[PATCH v2 for-rc 5/8] RDMA/hns: Fix shift-out-bounds when max_inline_data is 0

[Junxian Huang]

From: Chengchang Tang <tangchengchang@xxxxxxxxxx>

A shift-out-bounds may occur, if the max_inline_data has not been set.

The related log:
UBSAN: shift-out-of-bounds in kernel/include/linux/log2.h:57:13
shift exponent 64 is too large for 64-bit type 'long unsigned int'
Call trace:
 dump_backtrace+0xb0/0x118
 show_stack+0x20/0x38
 dump_stack_lvl+0xbc/0x120
 dump_stack+0x1c/0x28
 __ubsan_handle_shift_out_of_bounds+0x104/0x240
 set_ext_sge_param+0x40c/0x420 [hns_roce_hw_v2]
 hns_roce_create_qp+0xf48/0x1c40 [hns_roce_hw_v2]
 create_qp.part.0+0x294/0x3c0
 ib_create_qp_kernel+0x7c/0x150
 create_mad_qp+0x11c/0x1e0
 ib_mad_init_device+0x834/0xc88
 add_client_context+0x248/0x318
 enable_device_and_get+0x158/0x280
 ib_register_device+0x4ac/0x610
 hns_roce_init+0x890/0xf98 [hns_roce_hw_v2]
 __hns_roce_hw_v2_init_instance+0x398/0x720 [hns_roce_hw_v2]
 hns_roce_hw_v2_init_instance+0x108/0x1e0 [hns_roce_hw_v2]
 hclge_init_roce_client_instance+0x1a0/0x358 [hclge]
 hclge_init_client_instance+0xa0/0x508 [hclge]
 hnae3_register_client+0x18c/0x210 [hnae3]
 hns_roce_hw_v2_init+0x28/0xff8 [hns_roce_hw_v2]
 do_one_initcall+0xe0/0x510
 do_init_module+0x110/0x370
 load_module+0x2c6c/0x2f20
 init_module_from_file+0xe0/0x140
 idempotent_init_module+0x24c/0x350
 __arm64_sys_finit_module+0x88/0xf8
 invoke_syscall+0x68/0x1a0
 el0_svc_common.constprop.0+0x11c/0x150
 do_el0_svc+0x38/0x50
 el0_svc+0x50/0xa0
 el0t_64_sync_handler+0xc0/0xc8
 el0t_64_sync+0x1a4/0x1a8

Fixes: 0c5e259b06a8 ("RDMA/hns: Fix incorrect sge nums calculation")
Signed-off-by: Chengchang Tang <tangchengchang@xxxxxxxxxx>
Signed-off-by: Junxian Huang <huangjunxian6@xxxxxxxxxxxxx>
---
 drivers/infiniband/hw/hns/hns_roce_qp.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/infiniband/hw/hns/hns_roce_qp.c b/drivers/infiniband/hw/hns/hns_roce_qp.c
index db34665d1dfb..1de384ce4d0e 100644
--- a/drivers/infiniband/hw/hns/hns_roce_qp.c
+++ b/drivers/infiniband/hw/hns/hns_roce_qp.c
@@ -532,13 +532,15 @@ static unsigned int get_sge_num_from_max_inl_data(bool is_ud_or_gsi,
 {
 	unsigned int inline_sge;
 
-	inline_sge = roundup_pow_of_two(max_inline_data) / HNS_ROCE_SGE_SIZE;
+	if (!max_inline_data)
+		return 0;
 
 	/*
 	 * if max_inline_data less than
 	 * HNS_ROCE_SGE_IN_WQE * HNS_ROCE_SGE_SIZE,
 	 * In addition to ud's mode, no need to extend sge.
 	 */
+	inline_sge = roundup_pow_of_two(max_inline_data) / HNS_ROCE_SGE_SIZE;
 	if (!is_ud_or_gsi && inline_sge <= HNS_ROCE_SGE_IN_WQE)
 		inline_sge = 0;
 
-- 
2.33.0