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 481914C6EEF for ; Thu, 3 Sep 2026 15:00:47 +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=1788447648; cv=none; b=jD/W3pOAQpdQCPpS4IYC4P4BFdXH89qOJPfzGV3q5Ob+WilTolip1MJ5nJwXf4lQstVn1FuCxl7Qprbx8v4wh8yu0dhVh0GbDnEAHJjgWVDCVNBwFcDBmZYWqeVy+LQ8QuZRxqZ663PxfA895T5KP+BYM6XQl2FW3Y4/CEacjpc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788447648; c=relaxed/simple; bh=xcJkbqHq6/Qpm8/rkb9HFtj0Nqd+LKyMydPeSjmE9dE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kWpDYnj96Esh9YbmtzD8c3lUBvoMBDDY8TV923A2XP0FjL7gMqtUnjJNDP9MpAE6xhuwKeScSgTRO2Q+c8p5LYYw6JFpSJMg38K2VnxcbhXnKnoYNU1GifewLyQFbjuGF0ykI2WI6AjXIRYxyXaDDKexlPYJE+Gx4PfHQ7zhrNc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QLgCStq5; 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="QLgCStq5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8E35D1F00A3A; Thu, 3 Sep 2026 15:00:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788447647; bh=PMT57Dsq/Xzh80M9xx5BqvchArYSaC3g0GJvK8zSy3g=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=QLgCStq59GLvJ30BdqfKGeLbT/6iMFPGq/b1ivrYoww1wqjKI6URDscvSpo6qkyyj fGSp5VljsB526W+e5s8+LL/phWL4VP3K/Ql3yBt6NygqAPdqNBkgYrBT/bmYUkoaC4 fkqKWWaqPgL+Pzfs72ExrOxJsEKXwZZi+WF/+U/94xwNuCqcGQrJcVpmTzisXdbor5 qhRmXkg5WWwm+MYF7za14LGXSd7KKkLn0hJM7mZi82PmX3PuRwMCwm+Bo43my9Exh9 GN689jF7ZbnjrEVyRXY6oyCV/TmDEuRCTRDkfOpwT4CSFFARD71dF4xtbZWOOoyk+4 uVUBH0/0OPyHw== From: Sasha Levin To: stable@vger.kernel.org Cc: Chengfeng Ye , Jarkko Sakkinen , Sasha Levin Subject: [PATCH 6.12.y] KEYS: trusted: Fix TPM teardown ordering Date: Thu, 3 Sep 2026 11:00:44 -0400 Message-ID: <20260903150044.855866-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026090320-scalded-unclaimed-9b48@gregkh> References: <2026090320-scalded-unclaimed-9b48@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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 e73f2c6c817a0..b5781c5071395 100644 --- a/security/keys/trusted-keys/trusted_tpm1.c +++ b/security/keys/trusted-keys/trusted_tpm1.c @@ -1069,10 +1069,10 @@ 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