From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Jia-Ju Bai , Doug Ledford , Sasha Levin Subject: [PATCH AUTOSEL 4.9 17/98] rxe: Fix a sleep-in-atomic bug in post_one_send Date: Thu, 25 Oct 2018 10:13:02 -0400 Message-Id: <20181025141423.213774-17-sashal@kernel.org> In-Reply-To: <20181025141423.213774-1-sashal@kernel.org> References: <20181025141423.213774-1-sashal@kernel.org> List-ID: From: Jia-Ju Bai [ Upstream commit 07d432bb97f19dd5e784175152f9fce3b2646133 ] The driver may sleep under a spin lock, and the function call path is: post_one_send (acquire the lock by spin_lock_irqsave) init_send_wqe copy_from_user --> may sleep There is no flow that makes "qp->is_user" true, and copy_from_user may cause bug when a non-user pointer is used. So the lines of copy_from_user and check of "qp->is_user" are removed. Signed-off-by: Jia-Ju Bai Reviewed-by: Leon Romanovsky Acked-by: Moni Shoua Signed-off-by: Doug Ledford Signed-off-by: Sasha Levin --- drivers/infiniband/sw/rxe/rxe_verbs.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c b/drivers/infiniband/sw/rxe/rxe_verbs.c index ced416f5dffb..ef13082d6ca1 100644 --- a/drivers/infiniband/sw/rxe/rxe_verbs.c +++ b/drivers/infiniband/sw/rxe/rxe_verbs.c @@ -729,13 +729,8 @@ static int init_send_wqe(struct rxe_qp *qp, struct ib_send_wr *ibwr, sge = ibwr->sg_list; for (i = 0; i < num_sge; i++, sge++) { - if (qp->is_user && copy_from_user(p, (__user void *) - (uintptr_t)sge->addr, sge->length)) - return -EFAULT; - - else if (!qp->is_user) - memcpy(p, (void *)(uintptr_t)sge->addr, - sge->length); + memcpy(p, (void *)(uintptr_t)sge->addr, + sge->length); p += sge->length; } -- 2.17.1