From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+dcfd344365a56fbebd0f@syzkaller.appspotmail.com, Leon Romanovsky , Sean Hefty , Jason Gunthorpe Subject: [PATCH 4.4 31/72] RDMA/ucma: Fix use-after-free access in ucma_close Date: Fri, 6 Apr 2018 15:23:32 +0200 Message-Id: <20180406084307.774007716@linuxfoundation.org> In-Reply-To: <20180406084305.210085169@linuxfoundation.org> References: <20180406084305.210085169@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Leon Romanovsky commit ed65a4dc22083e73bac599ded6a262318cad7baf upstream. The error in ucma_create_id() left ctx in the list of contexts belong to ucma file descriptor. The attempt to close this file descriptor causes to use-after-free accesses while iterating over such list. Fixes: 75216638572f ("RDMA/cma: Export rdma cm interface to userspace") Reported-by: Signed-off-by: Leon Romanovsky Reviewed-by: Sean Hefty Signed-off-by: Jason Gunthorpe Signed-off-by: Greg Kroah-Hartman --- drivers/infiniband/core/ucma.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/infiniband/core/ucma.c +++ b/drivers/infiniband/core/ucma.c @@ -494,6 +494,9 @@ err1: mutex_lock(&mut); idr_remove(&ctx_idr, ctx->id); mutex_unlock(&mut); + mutex_lock(&file->mut); + list_del(&ctx->list); + mutex_unlock(&file->mut); kfree(ctx); return ret; }