RlKZQB35ZEQlphQo8YDKAP0/yVD43rGk+TBWICG9Jg97XTam Th0jWNNzAy94I6ABb0N1666AJGVaUvSVroJFpQZXT9trKnAz6Prn5xN+H7Myq2sxEVGPF vApzF6LRWV3wuhUD9REhxUNFM6yNyt9tHJ9SmJwCmqvSjX4ajQ53ZgcJsAm5GIU2M+KSs VcAKHk9YRzZ7mdTNglfr6FW2ScJBpEU7dQh4M/b1WCFffilQqk4fTTOjIavUhatSMqg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792887126; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=ZyI2ZxRsCFGR8Z+gBT3qLKeB8C/aqFH9i5cqte353Mc=; b=WUTm/oeq2JKAFrZTk19I+yCeomclL1iOe4EnT52P/pyrGH1bo9ocKelyJiVw2nFouZPj 18wFPoqf0H+MH6gbjkkY80vRddQ66g9ru2LPQEsQATMP0Mp5y6bpq3uOe+OI1jltFFF6n u5ykgcAZDeABMAa8vq6s5dC+lHk+TDWpDRXvGpNWjJ6cSZ4EBWu/b/dHWJKdEP1PCbO5C uSTpKNOEcmBLOX/MYFkElOqLkvBe3Krpgh4cTCAb5ZlM/ErWbTdyc96e/0HST5/0IYtH2 8Wgr9BMWx+tK5KqWj5ycQCAFbKLAj5OZl8To5/HMi1cBew9EJ2Lb/AxgBQcn8sJdVXQ== 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=SRXl4IHM; 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 51D4E606A31A; Sun, 25 Oct 2026 00:12:06 +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=SRXl4IHM Received: by smtp.kernel.org (Postfix) with UTF8SMTPSA id 957461F01828; Sun, 25 Oct 2026 00:12:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792887126; bh=ZyI2ZxRsCFGR8Z+gBT3qLKeB8C/aqFH9i5cqte353Mc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=SRXl4IHMSUVx7kNXB8XeF3GLv4W/hn2SSp2MSA5poZ4A4/edwOyBu7RQ128K/p+5A WaTiYbufxYBjEGEbMlFfVzJje8OWSO3k6wWAv4bO+AdcR5vwxmG4O/zvjLtSpoF/QN 5ZTFcl6XCcgS4L2A0EnRDtu7it44XkaE2pPWAHUncdOmYw0sjE+vv7FK/hWb9B8VaZ iqeklSSexwn0uIqHacAk6uMDDN15BFnycJijCPp42imOwofqNHDBKcLlbPLVcAhoWp X5ft1xMUOHl2tWfeMxhgbaoMxIxTayBZo12/AieJ02S3Sn52dnWy4hgy2uy7sSKRZA EV2qULo/D5ZPg== From: Jarkko Sakkinen To: David Howells Cc: keyrings@vger.kernel.org, Linus Torvalds , Eric Biggers , Jarkko Sakkinen , stable@vger.kernel.org, Andrew Morton , Thomas Graf , Herbert Xu , Paul Moore , James Morris , "Serge E. Hallyn" , linux-kernel@vger.kernel.org (open list:LIBRARY CODE), linux-crypto@vger.kernel.org (open list:RHASHTABLE), linux-security-module@vger.kernel.org (open list:SECURITY SUBSYSTEM) Subject: [PATCH v3 3/6] KEYS: Verify the key identity in __key_unlink_begin Date: Sun, 25 Oct 2026 03:10:11 +0300 Message-ID: <20261025001105.1824178-4-jarkko@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20261025001105.1824178-1-jarkko@kernel.org> References: <20261025001105.1824178-1-jarkko@kernel.org> X-Mailing-List: linux-security-module@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 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