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 A2221369997; Fri, 16 Oct 2026 21:54:08 +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=1792187649; cv=none; b=SJMLE4BQjyw2sVSlgy6OkmFssrBS5CC4JUoWNtBSDpTbM4DGcGCfCPX++T6V1MurCKoO+x5yhIJ0d666mzb2B/nvJbLJZBSxS+1ou2wNi1ZVZvKuMShteM6/ADeU91Om6cLW69YdcIOaK6+CVP5+AzwIkB5Kuy4YJweLzF6roLY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792187649; c=relaxed/simple; bh=ZWM0sMHH8wKCZK3iuYqtS4+tjmbExVll3Zlm0HAqbFc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=CoY+thC9PH15mHSP1ckMLknJZHj4/jigXBDL3/qpk3etc5tmiTDaAnbvD9LtTyOrAc7WN+kLtso1A4IT9T/OrrFhodUn6o82hGLrXXOOSvPASSHKJCTuzWdWGnLC+TRwsY5oBnUVBHe68wFaQkEDATgIGqnVhhv95L8guap7O9k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Q7x35s3S; 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="Q7x35s3S" Received: by smtp.kernel.org (Postfix) with UTF8SMTPSA id DFA4F1F000C5; Fri, 16 Oct 2026 21:54:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792187648; bh=YrzgZm1IM3e48u8hZMm1oRsSxJM6fwWMAcAQ5sfnEQA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Q7x35s3S8/J0gSwHp+bXSXmf5l0QYXJnj4e5Q7hwDj2GQzVSnjGSYK+69w9r+SsEl M7IMqCv3vLB9dfVEqIrWWAVxgBGrLZHP0FgA/xlost8UYny+SQlobRKx/6EW4CZHL7 XjEP+i//gjC7gTZe6F8Xd5noK6QhpQnddTYPCD3Fqp8TPaseJ//DCV/1kIEuWHSe8J fTgyw6oEm0P4Avy1box+vAoravVaIpUJRFmtXa7radifnDKT1pfmv93+SZwfh9bE/2 xu2wjctkK3hIyHhEYbxTETOgtiowK1JnHgtQyDuc9/rj2+OK4Y3dbGLqMWEX54kXhQ /fztsYip/TK3w== From: Jarkko Sakkinen To: David Howells Cc: keyrings@vger.kernel.org, Linus Torvalds , Jarkko Sakkinen , Alasdair Kergon , Mike Snitzer , Mikulas Patocka , Benjamin Marzinski , Eric Biggers , "Theodore Y. Ts'o" , Paul Moore , James Morris , "Serge E. Hallyn" , Shuah Khan , Christian Brauner , dm-devel@lists.linux.dev (open list:DEVICE-MAPPER (LVM)), linux-kernel@vger.kernel.org (open list), fsverity@lists.linux.dev (open list:FSVERITY: READ-ONLY FILE-BASED AUTHENTICITY PRO...), linux-security-module@vger.kernel.org (open list:SECURITY SUBSYSTEM), linux-kselftest@vger.kernel.org (open list:KERNEL SELFTEST FRAMEWORK) Subject: [RFC PATCH 4/6] keys: Add keyring_is_empty() for {fs,dm}-verity Date: Sat, 17 Oct 2026 00:53:02 +0300 Message-ID: <20261016215326.4110064-5-jarkko@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20261016215326.4110064-1-jarkko@kernel.org> References: <20261016215326.4110064-1-jarkko@kernel.org> Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit fs-verity and dm-verity read assoc_array's nr_leaves_on_tree directly to check whether a keyring is empty. Add keyring_is_empty() and use it in the both callers. Signed-off-by: Jarkko Sakkinen --- drivers/md/dm-verity-verify-sig.c | 2 +- fs/verity/signature.c | 2 +- include/linux/key.h | 1 + security/keys/keyring.c | 10 ++++++++++ .../selftests/dm-verity/test-dm-verity-keyring.sh | 2 +- 5 files changed, 14 insertions(+), 3 deletions(-) diff --git a/drivers/md/dm-verity-verify-sig.c b/drivers/md/dm-verity-verify-sig.c index b2b55c41e2cb..2ccb71bfb3ca 100644 --- a/drivers/md/dm-verity-verify-sig.c +++ b/drivers/md/dm-verity-verify-sig.c @@ -153,7 +153,7 @@ int verity_verify_root_hash(const void *root_hash, size_t root_hash_len, if (ret != -ENOKEY && ret != -EKEYREJECTED) return ret; - if (dm_verity_keyring->keys.nr_leaves_on_tree && + if (!keyring_is_empty(dm_verity_keyring) && dm_verity_keyring->restrict_link) ret = verify_pkcs7_signature(root_hash, root_hash_len, sig_data, sig_len, diff --git a/fs/verity/signature.c b/fs/verity/signature.c index 0302a4e506ec..890d33b9d812 100644 --- a/fs/verity/signature.c +++ b/fs/verity/signature.c @@ -67,7 +67,7 @@ int fsverity_verify_signature(const struct fsverity_info *vi, return 0; } - if (fsverity_keyring->keys.nr_leaves_on_tree == 0) { + if (keyring_is_empty(fsverity_keyring)) { /* * The ".fs-verity" keyring is empty, due to builtin signatures * being supported by the kernel but not actually being used. diff --git a/include/linux/key.h b/include/linux/key.h index 26139c3adf62..d82253b06c54 100644 --- a/include/linux/key.h +++ b/include/linux/key.h @@ -436,6 +436,7 @@ extern int restrict_link_reject(struct key *keyring, struct key *restriction_key); extern int keyring_clear(struct key *keyring); +bool keyring_is_empty(const struct key *keyring); extern key_ref_t keyring_search(key_ref_t keyring, struct key_type *type, diff --git a/security/keys/keyring.c b/security/keys/keyring.c index 9ccce0db0665..613d1db41611 100644 --- a/security/keys/keyring.c +++ b/security/keys/keyring.c @@ -443,6 +443,16 @@ static void keyring_destroy(struct key *keyring) assoc_array_destroy(&keyring->keys, &keyring_assoc_array_ops); } +/** + * keyring_is_empty - Check whether a keyring contains any links + * @keyring: The keyring to check. + */ +bool keyring_is_empty(const struct key *keyring) +{ + return READ_ONCE(keyring->keys.nr_leaves_on_tree) == 0; +} +EXPORT_SYMBOL(keyring_is_empty); + /* * Describe a keyring for /proc. */ diff --git a/tools/testing/selftests/dm-verity/test-dm-verity-keyring.sh b/tools/testing/selftests/dm-verity/test-dm-verity-keyring.sh index 1f9601ef22f8..792449d356cf 100755 --- a/tools/testing/selftests/dm-verity/test-dm-verity-keyring.sh +++ b/tools/testing/selftests/dm-verity/test-dm-verity-keyring.sh @@ -746,7 +746,7 @@ test_keyring_inactive_when_empty() { log_info "TEST: Verify dm-verity keyring is inactive when sealed empty" # When keyring_unsealed=0, the keyring is sealed immediately while empty - # This means it should NOT be used for verification (nr_leaves_on_tree=0) + # An empty keyring should NOT be used for verification. log_info "Keyring state (should be empty and sealed):" list_keyring_keys -- 2.47.3