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 F3E4F33A9E2; Sat, 12 Sep 2026 14:25:34 +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=1789223136; cv=none; b=b2U+S68bbIOUsIx03TpKIrc+gI7rxWbmv6e8/I5VCcxTj//GZb6hJT0Z6Z52fvrTCOV/ZXHkwKuxPkuaYn+L+nB3QonHH1jdyZel2FM0nrZPj7nH1OYkAc3zjLyj2E5KBCgOiVqN8XsJqLrlVNx7uGRn6dlunlmFDah8sMjd3s8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789223136; c=relaxed/simple; bh=o7aTIu6k2fSjAFLWB8aPQyzt7ZhEvl0LkETe9XwdKxc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=J2BCSSqxmGym9stjDwilVKsS2hXNUZBGPkXD7a0DDJpLRYLTNVzafvgzg6hksGu9eKV5BFBbhp7Zo0t1e66tumzXuTpacz4evrK8rDs/LWEj3blGpItOwayXql+0y1j3SQ76L4fb02NmVUazNWBBWMw2qF9kc3JnOlLbotYDXy8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=g4mZZnjH; 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="g4mZZnjH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EEC331F000FF; Sat, 12 Sep 2026 14:25:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789223134; bh=e9GMD3NzBqEw6wpemsCusFOwcf7G7Sf2wXiBNC+z6LM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=g4mZZnjHFuqE8AZ7RF79fqFSCByfLegjCrMVX8nr39yt3jrikC/uTDYhSrTZvrIOy nip1YtTuNAnHLub49RSb+ECh8WIcJJUvvxpg4UGmfqlCSQ47LmpULJCm30i1oXjLP8 kUoEGL7PHKOiiLGFMzqRkW94GGzVTDFA10qRMxdE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Allison Henderson , Zhu Yanjun , Leon Romanovsky , Sasha Levin Subject: [PATCH 6.6 0721/1424] RDMA/rxe: Avoid reprocessing the current packet after the QP enters the error state Date: Sat, 12 Sep 2026 08:52:33 +0200 Message-ID: <20260912065623.438584498@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065607.279695368@linuxfoundation.org> References: <20260912065607.279695368@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 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Allison Henderson [ Upstream commit 15ae32c4a3551c4c9da457370bdfdd65d171e512 ] When do_complete() finds the QP in the error state it returns RESPST_CHK_RESOURCE. Before commit 49dc9c1f0c7e ("RDMA/rxe: Cleanup reset state handling in rxe_resp.c") this was the flush loop: check_resource() had an error-state branch that fetched each remaining recv WQE and completed it with IB_WC_WR_FLUSH_ERR, without touching the current packet. That commit removed the error-state branch from check_resource() (draining is now done at rxe_receiver() entry) but kept the do_complete() error-state return. As a result, when a QP moves to the error state while a packet is being completed - e.g. an rdma_cm disconnect racing with receive processing - the responder state machine loops back into the request processing chain with the already-completed packet still in hand: check_resource() fetches a fresh recv WQE, execute()/send_data_in() copies the same packet payload again, do_complete() posts another IB_WC_SUCCESS CQE (qp->resp.status is still 0), and control returns to the error-state check. The loop re-executes the same packet once per posted recv WQE (observed: ~1000 duplicate IB_WC_SUCCESS completions of one SEND, one per ~8us, matching the RQ occupancy) until the RQ is exhausted, after which qp->resp.wqe is NULL and send_data_in() dereferences it: BUG: kernel NULL pointer dereference, address: 0000000000000014 Workqueue: rxe_wq do_work RIP: copy_data+0x29/0x1f0 Call Trace: send_data_in+0x25/0x50 rxe_receiver+0xf36/0x1dd0 The duplicate completions are indistinguishable from real receives to the ULP. During an rds stress test, the message was accepted as new and delivered the same datagram to user space hundreds of times, corrupting the stream; any ULP that relies on RC exactly-once delivery is affected. A live packet reaching the error-state check in do_complete() has been executed and completed exactly once and must be consumed, not re-processed. Return RESPST_CLEANUP for it (dequeue and free); keep returning RESPST_CHK_RESOURCE for the pkt == NULL case. Fixes: 49dc9c1f0c7e ("RDMA/rxe: Cleanup reset state handling in rxe_resp.c") Assisted-by: Claude-Code:claude-fable-5 Signed-off-by: Allison Henderson Link: https://patch.msgid.link/20260711165419.13486-1-achender@kernel.org Reviewed-by: Zhu Yanjun Signed-off-by: Leon Romanovsky Signed-off-by: Sasha Levin --- drivers/infiniband/sw/rxe/rxe_resp.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c index 539a30ec98219..e03082db4243a 100644 --- a/drivers/infiniband/sw/rxe/rxe_resp.c +++ b/drivers/infiniband/sw/rxe/rxe_resp.c @@ -1198,7 +1198,14 @@ static enum resp_states do_complete(struct rxe_qp *qp, spin_lock_irqsave(&qp->state_lock, flags); if (unlikely(qp_state(qp) == IB_QPS_ERR)) { spin_unlock_irqrestore(&qp->state_lock, flags); - return RESPST_CHK_RESOURCE; + /* The packet was executed and completed before the QP + * moved to ERROR; it must be consumed exactly once. + * Re-entering the request chain with the stale packet + * would copy it into every remaining recv WQE as a new + * completion. Remaining WQEs are flushed by the drain + * path at rxe_receiver() entry. + */ + return pkt ? RESPST_CLEANUP : RESPST_CHK_RESOURCE; } spin_unlock_irqrestore(&qp->state_lock, flags); -- 2.53.0