This patch avoids that KASAN reports the following when the SRP initiator calls srp_post_send():

================================================================== BUG: KASAN: stack-out-of-bounds in rxe_post_send+0x5c4/0x980 [rdma_rxe] Read of size 8 at addr ffff880066606e30 by task 02-mq/1074

CPU: 2 PID: 1074 Comm: 02-mq Not tainted 4.16.0-rc3-dbg+ #1 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+0x5c4/0x980 [rdma_rxe] srp_post_send.isra.16+0x149/0x190 [ib_srp] srp_queuecommand+0x94d/0x1670 [ib_srp] scsi_dispatch_cmd+0x1c2/0x550 [scsi_mod] scsi_queue_rq+0x843/0xa70 [scsi_mod] blk_mq_dispatch_rq_list+0x143/0xac0 blk_mq_do_dispatch_ctx+0x1c5/0x260 blk_mq_sched_dispatch_requests+0x2bf/0x2f0 __blk_mq_run_hw_queue+0xdb/0x160 __blk_mq_delay_run_hw_queue+0xba/0x100 blk_mq_run_hw_queue+0xf2/0x190 blk_mq_sched_insert_request+0x163/0x2f0 blk_execute_rq+0xb0/0x130 scsi_execute+0x14e/0x260 [scsi_mod] scsi_probe_and_add_lun+0x366/0x13d0 [scsi_mod] __scsi_scan_target+0x18a/0x810 [scsi_mod] scsi_scan_target+0x11e/0x130 [scsi_mod] srp_create_target+0x1522/0x19e0 [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:ffffea0001998180 count:0 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0x4000000000000000() raw: 4000000000000000 0000000000000000 0000000000000000 00000000ffffffff raw: dead000000000100 dead000000000200 0000000000000000 0000000000000000 page dumped because: kasan: bad access detected

Memory state around the buggy address: ffff880066606d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 ffff880066606d80: f1 00 f2 f2 f2 f2 f2 f2 f2 00 00 f2 f2 f2 f2 f2

ffff880066606e00: f2 00 00 00 00 00 f2 f2 f2 f3 f3 f3 f3 00 00 00

^ ffff880066606e80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff880066606f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================

Fixes: 8700e3e7c485 ("Soft RoCE driver") Signed-off-by: Bart Van Assche bart.vanassche@wdc.com Cc: Moni Shoua monis@mellanox.com Cc: stable@vger.kernel.org --- drivers/infiniband/sw/rxe/rxe_verbs.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/infiniband/sw/rxe/rxe_verbs.c b/drivers/infiniband/sw/rxe/rxe_verbs.c index 3d99965e54fe..753d281b8321 100644 --- a/drivers/infiniband/sw/rxe/rxe_verbs.c +++ b/drivers/infiniband/sw/rxe/rxe_verbs.c @@ -711,9 +711,8 @@ static int init_send_wqe(struct rxe_qp *qp, const struct ib_send_wr *ibwr, memcpy(wqe->dma.sge, ibwr->sg_list, num_sge * sizeof(struct ib_sge));

- wqe->iova = (mask & WR_ATOMIC_MASK) ? - atomic_wr(ibwr)->remote_addr : - rdma_wr(ibwr)->remote_addr; + wqe->iova = mask & WR_ATOMIC_MASK ? atomic_wr(ibwr)->remote_addr : + mask & WR_READ_OR_WRITE_MASK ? rdma_wr(ibwr)->remote_addr : 0; wqe->mask = mask; wqe->dma.length = length; wqe->dma.resid = length;