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 5B614563299; Wed, 9 Sep 2026 13:54:33 +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=1788962074; cv=none; b=IHf1KRo7HFFSx+YzCQB20CSjJf3xfkfqPGCVTy5wXpKaSlIA/C/DscyEkcDl5ZyIN1ne35OhfSBsOqjsB1pAZL59TaJBfXlkG8duLdcoLYsfD10z/ek737UxWmgyJcAfFt+a1jDmGo0lOi9yTbOoLodpB/u+9HRdEycSGq+Wzqg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788962074; c=relaxed/simple; bh=ZBBb0K9fOk0ByD/iP9xRNDnpzTGg3t84cW6nTqP+7NY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=UrO/npl9eT/60fNy4iO3r1CaJszwP0Bu7Syq+1R6SG79r3uRZaTsFzvDtRU+BNtrEPxgRrN+5ltmJEImMRRlVodowqaK7gdMgTOwCKpm7bb4IRNw+oKU7CNXAgThZG3jt7jZY5vSbqH7AhzsUeMLaLWFJCWJDR+3OBreGVfU7mc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=jolSEJaw; 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="jolSEJaw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B57F21F00A3A; Wed, 9 Sep 2026 13:54:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788962073; bh=frbVhRGqbeJUcvk65114fBx14IYT/33k5kYBL90ScvE=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=jolSEJawhaqpOkTf9kB2BYNv1W/vc9jzf+U5zYknktsjjvEKQ5hL8KBX+pMONeiJT BGolVIpYvQQqSYTngdrRPlUv3N0VqEOgT66G4JjGKQcEQGYQRc+zJGpnwhOL7GCWK+ s/qj7jHkhKQyXOli/64A43ISUjo34E8GnQsYjLHg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Shivam Kumar , Sagi Grimberg , Keith Busch Subject: [PATCH 7.2 162/556] nvmet-tcp: fix out-of-bounds write when receiving an over-long PDU Date: Wed, 9 Sep 2026 15:37:22 +0200 Message-ID: <20260909134236.120523888@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260909134230.441546314@linuxfoundation.org> References: <20260909134230.441546314@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Shivam Kumar commit 14cc5a7e77731497d5bea70f3bb05df7eda982e4 upstream. nvmet_tcp_try_recv_pdu() reads a PDU header into the fixed 128-byte queue->pdu union, then computes the remaining payload length as queue->left = hdr->hlen - queue->offset + hdgst; and reads that many more bytes into &queue->pdu + queue->offset, without ever bounding the result against sizeof(queue->pdu). A struct nvme_tcp_icreq_pdu is itself 128 bytes, exactly the size of the union. Once a header digest has been negotiated (hdgst = 4), a second ICReq passes the hlen == nvmet_tcp_pdu_size() check but yields queue->left = 128 - 8 + 4 = 124, so bytes 8..132 are written into the 128-byte buffer -- 4 bytes past its end, over queue->hdr_digest and queue->data_digest. Those bytes are attacker-controlled (an ICReq carries no digest), and the duplicate ICReq is only rejected later, after the overflow. A remote unauthenticated host can thus corrupt kernel memory adjacent to the receive buffer. Reject any PDU whose declared length would read past the end of queue->pdu before the second recv. Fixes: 872d26a391da ("nvmet-tcp: add NVMe over TCP target driver") Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Shivam Kumar Cc: stable@vger.kernel.org Reviewed-by: Sagi Grimberg Signed-off-by: Keith Busch Signed-off-by: Greg Kroah-Hartman --- drivers/nvme/target/tcp.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/nvme/target/tcp.c +++ b/drivers/nvme/target/tcp.c @@ -1244,6 +1244,8 @@ recv: } queue->left = hdr->hlen - queue->offset + hdgst; + if (queue->left > sizeof(queue->pdu) - queue->offset) + return -EPROTO; goto recv; }