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 CEED433A029 for ; Sat, 25 Jul 2026 08:51:59 +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=1784969520; cv=none; b=h1Ycfm6rGpnalYMIj1KaWGDH0gHYMtwEM9SP/MAbJOpWmHM0ZVPsGWuq7IzzbRWaZiE10XI9W1G3PC7gLwRHttwjeJsIbYnJkGJbh19vvpxyAI1QBfRkcabtTy/quQ4/OqexG2DVWJ90A+SlEGbb1t8cnXnshq3kHx0RPlE1Or4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784969520; c=relaxed/simple; bh=6uPeQmfFxIWBTc+RzNprTpS4imJNEoGhxUI87sCqJ7w=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=mp0zcxBrQwBxFgQdW9oVT50DAJNcINg8usUG5bFzb4Rku/ENkfrhfkxLyWX5aZB461wR2/uHQs91MAdBJFyGL95349+CcwtsoTZiDdC2ixuhlwEv7DTs8i4yObzUuhIvNi056rwGXs4HsX9EIkTfoh+ODj3Ju6cVBv1bOl02JXc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Dx1i8aYQ; 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="Dx1i8aYQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3D3221F000E9; Sat, 25 Jul 2026 08:51:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784969519; bh=Jv2uMzXP46KhongidXz4H2Spxd1kM6hu9CQRaZZ6FvA=; h=From:To:Cc:Subject:Date:Reply-To; b=Dx1i8aYQEPnU9CfWfKTPIb44uKCM74dzTwXIvS0frB0vZpdzBplA9lVnC2KxDlWhy 2lpw7YrEjgauyscE/BMPgbRnPqNfOg+p8IKtJpfCPcfmvfuG28eSl+361A/3vbv98Q YIkOIs1qj3sxEDvIxGjNeyQ7xGpBoksmNhrXAp5U= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-64264: fuse-uring: fix EFAULT clobber in fuse_uring_commit Date: Sat, 25 Jul 2026 10:48:01 +0200 Message-ID: <2026072558-CVE-2026-64264-edde@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=3094; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=XbHuP00jsRHCyxID2bV8pNO0LWPAVZkZH8MPuBsvcCY=; b=owGbwMvMwCRo6H6F97bub03G02pJDFkpFXbTfkXvNHjF8537g/njlwuKej99bJwgtLwh3IV/d 6EHa5t3RywLgyATg6yYIsuXbTxH91ccUvQytD0NM4eVCWQIAxenAEzE4xbDfM8tHOyLXe8tuP/Z Y/Wj5X4WJfqyQQzzbDtZf73TF3xhavzLM3npzEX1AfX8AA== 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: fuse-uring: fix EFAULT clobber in fuse_uring_commit copy_from_user() returns the number of bytes not copied as an unsigned residual on failure (1..sizeof(struct fuse_out_header)). fuse_uring_commit stores that residual in ssize_t err, sets req->out.h.error to -EFAULT, then jumps to out: with err still holding the positive residual. err = copy_from_user(&req->out.h, &ent->headers->in_out, sizeof(req->out.h)); if (err) { req->out.h.error = -EFAULT; goto out; /* err is the positive residual */ } ... out: fuse_uring_req_end(ent, req, err); fuse_uring_req_end() then runs if (error) req->out.h.error = error; which overwrites the just-assigned -EFAULT with the positive residual. FUSE callers such as fuse_simple_request() test err < 0 to detect failure, so the positive value is interpreted as success and the caller proceeds with an uninitialised or partial req->out.args. Fix by assigning err = -EFAULT in the failure branch before jumping to out, so fuse_uring_req_end() receives a negative errno and sets req->out.h.error to -EFAULT. The Linux kernel CVE team has assigned CVE-2026-64264 to this issue. Affected and fixed versions =========================== Issue introduced in 6.14 with commit c090c8abae4b6b77a1bee116aa6c385456ebef96 and fixed in 6.18.39 with commit 0483fffdeeb363f320e6bf5fc0f0306007507306 Issue introduced in 6.14 with commit c090c8abae4b6b77a1bee116aa6c385456ebef96 and fixed in 7.1.4 with commit fe604c08d874648a69187f6380e5c7858627dc04 Issue introduced in 6.14 with commit c090c8abae4b6b77a1bee116aa6c385456ebef96 and fixed in 7.2-rc1 with commit 3a0a8bc51a13951c5141262bf770eeea3e0b6228 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-2026-64264 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: fs/fuse/dev_uring.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/0483fffdeeb363f320e6bf5fc0f0306007507306 https://git.kernel.org/stable/c/fe604c08d874648a69187f6380e5c7858627dc04 https://git.kernel.org/stable/c/3a0a8bc51a13951c5141262bf770eeea3e0b6228