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Diffstat (limited to 'kernel')
-rw-r--r--kernel/bpf/arraymap.c10
-rw-r--r--kernel/bpf/hashtab.c34
-rw-r--r--kernel/bpf/inode.c6
-rw-r--r--kernel/bpf/syscall.c40
-rw-r--r--kernel/bpf/verifier.c3
5 files changed, 64 insertions, 29 deletions
diff --git a/kernel/bpf/arraymap.c b/kernel/bpf/arraymap.c
index 3f4c99e..b0799bc 100644
--- a/kernel/bpf/arraymap.c
+++ b/kernel/bpf/arraymap.c
@@ -28,11 +28,17 @@ static struct bpf_map *array_map_alloc(union bpf_attr *attr)
attr->value_size == 0)
return ERR_PTR(-EINVAL);
+ if (attr->value_size >= 1 << (KMALLOC_SHIFT_MAX - 1))
+ /* if value_size is bigger, the user space won't be able to
+ * access the elements.
+ */
+ return ERR_PTR(-E2BIG);
+
elem_size = round_up(attr->value_size, 8);
/* check round_up into zero and u32 overflow */
if (elem_size == 0 ||
- attr->max_entries > (U32_MAX - sizeof(*array)) / elem_size)
+ attr->max_entries > (U32_MAX - PAGE_SIZE - sizeof(*array)) / elem_size)
return ERR_PTR(-ENOMEM);
array_size = sizeof(*array) + attr->max_entries * elem_size;
@@ -105,7 +111,7 @@ static int array_map_update_elem(struct bpf_map *map, void *key, void *value,
/* all elements already exist */
return -EEXIST;
- memcpy(array->value + array->elem_size * index, value, array->elem_size);
+ memcpy(array->value + array->elem_size * index, value, map->value_size);
return 0;
}
diff --git a/kernel/bpf/hashtab.c b/kernel/bpf/hashtab.c
index 19909b2..34777b3 100644
--- a/kernel/bpf/hashtab.c
+++ b/kernel/bpf/hashtab.c
@@ -64,12 +64,35 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
*/
goto free_htab;
- err = -ENOMEM;
+ if (htab->map.value_size >= (1 << (KMALLOC_SHIFT_MAX - 1)) -
+ MAX_BPF_STACK - sizeof(struct htab_elem))
+ /* if value_size is bigger, the user space won't be able to
+ * access the elements via bpf syscall. This check also makes
+ * sure that the elem_size doesn't overflow and it's
+ * kmalloc-able later in htab_map_update_elem()
+ */
+ goto free_htab;
+
+ htab->elem_size = sizeof(struct htab_elem) +
+ round_up(htab->map.key_size, 8) +
+ htab->map.value_size;
+
/* prevent zero size kmalloc and check for u32 overflow */
if (htab->n_buckets == 0 ||
htab->n_buckets > U32_MAX / sizeof(struct hlist_head))
goto free_htab;
+ if ((u64) htab->n_buckets * sizeof(struct hlist_head) +
+ (u64) htab->elem_size * htab->map.max_entries >=
+ U32_MAX - PAGE_SIZE)
+ /* make sure page count doesn't overflow */
+ goto free_htab;
+
+ htab->map.pages = round_up(htab->n_buckets * sizeof(struct hlist_head) +
+ htab->elem_size * htab->map.max_entries,
+ PAGE_SIZE) >> PAGE_SHIFT;
+
+ err = -ENOMEM;
htab->buckets = kmalloc_array(htab->n_buckets, sizeof(struct hlist_head),
GFP_USER | __GFP_NOWARN);
@@ -85,13 +108,6 @@ static struct bpf_map *htab_map_alloc(union bpf_attr *attr)
raw_spin_lock_init(&htab->lock);
htab->count = 0;
- htab->elem_size = sizeof(struct htab_elem) +
- round_up(htab->map.key_size, 8) +
- htab->map.value_size;
-
- htab->map.pages = round_up(htab->n_buckets * sizeof(struct hlist_head) +
- htab->elem_size * htab->map.max_entries,
- PAGE_SIZE) >> PAGE_SHIFT;
return &htab->map;
free_htab:
@@ -222,7 +238,7 @@ static int htab_map_update_elem(struct bpf_map *map, void *key, void *value,
WARN_ON_ONCE(!rcu_read_lock_held());
/* allocate new element outside of lock */
- l_new = kmalloc(htab->elem_size, GFP_ATOMIC);
+ l_new = kmalloc(htab->elem_size, GFP_ATOMIC | __GFP_NOWARN);
if (!l_new)
return -ENOMEM;
diff --git a/kernel/bpf/inode.c b/kernel/bpf/inode.c
index be6d726..5a8a797 100644
--- a/kernel/bpf/inode.c
+++ b/kernel/bpf/inode.c
@@ -34,7 +34,7 @@ static void *bpf_any_get(void *raw, enum bpf_type type)
atomic_inc(&((struct bpf_prog *)raw)->aux->refcnt);
break;
case BPF_TYPE_MAP:
- atomic_inc(&((struct bpf_map *)raw)->refcnt);
+ bpf_map_inc(raw, true);
break;
default:
WARN_ON_ONCE(1);
@@ -51,7 +51,7 @@ static void bpf_any_put(void *raw, enum bpf_type type)
bpf_prog_put(raw);
break;
case BPF_TYPE_MAP:
- bpf_map_put(raw);
+ bpf_map_put_with_uref(raw);
break;
default:
WARN_ON_ONCE(1);
@@ -64,7 +64,7 @@ static void *bpf_fd_probe_obj(u32 ufd, enum bpf_type *type)
void *raw;
*type = BPF_TYPE_MAP;
- raw = bpf_map_get(ufd);
+ raw = bpf_map_get_with_uref(ufd);
if (IS_ERR(raw)) {
*type = BPF_TYPE_PROG;
raw = bpf_prog_get(ufd);
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 0d3313d..3b39550 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -82,6 +82,14 @@ static void bpf_map_free_deferred(struct work_struct *work)
map->ops->map_free(map);
}
+static void bpf_map_put_uref(struct bpf_map *map)
+{
+ if (atomic_dec_and_test(&map->usercnt)) {
+ if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY)
+ bpf_fd_array_map_clear(map);
+ }
+}
+
/* decrement map refcnt and schedule it for freeing via workqueue
* (unrelying map implementation ops->map_free() might sleep)
*/
@@ -93,17 +101,15 @@ void bpf_map_put(struct bpf_map *map)
}
}
-static int bpf_map_release(struct inode *inode, struct file *filp)
+void bpf_map_put_with_uref(struct bpf_map *map)
{
- struct bpf_map *map = filp->private_data;
-
- if (map->map_type == BPF_MAP_TYPE_PROG_ARRAY)
- /* prog_array stores refcnt-ed bpf_prog pointers
- * release them all when user space closes prog_array_fd
- */
- bpf_fd_array_map_clear(map);
-
+ bpf_map_put_uref(map);
bpf_map_put(map);
+}
+
+static int bpf_map_release(struct inode *inode, struct file *filp)
+{
+ bpf_map_put_with_uref(filp->private_data);
return 0;
}
@@ -142,6 +148,7 @@ static int map_create(union bpf_attr *attr)
return PTR_ERR(map);
atomic_set(&map->refcnt, 1);
+ atomic_set(&map->usercnt, 1);
err = bpf_map_charge_memlock(map);
if (err)
@@ -174,7 +181,14 @@ struct bpf_map *__bpf_map_get(struct fd f)
return f.file->private_data;
}
-struct bpf_map *bpf_map_get(u32 ufd)
+void bpf_map_inc(struct bpf_map *map, bool uref)
+{
+ atomic_inc(&map->refcnt);
+ if (uref)
+ atomic_inc(&map->usercnt);
+}
+
+struct bpf_map *bpf_map_get_with_uref(u32 ufd)
{
struct fd f = fdget(ufd);
struct bpf_map *map;
@@ -183,7 +197,7 @@ struct bpf_map *bpf_map_get(u32 ufd)
if (IS_ERR(map))
return map;
- atomic_inc(&map->refcnt);
+ bpf_map_inc(map, true);
fdput(f);
return map;
@@ -226,7 +240,7 @@ static int map_lookup_elem(union bpf_attr *attr)
goto free_key;
err = -ENOMEM;
- value = kmalloc(map->value_size, GFP_USER);
+ value = kmalloc(map->value_size, GFP_USER | __GFP_NOWARN);
if (!value)
goto free_key;
@@ -285,7 +299,7 @@ static int map_update_elem(union bpf_attr *attr)
goto free_key;
err = -ENOMEM;
- value = kmalloc(map->value_size, GFP_USER);
+ value = kmalloc(map->value_size, GFP_USER | __GFP_NOWARN);
if (!value)
goto free_key;
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index c607305..a7945d1 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -2021,8 +2021,7 @@ static int replace_map_fd_with_map_ptr(struct verifier_env *env)
* will be used by the valid program until it's unloaded
* and all maps are released in free_bpf_prog_info()
*/
- atomic_inc(&map->refcnt);
-
+ bpf_map_inc(map, false);
fdput(f);
next_insn:
insn++;
generated by cgit v0.10.2 at 2024-10-30 21:11:06 (GMT)