[PATCH 5.6 080/194] bpf: Fix error return code in map_lookup_and_delete_elem()

Greg Kroah-Hartman
2020-05-18T18:12:25Z

From: Wei Yongjun <weiyongjun1@huawei.com>

[ Upstream commit 7f645462ca01d01abb94d75e6768c8b3ed3a188b ]

Fix to return negative error code -EFAULT from the copy_to_user() error
handling case instead of 0, as done elsewhere in this function.

Fixes: bd513cd08f10 ("bpf: add MAP_LOOKUP_AND_DELETE_ELEM syscall")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200430081851.166996-1-weiyongjun1@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/bpf/syscall.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 3b92aea18ae75..e04ea4c8f9358 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1480,8 +1480,10 @@ static int map_lookup_and_delete_elem(union bpf_attr *attr)
if (err)
goto free_value;

- if (copy_to_user(uvalue, value, value_size) != 0)
+ if (copy_to_user(uvalue, value, value_size) != 0) {
+ err = -EFAULT;
goto free_value;
+ }

err = 0;

--
2.20.1