commit 7f645462ca01d01abb94d75e6768c8b3ed3a188b
author Wei Yongjun <weiyongjun1@huawei.com> Thu Apr 30 08:18:51 2020 +0000
committer Daniel Borkmann <daniel@iogearbox.net> Thu Apr 30 16:19:08 2020 +0200
tree 9b4fe3e64486b14b38c6598a089e5ca6bc5107cb
parent 18f02ad19e2c2a1d9e1d55a4e1c0cbf51419151c

bpf: Fix error return code in map_lookup_and_delete_elem()

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

kernel/bpf/syscall.c

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 7626b802..2843bbb 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1485,8 +1485,10 @@ 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;