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=1793210495; b=paWjA3ifx98R4XnBoFyERm9i9RiwBKjkTEAc4w2eqILo8U2xLhyIb6WpMStS4lP+yPsv 9DS1oBy2Xlqg4EiDN3pt1KmRJXR4ifmwz42mWymttsedacMxan2veC0gTKAYUAhYdqs9K mfMg+Oc4AbssieQo3l4Rl/Rp8Ef5o3NkMZcaqWISVSMdD+jMXzWCyQtXA9PUWmOaS43Lv 2h+uU4EMQXmqyMjA3lLT34xVOgWvECCNS9IGvHfIE3KQWUgQMQE+eBYYGWveyLavfzPQs +d3pw1PKThy8zYtnE+yWEgfAzN5bs5RxjRDg8aTBItEh0wXwxq52CkdaZhOVMvjSPtg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793210495; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=leSGv2K5N0Vx6jHuROUI5Ommz7TRu49Rlu/66RSffY8=; b=igELOH2iLEHUS4Qj1kN5HnsVlaAysBA4p7NFgdMGYRDqjilAxuUaIs4D6L5AnjkLiJ7z qV11gJ2DOwVsHLI1mm9ccMCaSxqde11YKlEOKE17E7XujZAp4g7Nhnj+GTP2K/4tdSsno HGD8kQVUBkcLLPDVOD0qOzhbxzKXkPevvgt0zd1R4GOAbpr5JKFfhx5+vLoCUsTjicofu P0mPCoD2jUPJrGd6aV3LdoJRa6KZkiph5r8r3UvmGr366ubHJSMbi3tUBmTW0KEvbrBuw /3mls3h8tq8tC8HKur7FEH+m/2eRrdRJ9JDbKKa1xiAKzFTshpk+2K/sI6fbM5k8BSA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=n71BLwQK; 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 ESMTPS id 4841D606A321; Wed, 28 Oct 2026 18:01:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=n71BLwQK Received: by smtp.kernel.org (Postfix) with ESMTPSA id 97CF21F01825; Wed, 28 Oct 2026 18:01:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793210495; bh=leSGv2K5N0Vx6jHuROUI5Ommz7TRu49Rlu/66RSffY8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=n71BLwQKsZvm26gq506HMYpoC7sjGy3AiYdA8HlIReeCSyWqyDA64UVnFimiyCgRw 0tmBg/SU40OI3ssvCfRTl/6i4b1Smn4g/pLOTf7QOlG2UZi9OO/bwEQUqTIEpl/MNt bxyM3LgH9beGGGVf+FhgW5z9Q6vS/SLBvelL6+rs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Chengfeng Ye , Jarkko Sakkinen , Sasha Levin Subject: [PATCH 5.15 047/571] KEYS: trusted: Fix TPM teardown ordering Date: Wed, 28 Oct 2026 17:53:14 +0100 Message-ID: <20261028170009.144350201@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028170008.009143722@linuxfoundation.org> References: <20261028170008.009143722@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chengfeng Ye [ Upstream commit 5e2d672280d97d83de43031d93761b12dadd7b8a ] trusted_tpm_exit() drops the TPM chip reference and frees the digest array before unregistering the trusted key type. key_type_lookup() holds key_types_sem for reading until the key operation finishes, while unregister_key_type() takes it for writing. It therefore provides the synchronization point that must precede backend teardown. The current order permits this interleaving: CPU 0 CPU 1 trusted_tpm_exit() key_type_lookup("trusted") put_device(&chip->dev) trusted_tpm_seal() kfree(digests) pcrlock() unregister_key_type() tpm_pcr_extend(..., digests) CPU 1 can consequently dereference the freed digest array. The chip can also be released before callbacks stop using it. KASAN reported: BUG: KASAN: slab-use-after-free in tpm_pcr_extend+0x1f0/0x200 Read of size 2 at addr ffff88810872d000 by task poc/89 Call Trace: tpm_pcr_extend+0x1f0/0x200 pcrlock+0x42/0x70 [trusted] trusted_tpm_seal+0x1b6/0x570 [trusted] trusted_instantiate+0x293/0x340 [trusted] __key_instantiate_and_link+0xb2/0x2b0 __key_create_or_update+0x61e/0xb50 __do_sys_add_key+0x1b8/0x310 Allocated by task 88: __kmalloc_noprof+0x1a7/0x490 do_one_initcall+0xa1/0x390 do_init_module+0x2df/0x840 Freed by task 90: kfree+0x131/0x3c0 trusted_tpm_exit+0x59/0xa0 [trusted] __do_sys_delete_module+0x346/0x510 Move unregister_key_type() before releasing either resource. This stops new lookups and waits for in-flight key operations to finish before the backend state is destroyed. Fixes: 0b6cf6b97b7e ("tpm: pass an array of tpm_extend_digest structures to tpm_pcr_extend()") Cc: stable@vger.kernel.org Signed-off-by: Chengfeng Ye Link: https://lore.kernel.org/r/20260731140925.2973492-1-nicoyip.dev@gmail.com Reviewed-by: Jarkko Sakkinen Tested-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen [ preserved the additional trusted_shash_release() cleanup after unregister_key_type() ] Signed-off-by: Sasha Levin --- security/keys/trusted-keys/trusted_tpm1.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/security/keys/trusted-keys/trusted_tpm1.c b/security/keys/trusted-keys/trusted_tpm1.c index 4863ee08b7b11..c482c54be918c 100644 --- a/security/keys/trusted-keys/trusted_tpm1.c +++ b/security/keys/trusted-keys/trusted_tpm1.c @@ -1058,10 +1058,10 @@ static int __init trusted_tpm_init(void) static void trusted_tpm_exit(void) { if (chip) { + unregister_key_type(&key_type_trusted); put_device(&chip->dev); kfree(digests); trusted_shash_release(); - unregister_key_type(&key_type_trusted); } } -- 2.53.0