在 2022/9/10 1:27, sdf@xxxxxxxxxx 写道:
On 09/09, Wang Yufen wrote:
Use kvmemdup_bpfptr helper instead of open-coding to
simplify the code.
Signed-off-by: Wang Yufen <wangyufen@xxxxxxxxxx>
---
kernel/bpf/syscall.c | 14 ++++----------
1 file changed, 4 insertions(+), 10 deletions(-)
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 4e9d4622aef7..13ce28081982 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -1413,20 +1413,14 @@ static int map_update_elem(union bpf_attr
*attr, bpfptr_t uattr)
}
value_size = bpf_map_value_size(map);
-
- err = -ENOMEM;
- value = kvmalloc(value_size, GFP_USER | __GFP_NOWARN);
- if (!value)
+ value = kvmemdup_bpfptr(uvalue, value_size);
+ if (IS_ERR(value)) {
+ err = PTR_ERR(value);
goto free_key;
-
- err = -EFAULT;
- if (copy_from_bpfptr(value, uvalue, value_size) != 0)
- goto free_value;
+ }
err = bpf_map_update_value(map, f, key, value, attr->flags);
[..]
-free_value:
- kvfree(value);
And here you leak the value. We need to free it after update regardless
of error/success. That's why it is coded like that.
Thanks for your comments.
It's my mistake.
Can I keep kvfree(value); and send v2?
free_key:
kvfree(key);
err_put:
--
2.25.1
