[PATCH 4.19 096/106] net/rds: Fix error handling in rds_ib_add_one()

From: Greg Kroah-Hartman
Date: Sun Oct 06 2019 - 13:58:32 EST


From: Dotan Barak <dotanb@xxxxxxxxxxxxxxxxxx>

[ Upstream commit d64bf89a75b65f83f06be9fb8f978e60d53752db ]

rds_ibdev:ipaddr_list and rds_ibdev:conn_list are initialized
after allocation some resources such as protection domain.
If allocation of such resources fail, then these uninitialized
variables are accessed in rds_ib_dev_free() in failure path. This
can potentially crash the system. The code has been updated to
initialize these variables very early in the function.

Signed-off-by: Dotan Barak <dotanb@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Sudhakar Dindukurti <sudhakar.dindukurti@xxxxxxxxxx>
Acked-by: Santosh Shilimkar <santosh.shilimkar@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/rds/ib.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- a/net/rds/ib.c
+++ b/net/rds/ib.c
@@ -143,6 +143,9 @@ static void rds_ib_add_one(struct ib_dev
refcount_set(&rds_ibdev->refcount, 1);
INIT_WORK(&rds_ibdev->free_work, rds_ib_dev_free);

+ INIT_LIST_HEAD(&rds_ibdev->ipaddr_list);
+ INIT_LIST_HEAD(&rds_ibdev->conn_list);
+
rds_ibdev->max_wrs = device->attrs.max_qp_wr;
rds_ibdev->max_sge = min(device->attrs.max_send_sge, RDS_IB_MAX_SGE);

@@ -203,9 +206,6 @@ static void rds_ib_add_one(struct ib_dev
device->name,
rds_ibdev->use_fastreg ? "FRMR" : "FMR");

- INIT_LIST_HEAD(&rds_ibdev->ipaddr_list);
- INIT_LIST_HEAD(&rds_ibdev->conn_list);
-
down_write(&rds_ib_devices_lock);
list_add_tail_rcu(&rds_ibdev->list, &rds_ib_devices);
up_write(&rds_ib_devices_lock);