This is a note to let you know that I've just added the patch titled RDMA/qedr: Fix KASAN: use-after-free in ucma_event_handler+0x532 to the 5.7-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: rdma-qedr-fix-kasan-use-after-free-in-ucma_event_han.patch and it can be found in the queue-5.7 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit ca549775350cd4c4919d67b668251e42d7ecab0d Author: Michal Kalderon <michal.kalderon@xxxxxxxxxxx> Date: Tue Jun 16 12:34:08 2020 +0300 RDMA/qedr: Fix KASAN: use-after-free in ucma_event_handler+0x532 [ Upstream commit 0dfbd5ecf28cbcb81674c49d34ee97366db1be44 ] Private data passed to iwarp_cm_handler is copied for connection request / response, but ignored otherwise. If junk is passed, it is stored in the event and used later in the event processing. The driver passes an old junk pointer during connection close which leads to a use-after-free on event processing. Set private data to NULL for events that don 't have private data. BUG: KASAN: use-after-free in ucma_event_handler+0x532/0x560 [rdma_ucm] kernel: Read of size 4 at addr ffff8886caa71200 by task kworker/u128:1/5250 kernel: kernel: Workqueue: iw_cm_wq cm_work_handler [iw_cm] kernel: Call Trace: kernel: dump_stack+0x8c/0xc0 kernel: print_address_description.constprop.0+0x1b/0x210 kernel: ? ucma_event_handler+0x532/0x560 [rdma_ucm] kernel: ? ucma_event_handler+0x532/0x560 [rdma_ucm] kernel: __kasan_report.cold+0x1a/0x33 kernel: ? ucma_event_handler+0x532/0x560 [rdma_ucm] kernel: kasan_report+0xe/0x20 kernel: check_memory_region+0x130/0x1a0 kernel: memcpy+0x20/0x50 kernel: ucma_event_handler+0x532/0x560 [rdma_ucm] kernel: ? __rpc_execute+0x608/0x620 [sunrpc] kernel: cma_iw_handler+0x212/0x330 [rdma_cm] kernel: ? iw_conn_req_handler+0x6e0/0x6e0 [rdma_cm] kernel: ? enqueue_timer+0x86/0x140 kernel: ? _raw_write_lock_irq+0xd0/0xd0 kernel: cm_work_handler+0xd3d/0x1070 [iw_cm] Fixes: e411e0587e0d ("RDMA/qedr: Add iWARP connection management functions") Link: https://lore.kernel.org/r/20200616093408.17827-1-michal.kalderon@xxxxxxxxxxx Signed-off-by: Ariel Elior <ariel.elior@xxxxxxxxxxx> Signed-off-by: Michal Kalderon <michal.kalderon@xxxxxxxxxxx> Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/infiniband/hw/qedr/qedr_iw_cm.c b/drivers/infiniband/hw/qedr/qedr_iw_cm.c index 792eecd206b61..97fc7dd353b04 100644 --- a/drivers/infiniband/hw/qedr/qedr_iw_cm.c +++ b/drivers/infiniband/hw/qedr/qedr_iw_cm.c @@ -150,8 +150,17 @@ qedr_iw_issue_event(void *context, if (params->cm_info) { event.ird = params->cm_info->ird; event.ord = params->cm_info->ord; - event.private_data_len = params->cm_info->private_data_len; - event.private_data = (void *)params->cm_info->private_data; + /* Only connect_request and reply have valid private data + * the rest of the events this may be left overs from + * connection establishment. CONNECT_REQUEST is issued via + * qedr_iw_mpa_request + */ + if (event_type == IW_CM_EVENT_CONNECT_REPLY) { + event.private_data_len = + params->cm_info->private_data_len; + event.private_data = + (void *)params->cm_info->private_data; + } } if (ep->cm_id)