From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mta0.migadu.com (out-233.mta0.migadu.com [91.218.175.233]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D0B8044C658 for ; Thu, 27 Aug 2026 12:56:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.233 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787835400; cv=none; b=H7Q29pP8WhpliiLYcNLRZrtLUk89sUdxfxeXJFuBte9PXbWORxUyF9jo3pCHS9Gl9x1aJyIrK2H1JFCHTBKbRnQyklNklfiRcYVfjsKZxW4QiLiHXRdcfrumX8yTHejOEZAVAw70RQ/qagl9Poj3q9SW19tWpCfI6yacrD4kfmU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787835400; c=relaxed/simple; bh=zb4rhB7Mz3MmEfbG4+wb0PrLh1sJ1yqihfZR2ime010=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=S/+Z3NE6/q06Y/7B39/S5jxvOZ/17HSiwfN2ZEH0U/Sww2jrUHtZwRtKqK4JfoNyapqNZDtQcztmhZSIL8vL4hNjOaSDkxM2U6qy/Hs3e4TeLkXL9FLZgjxEjWW2ulPrXtt9naHOtExG/CZ7gXydenYdh8KZdgBjmHYymQHonOo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=vZcnFhz5; arc=none smtp.client-ip=91.218.175.233 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="vZcnFhz5" X-Envelope-To: linux-rdma@vger.kernel.org DKIM-Signature: a=rsa-sha256; bh=zb4rhB7Mz3MmEfbG4+wb0PrLh1sJ1yqihfZR2ime010=; c=simple/simple; d=linux.dev; h=from:to:subject:date:message-id:mime-version:content-type; s=key1; t=1787835377; v=1; x=1788440177; b=vZcnFhz5sNDQ64FraBMEvc1+ZJrnMbMuK8PS6l+p3OKmkFspbRvnXJLPyOvYofCxF2Awrtja XRZBHZ0Ggqay7eSDLmuwAqWmlcuaIM46yxDMJNxoF+syFEjlEhVoWnNOCtYUx0HYpkoC1eBaJOC dcbisR0lFKEmpb3UozI5fqlQ= X-Envelope-To: linux-rdma@vger.kernel.org Received: by mta12.migadu.com with ESMTPS id 9b1669a1a0009215; Thu, 27 Aug 2026 12:56:07 +0000 X-Mizu-Trace-ID: 9b1669a1a0009215 X-Migadu-Flow: FLOW_OUT From: Guoqing Jiang To: bernard.metzler@linux.dev, jgg@ziepe.ca, leon@kernel.org Cc: linux-rdma@vger.kernel.org, shuangpeng.kernel@gmail.com Subject: [PATCH v2] RDMA/siw: Clear association under lock if siw_qp_modify fails in siw_accept Date: Thu, 27 Aug 2026 20:55:53 +0800 Message-Id: <20260827125553.12831-1-guoqing.jiang@linux.dev> X-Mailer: git-send-email 2.35.3 Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit We need to clear cep before release state_lock as siw_qp_llp_close and siw_qp_modify->siw_qp_llp_close did. Otherwise if siw_qp_modify() fails in siw_accept(), the QP's state_lock is released before the error path cleanup. A concurrent ibv_modify_qp() transitioning the QP to ERROR can race in this window: siw_accept() ibv_modify_qp(ERROR) ---------------------- ---------------------- siw_qp_modify() fails up_write(&qp->state_lock) down_write(&qp->state_lock) nextstate_from_idle(): if (qp->cep) siw_cep_put(qp->cep) <- frees cep qp->cep = NULL goto error cep->qp = NULL <- UAF Clear qp->cep and drop the association reference taken by siw_cep_get(), all under the write lock held from the initial down_write(&qp->state_lock). Thread B therefore sees qp->cep == NULL, skips its own put, and cannot free the cep before siw_accept() is done with it. Reported-by: Shuangpeng Bai Link: https://lore.kernel.org/linux-rdma/d6fbe475-a5c2-f975-99b0-a0bd6b6d10e8@linux.dev/T/#m5876c1ff2de8686a9a1173b8f1aa0ff5363a785c Signed-off-by: Guoqing Jiang --- V2: remove redundant code per Bernard's review drivers/infiniband/sw/siw/siw_cm.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/infiniband/sw/siw/siw_cm.c b/drivers/infiniband/sw/siw/siw_cm.c index 0245b25e7271..ed49818793dd 100644 --- a/drivers/infiniband/sw/siw/siw_cm.c +++ b/drivers/infiniband/sw/siw/siw_cm.c @@ -1719,9 +1719,12 @@ int siw_accept(struct iw_cm_id *id, struct iw_cm_conn_param *params) SIW_QP_ATTR_STATE | SIW_QP_ATTR_LLP_HANDLE | SIW_QP_ATTR_ORD | SIW_QP_ATTR_IRD | SIW_QP_ATTR_MPA); + if (rv) { + qp->cep = NULL; + siw_cep_put(cep); + goto error_unlock; + } up_write(&qp->state_lock); - if (rv) - goto error; siw_dbg_cep(cep, "[QP %u]: send mpa reply, %d byte pdata\n", qp_id(qp), params->private_data_len); -- 2.35.3