bpf: Set uattr->batch.count as zero before batched update or deletion

generic_map_{delete,update}_batch() doesn't set uattr->batch.count as
zero before it tries to allocate memory for key. If the memory
allocation fails, the value of uattr->batch.count will be incorrect.

Fix it by setting uattr->batch.count as zero beore batched update or
deletion.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20231208102355.2628918-6-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Hou Tao 2023-12-08 18:23:53 +08:00 committed by Alexei Starovoitov
parent 67ad2c73ff
commit 06e5c999f1

View file

@ -1731,6 +1731,9 @@ int generic_map_delete_batch(struct bpf_map *map,
if (!max_count)
return 0;
if (put_user(0, &uattr->batch.count))
return -EFAULT;
key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
if (!key)
return -ENOMEM;
@ -1787,6 +1790,9 @@ int generic_map_update_batch(struct bpf_map *map, struct file *map_file,
if (!max_count)
return 0;
if (put_user(0, &uattr->batch.count))
return -EFAULT;
key = kvmalloc(map->key_size, GFP_USER | __GFP_NOWARN);
if (!key)
return -ENOMEM;