From: Sergey Gorenko sergeygo@mellanox.com
commit 0fbb37dd82998b5c83355997b3bdba2806968ac7 upstream.
Some SRP targets that do not support specification SRP-2, put the garbage to the reserved bits of the SRP login response. The problem was not detected for a long time because the SRP initiator ignored those bits. But now one of them is used as SRP_LOGIN_RSP_IMMED_SUPP. And it causes a critical error on the target when the initiator sends immediate data.
The ib_srp module has a use_imm_date parameter to enable or disable immediate data manually. But it does not help in the above case, because use_imm_date is ignored at handling the SRP login response. The problem is definitely caused by a bug on the target side, but the initiator's behavior also does not look correct. The initiator should not use immediate data if use_imm_date is disabled by a user.
This commit adds an additional checking of use_imm_date at the handling of SRP login response to avoid unexpected use of immediate data.
Fixes: 882981f4a411 ("RDMA/srp: Add support for immediate data") Link: https://lore.kernel.org/r/20200115133055.30232-1-sergeygo@mellanox.com Signed-off-by: Sergey Gorenko sergeygo@mellanox.com Reviewed-by: Bart Van Assche bvanassche@acm.org Signed-off-by: Jason Gunthorpe jgg@mellanox.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/infiniband/ulp/srp/ib_srp.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/infiniband/ulp/srp/ib_srp.c +++ b/drivers/infiniband/ulp/srp/ib_srp.c @@ -2546,7 +2546,8 @@ static void srp_cm_rep_handler(struct ib if (lrsp->opcode == SRP_LOGIN_RSP) { ch->max_ti_iu_len = be32_to_cpu(lrsp->max_ti_iu_len); ch->req_lim = be32_to_cpu(lrsp->req_lim_delta); - ch->use_imm_data = lrsp->rsp_flags & SRP_LOGIN_RSP_IMMED_SUPP; + ch->use_imm_data = srp_use_imm_data && + (lrsp->rsp_flags & SRP_LOGIN_RSP_IMMED_SUPP); ch->max_it_iu_len = srp_max_it_iu_len(target->cmd_sg_cnt, ch->use_imm_data, target->max_it_iu_size);