From 32cd87f54dd1070020e664ccb0312a9f0fea79b4 Mon Sep 17 00:00:00 2001 From: Guoqing Jiang Date: Thu, 27 Aug 2026 20:55:53 +0800 Subject: [PATCH] RDMA/siw: Clear association under lock if siw_qp_modify fails in siw_accept 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. Fixes: 6c52fdc244b5 ("rdma/siw: connection management") 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 Link: https://patch.msgid.link/20260827125553.12831-1-guoqing.jiang@linux.dev Acked-by: Bernard Metzler Signed-off-by: Leon Romanovsky --- 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);