Commit fda7a387 authored by Xu Kuohai's avatar Xu Kuohai Committed by Alexei Starovoitov
Browse files

bpf: Fix error usage of map_fd and fdget() in generic_map_update_batch() 



1. The ufd in generic_map_update_batch() should be read from batch.map_fd;
2. A call to fdget() should be followed by a symmetric call to fdput().

Fixes: aa2e93b8 ("bpf: Add generic support for update and delete batch ops")
Signed-off-by: default avatarXu Kuohai <xukuohai@huawei.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20211019032934.1210517-1-xukuohai@huawei.com
parent 22a12790

kernel/bpf/syscall.c

+3 −2
Original line number Diff line number Diff line
@@ -1337,12 +1337,11 @@ int generic_map_update_batch(struct bpf_map *map, 
	void __user *values = u64_to_user_ptr(attr->batch.values);

	void __user *keys = u64_to_user_ptr(attr->batch.keys);

	u32 value_size, cp, max_count;

	int ufd = attr->map_fd;

	int ufd = attr->batch.map_fd;

	void *key, *value;

	struct fd f;

	int err = 0;



	f = fdget(ufd);

	if (attr->batch.elem_flags & ~BPF_F_LOCK)

		return -EINVAL;
@@ -1367,6 +1366,7 @@ int generic_map_update_batch(struct bpf_map *map, 
		return -ENOMEM;

	}



	f = fdget(ufd); /* bpf_map_do_batch() guarantees ufd is valid */

	for (cp = 0; cp < max_count; cp++) {

		err = -EFAULT;

		if (copy_from_user(key, keys + cp * map->key_size,
@@ -1386,6 +1386,7 @@ int generic_map_update_batch(struct bpf_map *map, 


	kvfree(value);

	kvfree(key);

	fdput(f);

	return err;

}