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 054A74E9C1C for ; Thu, 17 Sep 2026 16:36:45 +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=1789663007; cv=none; b=bJQiOnMzQxGEoCGrrdcUoBy7m8SmRGAsexRzNbswC8mL+Sx+37cTZsbmP9mR6EdO68jxx+e4AniDslWP1EdYZMXcdrVG7vW5voMb+K/DMp08A7MZ1b0TWuAeni7uQZS+0xa49vFKh9r3m7A7BzxMogNC4+mYUUZJblj2vNamM1E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789663007; c=relaxed/simple; bh=YyVq2QUInK2LrXYXfkatlmTuX5qL+XzY474MUA/dMbg=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=b3UTtTM6TZvodWwGE+iGxzhUKdT6SiyDlWGuwyZE6v59mrdigOK4DxYLhkbTyGzJDOay4H0UZ3T+BeEg+tdtmqDtOWGxKGeF/S0SVPtcMA5WHSqYacGCl/Yy0T5NdprVlCa/GzNVa8c+mNIlMsYZUIM3OtaeD5WxRGMScuR5w2o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=yj0sEKet; 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="yj0sEKet" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0BCA81F00899; Thu, 17 Sep 2026 16:36:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789663005; bh=7bL6BqIIoTJRCJrhQ3fx+TALUV1DfE5pdEy7hY9f5Yc=; h=From:To:Cc:Subject:Date:Reply-To; b=yj0sEKeta4AkjhQcLudyf042rpaikRXbpvoXw2HLOdaVY/Xrirzxmi5T5j+maKke8 clJ69YRmWxtjlQi7nncf+diWqCJGOxLBFkZqex4VGeGSVRctM0/Nb8RGq331gbfh6b 9d8DsGt3vZWSac/kfN2QEoDb1p7NM20b4QuIN3/w= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-93096: cxl/features: Serialize multi-part Get/Set Feature transfers Date: Thu, 17 Sep 2026 17:16:13 +0100 Message-ID: <2026091744-CVE-2026-93096-47bc@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=2618; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=6AFafJ2XyvxuejbGQIJgmRzVsMPqPSf9+eOWuHweVME=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlrBE78OBF0rejjw883v/5Y+khIgCWr3KXp6pGF18RiQ oMn2zVf7YhlYRBkYpAVU2T5so3n6P6KQ4pehranYeawMoEMYeDiFICJeHEzLDg9I7c2LUJ8Vs37 r75KT5sf+pvVbGaYX1e546dYCKtyiMVugxM8Thoti7WvAAA= 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: cxl/features: Serialize multi-part Get/Set Feature transfers A Get or Set Feature payload larger than the mailbox payload size is split into several mailbox commands. mbox_mutex only serializes individual mailbox commands and is dropped between iterations of these loops. Nothing serializes the multi-part transfer as a whole. cxl_get_feature() and cxl_set_feature() are reachable concurrently from fwctl (per-fd RPCs run under a read-held registration lock) and from the EDAC scrub/ECS/repair paths, so two transfers to the same mailbox can interleave their parts and corrupt the device's transfer context. Add a per-mailbox feat_mutex and hold it across the whole transfer in both functions. It nests outside mbox_mutex (which is taken inside cxl_internal_send_cmd()), and is taken nowhere else, so no lock-ordering inversion is introduced. The Linux kernel CVE team has assigned CVE-2026-93096 to this issue. Affected and fixed versions =========================== Issue introduced in 6.15 with commit 5e5ac21f629de796ab5d598b59c5e468c6fe4f95 and fixed in 7.2.6 with commit 7682b617db1f19bc606b5f1badadcf1e63a87b14 Issue introduced in 6.15 with commit 5e5ac21f629de796ab5d598b59c5e468c6fe4f95 and fixed in 7.3-rc1 with commit 77b814c1832fde018c30357b4ec3fcdaa91a1c10 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-2026-93096 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/cxl/core/features.c drivers/cxl/core/mbox.c include/cxl/mailbox.h 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/7682b617db1f19bc606b5f1badadcf1e63a87b14 https://git.kernel.org/stable/c/77b814c1832fde018c30357b4ec3fcdaa91a1c10