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 D258259220F for ; Fri, 11 Sep 2026 20:06:25 +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=1789157189; cv=none; b=Bh6+y8YgSX+Reo4jkJKzcT5t1/4tLD2dRvYWp+CHbf1CMvZ+Cd9JHi80Y1RnMdhTBWyFCm86cud3+XP7Dnbl25u6jSzo6FAC2CFAe6Ra17fZKw+DvIgl7477Z/gPBdCQ4/qQZBr4LX7AyQxO7dZqi/54CB/z6plQf7kcXFvWD/M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789157189; c=relaxed/simple; bh=ORQWzjHnsxKGMm4L7AuMynSXdHWvSCbyGCVx+eRDf1s=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=LnmljfRkAMF8VxoVLlbH8JsBSwt+qsmR8BnrY+J5mkH5H3AIUSNIcOpRhcukTjwxl4m7vxAF/l+ep8hFVKNPCGdcAER5nF6D6gd4ghHFpjM2A4MJPX/rzq1Qry8T2M7WVKF9+R+2f/dVn2lVFSxJKL6lHvefyt2Df9SlYCkM1eQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Ukbneu00; 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="Ukbneu00" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 496801F00893; Fri, 11 Sep 2026 20:06:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789157181; bh=FuHpykePsVhSNvMKm10E2qK73jYo6gurzcbBkczObvw=; h=From:To:Cc:Subject:Date:Reply-To; b=Ukbneu00rJg4HQIZEq+MisIqXveu7Wjju+qKOaB+TwE6ETN3ckAxrA3mVlIRzMLKc puC82B+PvetwOqD9yKqmkLP6Kun7T6XhXP/2HhjJ6nEFn/BJudd7oXas4glufxDLoX uEXXH2O+TwwE6yBzLqT9EV30eNjV0BInUk6g9dus= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-89763: KEYS: trusted: Fix TPM teardown ordering Date: Fri, 11 Sep 2026 21:47:32 +0200 Message-ID: <2026091109-CVE-2026-89763-b7a8@gregkh> X-Mailer: git-send-email 2.55.0 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=3658; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=H7mxSdgJKxGJVAUmdJJ3Tq/bZghbT1qn9YsOqY92/O8=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlLIifVucWe29IiE/Px76PYDSn/FCeqiwvcPsOneINPT PJxAVtBRywLgyATg6yYIsuXbTxH91ccUvQytD0NM4eVCWQIAxenAEwkQZVhvsc/3tCkHa6vDxcZ HL6mEu0x8fEkF4a5AlelFyWaN8xefzeW5b7ZhCAZreTJAA== 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: KEYS: trusted: Fix TPM teardown ordering 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. The Linux kernel CVE team has assigned CVE-2026-89763 to this issue. Affected and fixed versions =========================== Issue introduced in 5.1 with commit 0b6cf6b97b7ef1fa3c7fefab0cac897a1c4a3400 and fixed in 6.18.50 with commit 753c978f2400f9783eb524842a975d3ac950d511 Issue introduced in 5.1 with commit 0b6cf6b97b7ef1fa3c7fefab0cac897a1c4a3400 and fixed in 7.2.4 with commit 2f7541afbc57fe9d26769a22c31d8ce8790c9a19 Issue introduced in 5.1 with commit 0b6cf6b97b7ef1fa3c7fefab0cac897a1c4a3400 and fixed in 7.3-rc1 with commit 5e2d672280d97d83de43031d93761b12dadd7b8a 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-2026-89763 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: security/keys/trusted-keys/trusted_tpm1.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/753c978f2400f9783eb524842a975d3ac950d511 https://git.kernel.org/stable/c/2f7541afbc57fe9d26769a22c31d8ce8790c9a19 https://git.kernel.org/stable/c/5e2d672280d97d83de43031d93761b12dadd7b8a