[PATCH AUTOSEL 5.6 051/149] RDMA/rxe: Fix configuration of atomic queue pair attributes

Sasha Levin
2020-04-11T23:04:59Z

From: Bart Van Assche <bvanassche@acm.org>

[ Upstream commit fb3063d31995cc4cf1d47a406bb61d6fb1b1d58d ]

From the comment above the definition of the roundup_pow_of_two() macro:

The result is undefined when n == 0.

Hence only pass positive values to roundup_pow_of_two(). This patch fixes
the following UBSAN complaint:

UBSAN: Undefined behaviour in ./include/linux/log2.h:57:13
shift exponent 64 is too large for 64-bit type 'long unsigned int'
Call Trace:
dump_stack+0xa5/0xe6
ubsan_epilogue+0x9/0x26
__ubsan_handle_shift_out_of_bounds.cold+0x4c/0xf9
rxe_qp_from_attr.cold+0x37/0x5d [rdma_rxe]
rxe_modify_qp+0x59/0x70 [rdma_rxe]
_ib_modify_qp+0x5aa/0x7c0 [ib_core]
ib_modify_qp+0x3b/0x50 [ib_core]
cma_modify_qp_rtr+0x234/0x260 [rdma_cm]
__rdma_accept+0x1a7/0x650 [rdma_cm]
nvmet_rdma_cm_handler+0x1286/0x14cd [nvmet_rdma]
cma_cm_event_handler+0x6b/0x330 [rdma_cm]
cma_ib_req_handler+0xe60/0x22d0 [rdma_cm]
cm_process_work+0x30/0x140 [ib_cm]
cm_req_handler+0x11f4/0x1cd0 [ib_cm]
cm_work_handler+0xb8/0x344e [ib_cm]
process_one_work+0x569/0xb60
worker_thread+0x7a/0x5d0
kthread+0x1e6/0x210
ret_from_fork+0x24/0x30

Link: https://lore.kernel.org/r/20200217205714.26937-1-bvanassche@acm.org
Fixes: 8700e3e7c485 ("Soft RoCE driver")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/infiniband/sw/rxe/rxe_qp.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/infiniband/sw/rxe/rxe_qp.c b/drivers/infiniband/sw/rxe/rxe_qp.c
index ec21f616ac98d..6c11c3aeeca6e 100644
--- a/drivers/infiniband/sw/rxe/rxe_qp.c
+++ b/drivers/infiniband/sw/rxe/rxe_qp.c
@@ -590,15 +590,16 @@ int rxe_qp_from_attr(struct rxe_qp *qp, struct ib_qp_attr *attr, int mask,
int err;

if (mask & IB_QP_MAX_QP_RD_ATOMIC) {
- int max_rd_atomic = __roundup_pow_of_two(attr->max_rd_atomic);
+ int max_rd_atomic = attr->max_rd_atomic ?
+ roundup_pow_of_two(attr->max_rd_atomic) : 0;

qp->attr.max_rd_atomic = max_rd_atomic;
atomic_set(&qp->req.rd_atomic, max_rd_atomic);
}

if (mask & IB_QP_MAX_DEST_RD_ATOMIC) {
- int max_dest_rd_atomic =
- __roundup_pow_of_two(attr->max_dest_rd_atomic);
+ int max_dest_rd_atomic = attr->max_dest_rd_atomic ?
+ roundup_pow_of_two(attr->max_dest_rd_atomic) : 0;

qp->attr.max_dest_rd_atomic = max_dest_rd_atomic;

--
2.20.1