From: Parav Pandit <parav@xxxxxxxxxxxx>
rdma_counter_init() may fail for a device. In such case while calculating
total sum, ignore NULL hstats.
This fixes below observed call trace.
BUG: kernel NULL pointer dereference, address: 00000000000000a0
PGD 8000001009b30067 P4D 8000001009b30067 PUD 10549c9067 PMD 0
Oops: 0000 [#1] SMP PTI
CPU: 55 PID: 20887 Comm: cat Kdump: loaded Not tainted 5.2.0-rc6-jdc+ #13
RIP: 0010:rdma_counter_get_hwstat_value+0xf2/0x150 [ib_core]
Call Trace:
show_hw_stats+0x5e/0x130 [ib_core]
dev_attr_show+0x15/0x50
sysfs_kf_seq_show+0xc6/0x1a0
seq_read+0x132/0x370
vfs_read+0x89/0x140
ksys_read+0x5c/0xd0
do_syscall_64+0x5a/0x240
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Fixes: f34a55e497e81 ("RDMA/core: Get sum value of all counters when perform a sysfs stat read")
Signed-off-by: Parav Pandit <parav@xxxxxxxxxxxx>
Reviewed-by: Mark Zhang <markz@xxxxxxxxxxxx>
Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxxxx>
---
drivers/infiniband/core/counters.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/infiniband/core/counters.c b/drivers/infiniband/core/counters.c
index 01faef7bc061..c7d445635476 100644
--- a/drivers/infiniband/core/counters.c
+++ b/drivers/infiniband/core/counters.c
@@ -393,6 +393,9 @@ u64 rdma_counter_get_hwstat_value(struct ib_device *dev, u8 port, u32 index)
u64 sum;
port_counter = &dev->port_data[port].port_counter;
+ if (!port_counter->hstats)
+ return 0;
+
sum = get_running_counters_hwstat_sum(dev, port, index);
sum += port_counter->hstats->value[index];
--
2.20.1
