[PATCH AUTOSEL 4.19 187/191] IB/iser: Fix possible NULL deref at iser_inv_desc()

Sasha Levin
2019-11-10T03:07:15Z

From: Israel Rukshin <israelr@mellanox.com>

[ Upstream commit 65f07f5a09dacf3b60619f196f096ea3671a5eda ]

In case target remote invalidates bogus rkey and signature is not used,
pi_ctx is NULL deref.

The commit also fails the connection on bogus remote invalidation.

Fixes: 59caaed7a72a ("IB/iser: Support the remote invalidation exception")
Signed-off-by: Israel Rukshin <israelr@mellanox.com>
Reviewed-by: Max Gurtovoy <maxg@mellanox.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/infiniband/ulp/iser/iser_initiator.c | 18 +++++++++++++-----
1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/drivers/infiniband/ulp/iser/iser_initiator.c b/drivers/infiniband/ulp/iser/iser_initiator.c
index 2f6388596f886..96af06cfe0afd 100644
--- a/drivers/infiniband/ulp/iser/iser_initiator.c
+++ b/drivers/infiniband/ulp/iser/iser_initiator.c
@@ -589,13 +589,19 @@ void iser_login_rsp(struct ib_cq *cq, struct ib_wc *wc)
ib_conn->post_recv_buf_count--;
}

-static inline void
+static inline int
iser_inv_desc(struct iser_fr_desc *desc, u32 rkey)
{
- if (likely(rkey == desc->rsc.mr->rkey))
+ if (likely(rkey == desc->rsc.mr->rkey)) {
desc->rsc.mr_valid = 0;
- else if (likely(rkey == desc->pi_ctx->sig_mr->rkey))
+ } else if (likely(desc->pi_ctx && rkey == desc->pi_ctx->sig_mr->rkey)) {
desc->pi_ctx->sig_mr_valid = 0;
+ } else {
+ iser_err("Bogus remote invalidation for rkey %#x\n", rkey);
+ return -EINVAL;
+ }
+
+ return 0;
}

static int
@@ -623,12 +629,14 @@ iser_check_remote_inv(struct iser_conn *iser_conn,

if (iser_task->dir[ISER_DIR_IN]) {
desc = iser_task->rdma_reg[ISER_DIR_IN].mem_h;
- iser_inv_desc(desc, rkey);
+ if (unlikely(iser_inv_desc(desc, rkey)))
+ return -EINVAL;
}

if (iser_task->dir[ISER_DIR_OUT]) {
desc = iser_task->rdma_reg[ISER_DIR_OUT].mem_h;
- iser_inv_desc(desc, rkey);
+ if (unlikely(iser_inv_desc(desc, rkey)))
+ return -EINVAL;
}
} else {
iser_err("failed to get task for itt=%d\n", hdr->itt);
--
2.20.1