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 71C2F4CDDEA for ; Sun, 18 Oct 2026 16:24:08 +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=1792340649; cv=none; b=sc7Sa/nu+rWH9ph9nAKXCHVa2DFS28ivqPzWzcKeON0d76KmKlEzBK0oS6fTsLW+da7rE5Cd/J+h7Ne8KkKv3yHY2J5RXYUYYCRZaJEKc7bunN+mho7o8nG8NU3Ilk+XvXPXCu6nbnp8Y78rjZFF65DwVAsIXyQeTjIy/5Ozwu0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1792340649; c=relaxed/simple; bh=/j7uJrl7PxeWQtmm2wWkICeSAaBeMmJjsigMB4k+HMY=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=Ez5oWd3LQUV5FWywv5377CDwfz1XoiCKPnK+zricBLBgVp+dZ1rtWLj59EWwtNEizKlLhYqDTATJGsYiWrGEgWqdcz6331aNPICnZcv/BnLRtP0pHPwARjzy+D1J7Dm3iZefBypfwF5ZCfSnYEqGApYM7pJJENHVubk5MyYoxW4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=sNcG3gyw; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="sNcG3gyw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 952161F000C4; Sun, 18 Oct 2026 16:24:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1792340648; bh=Iv8T7+pxUK1bdzhGdlGu4h+S/2KdMPzQ6bQGW7hT+fU=; h=From:To:Cc:Subject:Date:Reply-To; b=sNcG3gywjQ5jPAHGSFFWTakIckiQm9K6aqvFu5/xplUvJ6oz3TlVGDFwXxpzUkVEi 1bi4ipYBtyn+NqzaRxR0d6epFX/OK5Lxp6LGTHnYWIBqg01H+BJIH9HEUjFlXBWgrv n/n+JMTmSZxOs9KJI+mi4PhN8MoQfka95bZ6JuNA= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-98845: tpm: Disable TPM on null key name mismatch Date: Sun, 18 Oct 2026 17:47:00 +0200 Message-ID: <2026101833-CVE-2026-98845-8c19@gregkh> X-Mailer: git-send-email 2.56.0 Reply-To: , Precedence: bulk X-Mailing-List: linux-cve-announce@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3856; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=J38yYFnsNhnnB1UpwNuTqwLzN9S06jHQbL7oYEy+Sok=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlXXiY+nRfkPfG3iKuOxa/5IkfUDAL0e/L3rHT5cL3H0 q48get5RywLgyATg6yYIsuXbTxH91ccUvQytD0NM4eVCWQIAxenAEzEYBLD/OR4PRfbft73LP++ zLhm7M124YWAA8P8AL4GGacQrfiZFe0r09PkF17iVyoFAA== X-Developer-Key: i=gregkh@linuxfoundation.org; a=openpgp; fpr=F4B60CC5BF78C2214A313DCB3147D40DDB2DFB29 Content-Transfer-Encoding: 8bit From: Greg Kroah-Hartman Description =========== In the Linux kernel, the following vulnerability has been resolved: tpm: Disable TPM on null key name mismatch The null key name check exists to protect against TPM reset attacks, so a mismatch should stop the device from serving further requests. Currently it does not disable the chip when it finds a mismatch. The mismatch is logged: tpm tpm0: null key integrity check failed but the chip keeps serving commands: / # tpm2_getcap -c properties-fixed TPM_PT_FAMILY_INDICATOR: as UINT32: 0x08322e3000 as string: "2.0" ... tpm2_load_null() where the null key name check is run sets the chip as disabled only if the rc is non zero. When the mismatch is seen, rc is zero at that point and it returns success. The other issue is that the caller expects the null key handle to be populated when the function returns 0 which it does here without writing the handle and proceeds assuming the null key handle is valid. During the test, I noticed that tpm2_start_auth_session() uses the uninitialized stack value as the key handle since tpm2_load_null() returns 0 despite the integrity failure and proceeds with TPM2_CC_START_AUTH_SESS with this value as salt key handle. Set rc to -ENODEV on the mismatch. The error path then disables the chip and returns the correct code to the caller. Tested in QEMU with swtpm and CONFIG_TCG_TPM2_HMAC=y by making TPM2_CC_CONTEXT_LOAD fail with TPM2_RC_INTEGRITY and changing the name of the re-created null key. The chip is now disabled on the mismatch. The Linux kernel CVE team has assigned CVE-2026-98845 to this issue. Affected and fixed versions =========================== Issue introduced in 6.12 with commit cc7d8594342a25693d40fe96f97e5c6c29ee609c and fixed in 6.12.113 with commit a03d0c64cd827a622578623a78defd66b6593b82 Issue introduced in 6.12 with commit cc7d8594342a25693d40fe96f97e5c6c29ee609c and fixed in 6.18.56 with commit 96c46c75b0d470b4204f9fe1bdb075cd2ebaebfa Issue introduced in 6.12 with commit cc7d8594342a25693d40fe96f97e5c6c29ee609c and fixed in 7.2.10 with commit f6599d8830fe7ddab7334cc17846fd9ac9a7fa50 Issue introduced in 6.12 with commit cc7d8594342a25693d40fe96f97e5c6c29ee609c and fixed in 7.3-rc6 with commit 015fb29a748342a186f37b602ac70017098c8251 Issue introduced in 6.11.7 with commit 294984ce51c19c2af3d0d71e1c8bd589bc86b8e2 Issue introduced in 6.11.10 with commit 386c7cc6c06d64cbf36d15c5e2319814765e107c Please see https://www.kernel.org for a full list of currently supported kernel versions by the kernel community. Unaffected versions might change over time as fixes are backported to older supported kernel versions. The official CVE entry at https://cve.org/CVERecord/?id=CVE-2026-98845 will be updated if fixes are backported, please check that for the most up to date information about this issue. Affected files ============== The file(s) affected by this issue are: drivers/char/tpm/tpm2-sessions.c Mitigation ========== The Linux kernel CVE team recommends that you update to the latest stable kernel version for this, and many other bugfixes. Individual changes are never tested alone, but rather are part of a larger kernel release. Cherry-picking individual commits is not recommended or supported by the Linux kernel community at all. If however, updating to the latest release is impossible, the individual changes to resolve this issue can be found at these commits: https://git.kernel.org/stable/c/a03d0c64cd827a622578623a78defd66b6593b82 https://git.kernel.org/stable/c/96c46c75b0d470b4204f9fe1bdb075cd2ebaebfa https://git.kernel.org/stable/c/f6599d8830fe7ddab7334cc17846fd9ac9a7fa50 https://git.kernel.org/stable/c/015fb29a748342a186f37b602ac70017098c8251