[PATCH 5.10 232/406] IB/uverbs: Fix an potential error pointer dereference

Greg Kroah-Hartman
2023-09-17T19:33:47Z

From: Xiang Yang <xiangyang3@huawei.com>

[ Upstream commit 26b7d1a27167e7adf75b150755e05d2bc123ce55 ]

smatch reports the warning below:
drivers/infiniband/core/uverbs_std_types_counters.c:110
ib_uverbs_handler_UVERBS_METHOD_COUNTERS_READ() error: 'uattr'
dereferencing possible ERR_PTR()

The return value of uattr maybe ERR_PTR(-ENOENT), fix this by checking
the value of uattr before using it.

Fixes: ebb6796bd397 ("IB/uverbs: Add read counters support")
Signed-off-by: Xiang Yang <xiangyang3@huawei.com>
Link: https://lore.kernel.org/r/20230804022525.1916766-1-xiangyang3@huawei.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/infiniband/core/uverbs_std_types_counters.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/infiniband/core/uverbs_std_types_counters.c b/drivers/infiniband/core/uverbs_std_types_counters.c
index b3c6c066b6010..c61b10fbf90a9 100644
--- a/drivers/infiniband/core/uverbs_std_types_counters.c
+++ b/drivers/infiniband/core/uverbs_std_types_counters.c
@@ -108,6 +108,8 @@ static int UVERBS_HANDLER(UVERBS_METHOD_COUNTERS_READ)(
return ret;

uattr = uverbs_attr_get(attrs, UVERBS_ATTR_READ_COUNTERS_BUFF);
+ if (IS_ERR(uattr))
+ return PTR_ERR(uattr);
read_attr.ncounters = uattr->ptr_attr.len / sizeof(u64);
read_attr.counters_buff = uverbs_zalloc(
attrs, array_size(read_attr.ncounters, sizeof(u64)));
--
2.40.1