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Diffstat (limited to 'kernel/bpf/arraymap.c')
-rw-r--r--kernel/bpf/arraymap.c46
1 files changed, 28 insertions, 18 deletions
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
index fe40d3b9458f..624527401d4d 100644
--- a/kernel/bpf/arraymap.c
+++ b/kernel/bpf/arraymap.c
@@ -70,10 +70,8 @@ int array_map_alloc_check(union bpf_attr *attr)
attr->map_flags & BPF_F_PRESERVE_ELEMS)
return -EINVAL;
- if (attr->value_size > KMALLOC_MAX_SIZE)
- /* if value_size is bigger, the user space won't be able to
- * access the elements.
- */
+ /* avoid overflow on round_up(map->value_size) */
+ if (attr->value_size > INT_MAX)
return -E2BIG;
return 0;
@@ -156,6 +154,11 @@ static struct bpf_map *array_map_alloc(union bpf_attr *attr)
return &array->map;
}
+static void *array_map_elem_ptr(struct bpf_array* array, u32 index)
+{
+ return array->value + (u64)array->elem_size * index;
+}
+
/* Called from syscall or from eBPF program */
static void *array_map_lookup_elem(struct bpf_map *map, void *key)
{
@@ -165,7 +168,7 @@ static void *array_map_lookup_elem(struct bpf_map *map, void *key)
if (unlikely(index >= array->map.max_entries))
return NULL;
- return array->value + array->elem_size * (index & array->index_mask);
+ return array->value + (u64)array->elem_size * (index & array->index_mask);
}
static int array_map_direct_value_addr(const struct bpf_map *map, u64 *imm,
@@ -203,7 +206,7 @@ static int array_map_gen_lookup(struct bpf_map *map, struct bpf_insn *insn_buf)
{
struct bpf_array *array = container_of(map, struct bpf_array, map);
struct bpf_insn *insn = insn_buf;
- u32 elem_size = round_up(map->value_size, 8);
+ u32 elem_size = array->elem_size;
const int ret = BPF_REG_0;
const int map_ptr = BPF_REG_1;
const int index = BPF_REG_2;
@@ -272,7 +275,7 @@ int bpf_percpu_array_copy(struct bpf_map *map, void *key, void *value)
* access 'value_size' of them, so copying rounded areas
* will not leak any kernel data
*/
- size = round_up(map->value_size, 8);
+ size = array->elem_size;
rcu_read_lock();
pptr = array->pptrs[index & array->index_mask];
for_each_possible_cpu(cpu) {
@@ -339,7 +342,7 @@ static int array_map_update_elem(struct bpf_map *map, void *key, void *value,
value, map->value_size);
} else {
val = array->value +
- array->elem_size * (index & array->index_mask);
+ (u64)array->elem_size * (index & array->index_mask);
if (map_flags & BPF_F_LOCK)
copy_map_value_locked(map, val, value, false);
else
@@ -376,7 +379,7 @@ int bpf_percpu_array_update(struct bpf_map *map, void *key, void *value,
* returned or zeros which were zero-filled by percpu_alloc,
* so no kernel data leaks possible
*/
- size = round_up(map->value_size, 8);
+ size = array->elem_size;
rcu_read_lock();
pptr = array->pptrs[index & array->index_mask];
for_each_possible_cpu(cpu) {
@@ -408,8 +411,7 @@ static void array_map_free_timers(struct bpf_map *map)
return;
for (i = 0; i < array->map.max_entries; i++)
- bpf_timer_cancel_and_free(array->value + array->elem_size * i +
- map->timer_off);
+ bpf_timer_cancel_and_free(array_map_elem_ptr(array, i) + map->timer_off);
}
/* Called when map->refcnt goes to zero, either from workqueue or from syscall */
@@ -420,7 +422,7 @@ static void array_map_free(struct bpf_map *map)
if (map_value_has_kptrs(map)) {
for (i = 0; i < array->map.max_entries; i++)
- bpf_map_free_kptrs(map, array->value + array->elem_size * i);
+ bpf_map_free_kptrs(map, array_map_elem_ptr(array, i));
bpf_map_free_kptr_off_tab(map);
}
@@ -556,7 +558,7 @@ static void *bpf_array_map_seq_start(struct seq_file *seq, loff_t *pos)
index = info->index & array->index_mask;
if (info->percpu_value_buf)
return array->pptrs[index];
- return array->value + array->elem_size * index;
+ return array_map_elem_ptr(array, index);
}
static void *bpf_array_map_seq_next(struct seq_file *seq, void *v, loff_t *pos)
@@ -575,7 +577,7 @@ static void *bpf_array_map_seq_next(struct seq_file *seq, void *v, loff_t *pos)
index = info->index & array->index_mask;
if (info->percpu_value_buf)
return array->pptrs[index];
- return array->value + array->elem_size * index;
+ return array_map_elem_ptr(array, index);
}
static int __bpf_array_map_seq_show(struct seq_file *seq, void *v)
@@ -583,6 +585,7 @@ static int __bpf_array_map_seq_show(struct seq_file *seq, void *v)
struct bpf_iter_seq_array_map_info *info = seq->private;
struct bpf_iter__bpf_map_elem ctx = {};
struct bpf_map *map = info->map;
+ struct bpf_array *array = container_of(map, struct bpf_array, map);
struct bpf_iter_meta meta;
struct bpf_prog *prog;
int off = 0, cpu = 0;
@@ -603,7 +606,7 @@ static int __bpf_array_map_seq_show(struct seq_file *seq, void *v)
ctx.value = v;
} else {
pptr = v;
- size = round_up(map->value_size, 8);
+ size = array->elem_size;
for_each_possible_cpu(cpu) {
bpf_long_memcpy(info->percpu_value_buf + off,
per_cpu_ptr(pptr, cpu),
@@ -633,11 +636,12 @@ static int bpf_iter_init_array_map(void *priv_data,
{
struct bpf_iter_seq_array_map_info *seq_info = priv_data;
struct bpf_map *map = aux->map;
+ struct bpf_array *array = container_of(map, struct bpf_array, map);
void *value_buf;
u32 buf_size;
if (map->map_type == BPF_MAP_TYPE_PERCPU_ARRAY) {
- buf_size = round_up(map->value_size, 8) * num_possible_cpus();
+ buf_size = array->elem_size * num_possible_cpus();
value_buf = kmalloc(buf_size, GFP_USER | __GFP_NOWARN);
if (!value_buf)
return -ENOMEM;
@@ -645,6 +649,11 @@ static int bpf_iter_init_array_map(void *priv_data,
seq_info->percpu_value_buf = value_buf;
}
+ /* bpf_iter_attach_map() acquires a map uref, and the uref may be
+ * released before or in the middle of iterating map elements, so
+ * acquire an extra map uref for iterator.
+ */
+ bpf_map_inc_with_uref(map);
seq_info->map = map;
return 0;
}
@@ -653,6 +662,7 @@ static void bpf_iter_fini_array_map(void *priv_data)
{
struct bpf_iter_seq_array_map_info *seq_info = priv_data;
+ bpf_map_put_with_uref(seq_info->map);
kfree(seq_info->percpu_value_buf);
}
@@ -690,7 +700,7 @@ static int bpf_for_each_array_elem(struct bpf_map *map, bpf_callback_t callback_
if (is_percpu)
val = this_cpu_ptr(array->pptrs[i]);
else
- val = array->value + array->elem_size * i;
+ val = array_map_elem_ptr(array, i);
num_elems++;
key = i;
ret = callback_fn((u64)(long)map, (u64)(long)&key,
@@ -1322,7 +1332,7 @@ static int array_of_map_gen_lookup(struct bpf_map *map,
struct bpf_insn *insn_buf)
{
struct bpf_array *array = container_of(map, struct bpf_array, map);
- u32 elem_size = round_up(map->value_size, 8);
+ u32 elem_size = array->elem_size;
struct bpf_insn *insn = insn_buf;
const int ret = BPF_REG_0;
const int map_ptr = BPF_REG_1;
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