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 0C8C355C1DA for ; Fri, 11 Sep 2026 19:56:41 +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=1789156605; cv=none; b=EFesRqhbD4vp6QrRDeJ36vhTPsYpprBQt+WC44YBFI9sULF+A5QjPPHSlrrhDPgbPKcc1zpafzgd5SCYP6cAubSqRNWHEmEYHQHY8QECuMh3RduY2S7Z87hba0opwUVh0TvhQNGssQ4mZuzPgdLw3OFQ1skxc7QSJsjUaxakl3Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789156605; c=relaxed/simple; bh=33DxIzgcw81m8cvCXx04pSO9ouOywIzKxXUo8ktNSAY=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=Ad4XDjr+deGQJhQz8z7nNR0UpNnybNvDdFz6X9tdrAVf3XOOeK6nB9LhQF7W5DduceD8p82kEXu5aLyP1GbMCdduC2mbtTWoL9wM64e5XK/RKlGrxvQRBO8q30qRi+Yst+vLbfEg5fqIl7+4QCq7QXHOWe0GYScMnCwLQAxotJU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=HDy1NaFA; 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="HDy1NaFA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A0DC01F0089C; Fri, 11 Sep 2026 19:56:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789156601; bh=vcJ0ivX66Ew/UPgt2iITPoJsTpAH4K0ixwTuMuHZC+A=; h=From:To:Cc:Subject:Date:Reply-To; b=HDy1NaFAkU/HULcz893eeaR6EaYc37numfJVfCnNUhsusQm+gT3Hfa7j/TOuiJabp Y+nXDs6fL3y6OS12qUz327z3XqBwke/9JyxVM9Qbc+XImpkvLSUJEP6LU+FxCrbxBB G9mWEDUwwiewuGIoI3GlVwpoenr13QXz1rhDZq+Q= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-89571: cxl/features: bound fwctl command payload to the input buffer Date: Fri, 11 Sep 2026 21:44:20 +0200 Message-ID: <2026091126-CVE-2026-89571-7c16@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=3005; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=9TfNsCmSKjhtzIEx9PRLE45T+PkqlW8Nw2vUjinfIBw=; b=owGbwMvMwCRo6H6F97bub03G02pJDFlLItPMgm58rl3m3GLNteXp86kPs1weL2dPWffou+5WU /7CL3vXdMSyMAgyMciKKbJ82cZzdH/FIUUvQ9vTMHNYmUCGMHBxCsBErooxzOGKYBOyvsjWlBN9 nEdr49xc8Vs+MQzzzCMkWrcVJb56vMJ1e7Zk6BVOObUpAA== 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: bound fwctl command payload to the input buffer fwctl_cmd_rpc() copies cmd->in_len bytes into inbuf = kvzalloc(cmd->in_len) and passes inbuf and in_len to ->fw_rpc(). The CXL callback cxlctl_fw_rpc() ignores in_len and never checks the user-controlled op_size against it. cxlctl_set_feature() bounds op_size only from below (op_size <= sizeof(feat_in->hdr)) and then reads op_size - sizeof(hdr) bytes from feat_in->feat_data via cxl_set_feature(). With a small in_len and a large op_size the first memcpy() already reads past the kvzalloc(in_len) buffer; the out-of-bounds bytes are placed in the mailbox payload and sent to the device, and a large enough op_size can walk into unmapped memory and oops the kernel. The Get paths pin op_size to a fixed size but likewise read the input struct without checking in_len. Reject, at the single dispatch point, any request whose fixed header plus op_size does not fit in the copied-in buffer. The lower-bound test guards the subtraction and ensures op_size was copied in before it is read. The Linux kernel CVE team has assigned CVE-2026-89571 to this issue. Affected and fixed versions =========================== Issue introduced in 6.15 with commit eb5dfcb9e36d0e46089fec777d911313c1876fa3 and fixed in 6.18.50 with commit 14d52c15d5d99477b20a2d61fe36f347080da6cd Issue introduced in 6.15 with commit eb5dfcb9e36d0e46089fec777d911313c1876fa3 and fixed in 7.2.4 with commit d8957545fe96f7905791c937758ebfc1ae1e5b17 Issue introduced in 6.15 with commit eb5dfcb9e36d0e46089fec777d911313c1876fa3 and fixed in 7.3-rc1 with commit f687394af983df5660b6afae7e0d06969f3af206 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-2026-89571 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 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/14d52c15d5d99477b20a2d61fe36f347080da6cd https://git.kernel.org/stable/c/d8957545fe96f7905791c937758ebfc1ae1e5b17 https://git.kernel.org/stable/c/f687394af983df5660b6afae7e0d06969f3af206