Avoid triggering an out-of-bounds stack access by changing the type of 'wr' from ib_send_wr into ib_rdma_wr.

This patch fixes the following KASAN bug report:

BUG: KASAN: stack-out-of-bounds in rxe_post_send+0x7a9/0x9a0 [rdma_rxe] Read of size 8 at addr ffff880068197a48 by task kworker/2:1/44

Workqueue: ib_cm cm_work_handler [ib_cm] Call Trace: dump_stack+0x8e/0xcd print_address_description+0x6f/0x280 kasan_report+0x25a/0x380 __asan_load8+0x54/0x90 rxe_post_send+0x7a9/0x9a0 [rdma_rxe] srpt_zerolength_write+0xf0/0x180 [ib_srpt] srpt_cm_rtu_recv+0x68/0x110 [ib_srpt] srpt_rdma_cm_handler+0xbb/0x15b [ib_srpt] cma_ib_handler+0x1aa/0x4a0 [rdma_cm] cm_process_work+0x30/0x100 [ib_cm] cm_work_handler+0xa86/0x351b [ib_cm] process_one_work+0x475/0x9f0 worker_thread+0x69/0x690 kthread+0x1ad/0x1d0 ret_from_fork+0x3a/0x50

Fixes: aaf45bd83eba ("IB/srpt: Detect session shutdown reliably") Signed-off-by: Bart Van Assche bart.vanassche@wdc.com Cc: Christoph Hellwig hch@lst.de Cc: stable@vger.kernel.org --- drivers/infiniband/ulp/srpt/ib_srpt.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c index 4339ab0607b7..6305da34b5de 100644 --- a/drivers/infiniband/ulp/srpt/ib_srpt.c +++ b/drivers/infiniband/ulp/srpt/ib_srpt.c @@ -848,16 +848,19 @@ static int srpt_post_recv(struct srpt_device *sdev, struct srpt_rdma_ch *ch, */ static int srpt_zerolength_write(struct srpt_rdma_ch *ch) { - struct ib_send_wr wr, *bad_wr; + struct ib_send_wr *bad_wr; + struct ib_rdma_wr wr = { + .wr = { + .opcode = IB_WR_RDMA_WRITE, + .wr_cqe = &ch->zw_cqe, + .send_flags = IB_SEND_SIGNALED, + } + };

pr_debug("%s-%d: queued zerolength write\n", ch->sess_name, ch->qp->qp_num);

- memset(&wr, 0, sizeof(wr)); - wr.opcode = IB_WR_RDMA_WRITE; - wr.wr_cqe = &ch->zw_cqe; - wr.send_flags = IB_SEND_SIGNALED; - return ib_post_send(ch->qp, &wr, &bad_wr); + return ib_post_send(ch->qp, &wr.wr, &bad_wr); }

static void srpt_zerolength_write_done(struct ib_cq *cq, struct ib_wc *wc)