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 C9DA44E8E17 for ; Fri, 4 Sep 2026 15:17:20 +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=1788535042; cv=none; b=oBSg7NccZDdHnAJvdzUNTgmk2g/oQiv/GccnISkmTeQTwxNn7JqZskJ5REfL123FhZYa4QAJBfcDVU6uWWVjAn9WoJ8D5pfALT+JKsi1+HPSVtjCiJIbKPPEBt42EsLPVhuNPhFJvY9vsNqT9C9TV6z93Psu6iNzeZ8BxcktcL8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788535042; c=relaxed/simple; bh=KLjhUaD68wBUD0XmWNe4a6cFeYMfD2ilIghCpsXG0p8=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=l89qcxxGKX9V/tWFFFIO91akrj3+q2Q+HmItH1fBHOVHXx2LM8R8t7ZHE0K9YC7GItZiNZ8vvlnnyB426BFhDZmMPTuklyhVCIm0A41RwGtBpIo2OV7FTtsZ/kxxcrRQbs/3csjdBCRoNfT4abnMCLTtmDW81eNk03MUEKA/FH8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=IIXbigtl; 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="IIXbigtl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1AD151F00A3D; Fri, 4 Sep 2026 15:17:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788535039; bh=hxyFvVNngt6cWl55i0xuCShOG22MiawyJEFiKrPtyWk=; h=From:To:Cc:Subject:Date:Reply-To; b=IIXbigtl4fIwmFi1a5NskaNmdLRSMsQ2KGEUxJ6hdQ2Yuj+w17Xq19pEyes8Hm9nZ xIEf8C5KO50uReX0eF0lZo73W7ZYyZ5QidHrNw7gFJIHmhbOnwdKyIYUojSqNk+/0n IWFFi3mP3oy5Cva/RtP70GHGYq6LAx/cjIAIvF9k= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-80758: futex: Avoid private hash use-after-free on final put Date: Fri, 4 Sep 2026 17:10:57 +0200 Message-ID: <2026090456-CVE-2026-80758-8292@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=3045; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=uzIw05jppnk2jF2sQkl+2JlKMaimWmaz1jV6nkKXIYs=; b=owGbwMvMwCRo6H6F97bub03G02pJDFmz7jc8nTZPPa3xc8Y9NUsZ6dqvGTwzZokl3XoyxcP3j efCV3pdHbEsDIJMDLJiiixftvEc3V9xSNHL0PY0zBxWJpAhDFycAjCR87wMCw7OYvrhv7hOpnFi sfTDhP4meYbuJQzzs035Z1x98iRMdc/Ts8oz/6c/WGTXDAA= 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: futex: Avoid private hash use-after-free on final put futex_private_hash_put() drops the reference to fph before evaluating fph->mm for wake_up_var(). futex_ref_put() enables preemption again before returning. If that put drops the final reference and the task is preempted, another task can pivot to the replacement hash and free the old hash after an RCU grace period. The first task then reads fph->mm from the freed allocation when it resumes. KASAN reports a slab-use-after-free in futex_private_hash_put(), with the read at offset 24 in a freed kmalloc-512 allocation. The allocation and free stacks point to futex_hash_allocate() and the RCU free path, respectively. Load the mm pointer while the fph reference is still held and pass the saved value to wake_up_var(). wake_up_var() uses the pointer as a waitqueue key and does not dereference the mm through it. The Linux kernel CVE team has assigned CVE-2026-80758 to this issue. Affected and fixed versions =========================== Issue introduced in 6.16 with commit bd54df5ea7cadac520e346d5f0fe5d58e635b6ba and fixed in 6.18.47 with commit dba60d26e9dda3e157ad6b0934d4232f6c6904ee Issue introduced in 6.16 with commit bd54df5ea7cadac520e346d5f0fe5d58e635b6ba and fixed in 7.1.11 with commit 12cd315a7b6a7d7db3f69d98bfe3909275e9451d Issue introduced in 6.16 with commit bd54df5ea7cadac520e346d5f0fe5d58e635b6ba and fixed in 7.2.1 with commit 25408c62ed4ebcd491d0e9e4b4a5b512547512e4 Issue introduced in 6.16 with commit bd54df5ea7cadac520e346d5f0fe5d58e635b6ba and fixed in 7.3-rc1 with commit 1c7efabfbaf796f11000a46094a69955a01ec6cc 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-2026-80758 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: kernel/futex/core.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/dba60d26e9dda3e157ad6b0934d4232f6c6904ee https://git.kernel.org/stable/c/12cd315a7b6a7d7db3f69d98bfe3909275e9451d https://git.kernel.org/stable/c/25408c62ed4ebcd491d0e9e4b4a5b512547512e4 https://git.kernel.org/stable/c/1c7efabfbaf796f11000a46094a69955a01ec6cc