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 4F5D045FFB4; Mon, 31 Aug 2026 13:45:12 +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=1788183914; cv=none; b=RMzl2S2LbvWdNukvs6lgvtXdngn3YJZHe9UUo3VkLTfKBfNWzZva3m9hvrRgXchLQKmX4nEDw1jh8/3FcufXt2oB4XeNqSad2oTP2ZtaF9W8hfFrUich+yugwi3zLqYvfYhTkgvx9FzwtStPvFYmfMqi4rE2HcZcL9mySnHuXJ4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788183914; c=relaxed/simple; bh=6IPylq5SMf7g1tYC2y1h87AxhYxyFueQTOqGTvjsmA0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ApViMXeypnFpuMKueHYsMQ+eKypa9D+WDe5OoLe3u8Oz6d5g32sbBN6C3TMrt/+RraY20hi/CVpFnR9cZeFCajOZjLgD6/t5QlsBNF92lHrlUo62N92NAcBNXZvJWD60pZPEo5UBBucxjz2lmTxne3E8Q27Y9IP6W8w+ojd8QVA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=KYPpk+qK; 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="KYPpk+qK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A83F21F00ACA; Mon, 31 Aug 2026 13:45:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788183912; bh=esc0gNEbs/3vkvJNfGjs74pWlyWujs3gszdiKF0v5TA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=KYPpk+qK/JmvYG0HWCCff4E4SR+Vg6MW5Jqq5MN4IbU9rlkX719UJoesjgVrOAjlY J8imyGZb7HrdrmWLoUTw4XsmiXdy3Hnxm8ciDpLQrSepMvewfx904tLArdZ4A0oWvE 0xuFr6NeunUBfddOOsifUj80hn9uC9Tdtd4SsIxA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Zhu Yanjun , Ibrahim Hashimov , Leon Romanovsky , Sasha Levin Subject: [PATCH 6.18 01/83] RDMA/rxe: Fix responder UAF on IB_QP_MAX_DEST_RD_ATOMIC modify_qp Date: Mon, 31 Aug 2026 15:33:37 +0200 Message-ID: <20260831133359.278435374@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260831133359.207714926@linuxfoundation.org> References: <20260831133359.207714926@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 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ibrahim Hashimov [ Upstream commit 6f7014237405e7f032b5c53a82d9eccf6161c291 ] rxe_qp_from_attr() handles IB_QP_MAX_DEST_RD_ATOMIC outside the IB_QP_STATE path, so it holds no state_lock and runs while the responder task rxe_receiver() (recv_task on rxe_wq) is live. A modify_qp() setting only that attribute calls free_rd_atomic_resources() then alloc_rd_atomic_resources(), swapping qp->resp.resources[] while rxe_prepare_res()/find_resource() walk it; free_rd_atomic_resources() also leaves the cached pointer qp->resp.res dangling. A local unprivileged user can race the free/realloc into a use-after-free in rxe_receiver() (local DoS). Drain recv_task around the swap with rxe_disable_task()/rxe_enable_task(), as rxe_qp_reset() already does when tearing this array down, re-enabling only after alloc_rd_atomic_resources() succeeds so the responder never resumes against a NULL qp->resp.resources on the ENOMEM path. Also clear qp->resp.res in free_rd_atomic_resources(), like the rxe_resp.c completion paths. Reproduced under KASAN; the slab-use-after-free in rxe_receiver() is gone. Fixes: 8700e3e7c485 ("Soft RoCE driver") Reviewed-by: Zhu Yanjun Signed-off-by: Ibrahim Hashimov Link: https://patch.msgid.link/20260712121720.78001-1-security@auditcode.ai Assisted-by: AuditCode-AI:2026.07 Signed-off-by: Leon Romanovsky Signed-off-by: Sasha Levin --- drivers/infiniband/sw/rxe/rxe_qp.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/drivers/infiniband/sw/rxe/rxe_qp.c b/drivers/infiniband/sw/rxe/rxe_qp.c index 95f1c1c2949de..0af697c6469db 100644 --- a/drivers/infiniband/sw/rxe/rxe_qp.c +++ b/drivers/infiniband/sw/rxe/rxe_qp.c @@ -124,6 +124,7 @@ static void free_rd_atomic_resources(struct rxe_qp *qp) } kfree(qp->resp.resources); qp->resp.resources = NULL; + qp->resp.res = NULL; } } @@ -660,11 +661,23 @@ int rxe_qp_from_attr(struct rxe_qp *qp, struct ib_qp_attr *attr, int mask, qp->attr.max_dest_rd_atomic = max_dest_rd_atomic; + /* + * Not gated by IB_QP_STATE, so the responder task is live. + * Quiesce recv_task like rxe_qp_reset() before swapping the + * rd_atomic array, so rxe_receiver() cannot race the free/ + * realloc. + */ + rxe_disable_task(&qp->recv_task); free_rd_atomic_resources(qp); - err = alloc_rd_atomic_resources(qp, max_dest_rd_atomic); + /* + * On ENOMEM leave recv_task quiesced: qp->resp.resources is + * NULL and rxe_prepare_res()/find_resource() would deref it. + * Re-enable only after a fresh array is installed. + */ if (err) return err; + rxe_enable_task(&qp->recv_task); } if (mask & IB_QP_EN_SQD_ASYNC_NOTIFY) -- 2.53.0