This patch fixes the following KASAN complaint:

================================================================== BUG: KASAN: stack-out-of-bounds in rxe_post_send+0x77d/0x9b0 [rdma_rxe] Read of size 8 at addr ffff880061aef860 by task 01/1080

CPU: 2 PID: 1080 Comm: 01 Not tainted 4.16.0-rc3-dbg+ #2 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/01/2014 Call Trace: dump_stack+0x85/0xc7 print_address_description+0x65/0x270 kasan_report+0x231/0x350 rxe_post_send+0x77d/0x9b0 [rdma_rxe] __ib_drain_sq+0x1ad/0x250 [ib_core] ib_drain_qp+0x9/0x30 [ib_core] srp_destroy_qp+0x51/0x70 [ib_srp] srp_free_ch_ib+0xfc/0x380 [ib_srp] srp_create_target+0x1071/0x19e0 [ib_srp] kernfs_fop_write+0x180/0x210 __vfs_write+0xb1/0x2e0 vfs_write+0xf6/0x250 SyS_write+0x99/0x110 do_syscall_64+0xee/0x2b0 entry_SYSCALL_64_after_hwframe+0x42/0xb7

The buggy address belongs to the page: page:ffffea000186bbc0 count:0 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0x4000000000000000() raw: 4000000000000000 0000000000000000 0000000000000000 00000000ffffffff raw: 0000000000000000 ffffea000186bbe0 0000000000000000 0000000000000000 page dumped because: kasan: bad access detected

Memory state around the buggy address: ffff880061aef700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff880061aef780: 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00

ffff880061aef800: f2 f2 f2 f2 f2 f2 f2 00 00 00 00 00 f2 f2 f2 f2

^ ffff880061aef880: f2 f2 f2 00 00 00 00 00 00 00 00 00 00 00 f2 f2 ffff880061aef900: f2 f2 f2 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================

Fixes: 765d67748bcf ("IB: new common API for draining queues") Signed-off-by: Bart Van Assche bart.vanassche@wdc.com Cc: Steve Wise swise@opengridcomputing.com Cc: Sagi Grimberg sagi@grimberg.me Cc: stable@vger.kernel.org --- drivers/infiniband/core/verbs.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/infiniband/core/verbs.c b/drivers/infiniband/core/verbs.c index 2c7b0ceb46e6..4e2b231b03f7 100644 --- a/drivers/infiniband/core/verbs.c +++ b/drivers/infiniband/core/verbs.c @@ -2194,7 +2194,13 @@ static void __ib_drain_sq(struct ib_qp *qp) struct ib_cq *cq = qp->send_cq; struct ib_qp_attr attr = { .qp_state = IB_QPS_ERR }; struct ib_drain_cqe sdrain; - struct ib_send_wr swr = {}, *bad_swr; + struct ib_send_wr *bad_swr; + struct ib_rdma_wr swr = { + .wr = { + .opcode = IB_WR_RDMA_WRITE, + .wr_cqe = &sdrain.cqe, + }, + }; int ret;

ret = ib_modify_qp(qp, &attr, IB_QP_STATE); @@ -2203,11 +2209,10 @@ static void __ib_drain_sq(struct ib_qp *qp) return; }

- swr.wr_cqe = &sdrain.cqe; sdrain.cqe.done = ib_drain_qp_done; init_completion(&sdrain.done);

- ret = ib_post_send(qp, &swr, &bad_swr); + ret = ib_post_send(qp, &swr.wr, &bad_swr); if (ret) { WARN_ONCE(ret, "failed to drain send queue: %d\n", ret); return;