Commit 2e3a94aa authored by Brian Vazquez's avatar Brian Vazquez Committed by Daniel Borkmann
Browse files

bpf: Fix memory leaks in generic update/delete batch ops 



Generic update/delete batch ops functions were using __bpf_copy_key
without properly freeing the memory. Handle the memory allocation and
copy_from_user separately.

Fixes: aa2e93b8 ("bpf: Add generic support for update and delete batch ops")
Reported-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: default avatarBrian Vazquez <brianvv@google.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Acked-by: default avatarYonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20200119194040.128369-1-brianvv@google.com
parent a6ed02ca

kernel/bpf/syscall.c

+19 −11
Original line number Diff line number Diff line
@@ -1239,12 +1239,15 @@ int generic_map_delete_batch(struct bpf_map *map, 
	if (!max_count)

		return 0;



	key = kmalloc(map->key_size, GFP_USER | __GFP_NOWARN);

	if (!key)

		return -ENOMEM;



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

		key = __bpf_copy_key(keys + cp * map->key_size, map->key_size);

		if (IS_ERR(key)) {

			err = PTR_ERR(key);

		err = -EFAULT;

		if (copy_from_user(key, keys + cp * map->key_size,

				   map->key_size))

			break;

		}



		if (bpf_map_is_dev_bound(map)) {

			err = bpf_map_offload_delete_elem(map, key);
@@ -1264,6 +1267,8 @@ int generic_map_delete_batch(struct bpf_map *map, 
	}

	if (copy_to_user(&uattr->batch.count, &cp, sizeof(cp)))

		err = -EFAULT;



	kfree(key);

	return err;

}
@@ -1294,18 +1299,21 @@ int generic_map_update_batch(struct bpf_map *map, 
	if (!max_count)

		return 0;



	key = kmalloc(map->key_size, GFP_USER | __GFP_NOWARN);

	if (!key)

		return -ENOMEM;



	value = kmalloc(value_size, GFP_USER | __GFP_NOWARN);

	if (!value)

	if (!value) {

		kfree(key);

		return -ENOMEM;

	}



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

		key = __bpf_copy_key(keys + cp * map->key_size, map->key_size);

		if (IS_ERR(key)) {

			err = PTR_ERR(key);

			break;

		}

		err = -EFAULT;

		if (copy_from_user(value, values + cp * value_size, value_size))

		if (copy_from_user(key, keys + cp * map->key_size,

		    map->key_size) ||

		    copy_from_user(value, values + cp * value_size, value_size))

			break;



		err = bpf_map_update_value(map, f, key, value,

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