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 DCBF6330D35 for ; Fri, 4 Sep 2026 15:16:29 +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=1788534995; cv=none; b=Plnsr+10DDdjXQKmlhG8hhmn3nKijmfdpQ2EPKd3YQovMm1w7UK5QA1L2W28XasTTkkZz/uPa0bdlOiEyXLnud0bfgsxIazfcIiqGyiQu2tKMzOeXxuLkfA0u/GZD9B++7nbwrkZFzzWyeDc0we2bXGtHQH+hUiR5q6hKZoxgMM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788534995; c=relaxed/simple; bh=CdvLoh9uLw/fjoid7rXAiPD5R0ZjS4W+4X9ocYIXXRA=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=AoxObvp/GmLtQEk7TorIHGxDiP/fpzgtoRPg6cJQRm3nyAeNDg6+AjgemsFcgGbFLVljkK19aK47kHxX99ZdTjXXFIDttoL5164kXh3ngjz/GrfMlhjrVAYBg9TbxQ9Q9XRd2CVTqNjJJy1QCPNUFX8deEuwMSXMtBQcVOwvgms= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=MqZAdCnW; 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="MqZAdCnW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EB39B1F00A3D; Fri, 4 Sep 2026 15:16:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788534989; bh=8dRUaZpeVTrYtBAr3cVROugOJdYW0jX10PwbPvL59xY=; h=From:To:Cc:Subject:Date:Reply-To; b=MqZAdCnWEuivInuaI+mHSqET585zSzYWRp/14eOk5faSuzybt0XsmkMK+jdcwK4z2 waYz8u1MrYcBTGjmJzc+x28py286f+6ZOKLJbjWhmeu/XtA1T7qEkiZl124vqFlo79 BcCF2KyVKUTsL6trtklI+FPobYT5JREuBU9OrnTE= From: Greg Kroah-Hartman To: linux-cve-announce@vger.kernel.org Cc: Greg Kroah-Hartman Subject: CVE-2026-80789: nvmet-tcp: bound SGL data length before allocating command buffers Date: Fri, 4 Sep 2026 17:11:28 +0200 Message-ID: <2026090406-CVE-2026-80789-d7be@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=5471; i=gregkh@linuxfoundation.org; h=from:subject:message-id; bh=RhY9dcUlN/D4tct88blXs+xLzAR6X2Bi7mIJiWAS974=; b=owGbwMvMwCRo6H6F97bub03G02pJDFmz7nfJ1CmEfcntO3r835PGzLPtq2e2TtLxXbRqgdu+q tmzj/qc7IhlYRBkYpAVU2T5so3n6P6KQ4pehranYeawMoEMYeDiFICJmM1lWLC5u1xxuZnDV7FP 60vPOD8yUWPzrGJY0K6rk9V/2CRxcu7t7E/SV4M54neuBwA= 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: nvmet-tcp: bound SGL data length before allocating command buffers nvmet_tcp_map_data() reads the host-controlled 32-bit sgl->length and, for the in-capsule offset descriptor (type 0x01), checks it against port->inline_data_size before use. Any other SGL descriptor type -- including the non-inline transport SGL data-block descriptor (type (NVME_TRANSPORT_SGL_DATA_DESC << 4) | NVME_SGL_FMT_TRANSPORT_A, the type a real host uses for out-of-capsule writes) skips that check entirely and falls straight through to: cmd->req.sg = sgl_alloc(len, GFP_KERNEL, &cmd->req.sg_cnt); with len taken directly from the wire, unbounded up to 4 GiB. nvmet_req_init() only parses the command and never inspects sgl->length, and nvmet_check_transfer_len() -- the only other place transfer_len is validated -- runs later, from req->execute(), after the allocation has already happened. For a write command the target responds with an R2T and parks the command waiting for the host to send the data; if the host (or an unauthenticated peer that simply never follows up) never does, the sgl_alloc() buffer stays resident for the life of the command. NVMe/TCP has no mandatory authentication in the default configuration, so any peer able to reach the target portal and complete a Fabrics connect can drive this with a single crafted command, repeatable across queues and connections for amplification. This is unbounded kernel memory allocation triggered by a remote, effectively unauthenticated peer. Validate len against the same NVMET_TCP_MAXH2CDATA ceiling this file already uses to bound per-PDU H2C data, for every SGL descriptor type, before doing any allocation. This closes the gap for the non-inline descriptor while leaving the existing, tighter inline_data_size check in place for the in-capsule case. Runtime-verified on a v6.19 KASAN stand: with this bound in place, a crafted write command carrying an oversized non-inline SGL length is rejected before sgl_alloc() runs, where the same request previously drove an unbounded ~256 MiB kernel allocation (up to 4 GiB) that stayed resident pending an R2T the host never satisfies. The Linux kernel CVE team has assigned CVE-2026-80789 to this issue. Affected and fixed versions =========================== Issue introduced in 5.0 with commit 872d26a391da92ed8f0c0f5cb5fef428067b7f30 and fixed in 5.10.269 with commit f6e51b09cbaa5f6f6e6a3a9dafa666f76c37aab5 Issue introduced in 5.0 with commit 872d26a391da92ed8f0c0f5cb5fef428067b7f30 and fixed in 5.15.220 with commit f63e89a0310264264923f84406dea05fe752de62 Issue introduced in 5.0 with commit 872d26a391da92ed8f0c0f5cb5fef428067b7f30 and fixed in 6.1.187 with commit 0952541b153e258b99d39cdb03ea6919fdeb41d0 Issue introduced in 5.0 with commit 872d26a391da92ed8f0c0f5cb5fef428067b7f30 and fixed in 6.6.156 with commit 25ad03d5c0e858c4b63f1e4b6d461d2af1b30b22 Issue introduced in 5.0 with commit 872d26a391da92ed8f0c0f5cb5fef428067b7f30 and fixed in 6.12.106 with commit d2acc96c528d589f5827cfb90e8e9229dd9d8cb4 Issue introduced in 5.0 with commit 872d26a391da92ed8f0c0f5cb5fef428067b7f30 and fixed in 6.18.47 with commit 6d27199ebe8cb223022150f74be13f154a964474 Issue introduced in 5.0 with commit 872d26a391da92ed8f0c0f5cb5fef428067b7f30 and fixed in 7.1.11 with commit 14dbe37681a6a7e346fc147bb363ec7cca3180a0 Issue introduced in 5.0 with commit 872d26a391da92ed8f0c0f5cb5fef428067b7f30 and fixed in 7.2.1 with commit d895e66628f939edbb98608f6e033d3d39e6e546 Issue introduced in 5.0 with commit 872d26a391da92ed8f0c0f5cb5fef428067b7f30 and fixed in 7.3-rc1 with commit 4a3f00262a044e8e15064b1a6860968bf0500bf4 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-2026-80789 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/nvme/target/tcp.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/f6e51b09cbaa5f6f6e6a3a9dafa666f76c37aab5 https://git.kernel.org/stable/c/f63e89a0310264264923f84406dea05fe752de62 https://git.kernel.org/stable/c/0952541b153e258b99d39cdb03ea6919fdeb41d0 https://git.kernel.org/stable/c/25ad03d5c0e858c4b63f1e4b6d461d2af1b30b22 https://git.kernel.org/stable/c/d2acc96c528d589f5827cfb90e8e9229dd9d8cb4 https://git.kernel.org/stable/c/6d27199ebe8cb223022150f74be13f154a964474 https://git.kernel.org/stable/c/14dbe37681a6a7e346fc147bb363ec7cca3180a0 https://git.kernel.org/stable/c/d895e66628f939edbb98608f6e033d3d39e6e546 https://git.kernel.org/stable/c/4a3f00262a044e8e15064b1a6860968bf0500bf4