From a379d1ce32f1c97b19d68cffbd195e025dbb9d43 Mon Sep 17 00:00:00 2001 From: Parav Pandit Date: Tue, 23 Jul 2019 09:57:32 +0300 Subject: IB/core: Fix querying total rdma stats 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: f34a55e497e8 ("RDMA/core: Get sum value of all counters when perform a sysfs stat read") Link: https://lore.kernel.org/r/20190723065733.4899-10-leon@kernel.org Signed-off-by: Parav Pandit Reviewed-by: Mark Zhang Signed-off-by: Leon Romanovsky Signed-off-by: Jason Gunthorpe --- drivers/infiniband/core/counters.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers') 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]; -- cgit v1.2.3-59-g8ed1b