1 files changed, 150 insertions, 84 deletions

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index f1c8733f76b8..1480b6cf12f0 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -109,37 +109,6 @@ const struct bpf_map_ops bpf_map_offload_ops = {
 	.map_mem_usage = bpf_map_offload_map_mem_usage,
 };
 
-static struct bpf_map *find_and_alloc_map(union bpf_attr *attr)
-{
-	const struct bpf_map_ops *ops;
-	u32 type = attr->map_type;
-	struct bpf_map *map;
-	int err;
-
-	if (type >= ARRAY_SIZE(bpf_map_types))
-		return ERR_PTR(-EINVAL);
-	type = array_index_nospec(type, ARRAY_SIZE(bpf_map_types));
-	ops = bpf_map_types[type];
-	if (!ops)
-		return ERR_PTR(-EINVAL);
-
-	if (ops->map_alloc_check) {
-		err = ops->map_alloc_check(attr);
-		if (err)
-			return ERR_PTR(err);
-	}
-	if (attr->map_ifindex)
-		ops = &bpf_map_offload_ops;
-	if (!ops->map_mem_usage)
-		return ERR_PTR(-EINVAL);
-	map = ops->map_alloc(attr);
-	if (IS_ERR(map))
-		return map;
-	map->ops = ops;
-	map->map_type = type;
-	return map;
-}
-
 static void bpf_map_write_active_inc(struct bpf_map *map)
 {
 	atomic64_inc(&map->writecnt);
@@ -1127,7 +1096,9 @@ free_map_tab:
 /* called via syscall */
 static int map_create(union bpf_attr *attr)
 {
+	const struct bpf_map_ops *ops;
 	int numa_node = bpf_map_attr_numa_node(attr);
+	u32 map_type = attr->map_type;
 	struct bpf_map *map;
 	int f_flags;
 	int err;
@@ -1158,9 +1129,85 @@ static int map_create(union bpf_attr *attr)
 		return -EINVAL;
 
 	/* find map type and init map: hashtable vs rbtree vs bloom vs ... */
-	map = find_and_alloc_map(attr);
+	map_type = attr->map_type;
+	if (map_type >= ARRAY_SIZE(bpf_map_types))
+		return -EINVAL;
+	map_type = array_index_nospec(map_type, ARRAY_SIZE(bpf_map_types));
+	ops = bpf_map_types[map_type];
+	if (!ops)
+		return -EINVAL;
+
+	if (ops->map_alloc_check) {
+		err = ops->map_alloc_check(attr);
+		if (err)
+			return err;
+	}
+	if (attr->map_ifindex)
+		ops = &bpf_map_offload_ops;
+	if (!ops->map_mem_usage)
+		return -EINVAL;
+
+	/* Intent here is for unprivileged_bpf_disabled to block BPF map
+	 * creation for unprivileged users; other actions depend
+	 * on fd availability and access to bpffs, so are dependent on
+	 * object creation success. Even with unprivileged BPF disabled,
+	 * capability checks are still carried out.
+	 */
+	if (sysctl_unprivileged_bpf_disabled && !bpf_capable())
+		return -EPERM;
+
+	/* check privileged map type permissions */
+	switch (map_type) {
+	case BPF_MAP_TYPE_ARRAY:
+	case BPF_MAP_TYPE_PERCPU_ARRAY:
+	case BPF_MAP_TYPE_PROG_ARRAY:
+	case BPF_MAP_TYPE_PERF_EVENT_ARRAY:
+	case BPF_MAP_TYPE_CGROUP_ARRAY:
+	case BPF_MAP_TYPE_ARRAY_OF_MAPS:
+	case BPF_MAP_TYPE_HASH:
+	case BPF_MAP_TYPE_PERCPU_HASH:
+	case BPF_MAP_TYPE_HASH_OF_MAPS:
+	case BPF_MAP_TYPE_RINGBUF:
+	case BPF_MAP_TYPE_USER_RINGBUF:
+	case BPF_MAP_TYPE_CGROUP_STORAGE:
+	case BPF_MAP_TYPE_PERCPU_CGROUP_STORAGE:
+		/* unprivileged */
+		break;
+	case BPF_MAP_TYPE_SK_STORAGE:
+	case BPF_MAP_TYPE_INODE_STORAGE:
+	case BPF_MAP_TYPE_TASK_STORAGE:
+	case BPF_MAP_TYPE_CGRP_STORAGE:
+	case BPF_MAP_TYPE_BLOOM_FILTER:
+	case BPF_MAP_TYPE_LPM_TRIE:
+	case BPF_MAP_TYPE_REUSEPORT_SOCKARRAY:
+	case BPF_MAP_TYPE_STACK_TRACE:
+	case BPF_MAP_TYPE_QUEUE:
+	case BPF_MAP_TYPE_STACK:
+	case BPF_MAP_TYPE_LRU_HASH:
+	case BPF_MAP_TYPE_LRU_PERCPU_HASH:
+	case BPF_MAP_TYPE_STRUCT_OPS:
+	case BPF_MAP_TYPE_CPUMAP:
+		if (!bpf_capable())
+			return -EPERM;
+		break;
+	case BPF_MAP_TYPE_SOCKMAP:
+	case BPF_MAP_TYPE_SOCKHASH:
+	case BPF_MAP_TYPE_DEVMAP:
+	case BPF_MAP_TYPE_DEVMAP_HASH:
+	case BPF_MAP_TYPE_XSKMAP:
+		if (!capable(CAP_NET_ADMIN))
+			return -EPERM;
+		break;
+	default:
+		WARN(1, "unsupported map type %d", map_type);
+		return -EPERM;
+	}
+
+	map = ops->map_alloc(attr);
 	if (IS_ERR(map))
 		return PTR_ERR(map);
+	map->ops = ops;
+	map->map_type = map_type;
 
 	err = bpf_obj_name_cpy(map->name, attr->map_name,
 			       sizeof(attr->map_name));
@@ -1931,6 +1978,11 @@ static int map_freeze(const union bpf_attr *attr)
 		return -ENOTSUPP;
 	}
 
+	if (!(map_get_sys_perms(map, f) & FMODE_CAN_WRITE)) {
+		fdput(f);
+		return -EPERM;
+	}
+
 	mutex_lock(&map->freeze_mutex);
 	if (bpf_map_write_active(map)) {
 		err = -EBUSY;
@@ -1940,10 +1992,6 @@ static int map_freeze(const union bpf_attr *attr)
 		err = -EBUSY;
 		goto err_put;
 	}
-	if (!bpf_capable()) {
-		err = -EPERM;
-		goto err_put;
-	}
 
 	WRITE_ONCE(map->frozen, true);
 err_put:
@@ -2506,7 +2554,6 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
 	struct btf *attach_btf = NULL;
 	int err;
 	char license[128];
-	bool is_gpl;
 
 	if (CHECK_ATTR(BPF_PROG_LOAD))
 		return -EINVAL;
@@ -2525,15 +2572,15 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
 	    !bpf_capable())
 		return -EPERM;
 
-	/* copy eBPF program license from user space */
-	if (strncpy_from_bpfptr(license,
-				make_bpfptr(attr->license, uattr.is_kernel),
-				sizeof(license) - 1) < 0)
-		return -EFAULT;
-	license[sizeof(license) - 1] = 0;
-
-	/* eBPF programs must be GPL compatible to use GPL-ed functions */
-	is_gpl = license_is_gpl_compatible(license);
+	/* Intent here is for unprivileged_bpf_disabled to block BPF program
+	 * creation for unprivileged users; other actions depend
+	 * on fd availability and access to bpffs, so are dependent on
+	 * object creation success. Even with unprivileged BPF disabled,
+	 * capability checks are still carried out for these
+	 * and other operations.
+	 */
+	if (sysctl_unprivileged_bpf_disabled && !bpf_capable())
+		return -EPERM;
 
 	if (attr->insn_cnt == 0 ||
 	    attr->insn_cnt > (bpf_capable() ? BPF_COMPLEXITY_LIMIT_INSNS : BPF_MAXINSNS))
@@ -2617,12 +2664,20 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size)
 			     make_bpfptr(attr->insns, uattr.is_kernel),
 			     bpf_prog_insn_size(prog)) != 0)
 		goto free_prog_sec;
+	/* copy eBPF program license from user space */
+	if (strncpy_from_bpfptr(license,
+				make_bpfptr(attr->license, uattr.is_kernel),
+				sizeof(license) - 1) < 0)
+		goto free_prog_sec;
+	license[sizeof(license) - 1] = 0;
+
+	/* eBPF programs must be GPL compatible to use GPL-ed functions */
+	prog->gpl_compatible = license_is_gpl_compatible(license) ? 1 : 0;
 
 	prog->orig_prog = NULL;
 	prog->jited = 0;
 
 	atomic64_set(&prog->aux->refcnt, 1);
-	prog->gpl_compatible = is_gpl ? 1 : 0;
 
 	if (bpf_prog_is_dev_bound(prog->aux)) {
 		err = bpf_prog_dev_bound_init(prog, attr);
@@ -2701,23 +2756,38 @@ free_prog:
 	return err;
 }
 
-#define BPF_OBJ_LAST_FIELD file_flags
+#define BPF_OBJ_LAST_FIELD path_fd
 
 static int bpf_obj_pin(const union bpf_attr *attr)
 {
-	if (CHECK_ATTR(BPF_OBJ) || attr->file_flags != 0)
+	int path_fd;
+
+	if (CHECK_ATTR(BPF_OBJ) || attr->file_flags & ~BPF_F_PATH_FD)
 		return -EINVAL;
 
-	return bpf_obj_pin_user(attr->bpf_fd, u64_to_user_ptr(attr->pathname));
+	/* path_fd has to be accompanied by BPF_F_PATH_FD flag */
+	if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd)
+		return -EINVAL;
+
+	path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD;
+	return bpf_obj_pin_user(attr->bpf_fd, path_fd,
+				u64_to_user_ptr(attr->pathname));
 }
 
 static int bpf_obj_get(const union bpf_attr *attr)
 {
+	int path_fd;
+
 	if (CHECK_ATTR(BPF_OBJ) || attr->bpf_fd != 0 ||
-	    attr->file_flags & ~BPF_OBJ_FLAG_MASK)
+	    attr->file_flags & ~(BPF_OBJ_FLAG_MASK | BPF_F_PATH_FD))
+		return -EINVAL;
+
+	/* path_fd has to be accompanied by BPF_F_PATH_FD flag */
+	if (!(attr->file_flags & BPF_F_PATH_FD) && attr->path_fd)
 		return -EINVAL;
 
-	return bpf_obj_get_user(u64_to_user_ptr(attr->pathname),
+	path_fd = attr->file_flags & BPF_F_PATH_FD ? attr->path_fd : AT_FDCWD;
+	return bpf_obj_get_user(path_fd, u64_to_user_ptr(attr->pathname),
 				attr->file_flags);
 }
 
@@ -2781,28 +2851,31 @@ static void bpf_link_put_deferred(struct work_struct *work)
 	bpf_link_free(link);
 }
 
-/* bpf_link_put can be called from atomic context, but ensures that resources
- * are freed from process context
+/* bpf_link_put might be called from atomic context. It needs to be called
+ * from sleepable context in order to acquire sleeping locks during the process.
  */
 void bpf_link_put(struct bpf_link *link)
 {
 	if (!atomic64_dec_and_test(&link->refcnt))
 		return;
 
-	if (in_atomic()) {
-		INIT_WORK(&link->work, bpf_link_put_deferred);
-		schedule_work(&link->work);
-	} else {
-		bpf_link_free(link);
-	}
+	INIT_WORK(&link->work, bpf_link_put_deferred);
+	schedule_work(&link->work);
 }
 EXPORT_SYMBOL(bpf_link_put);
 
+static void bpf_link_put_direct(struct bpf_link *link)
+{
+	if (!atomic64_dec_and_test(&link->refcnt))
+		return;
+	bpf_link_free(link);
+}
+
 static int bpf_link_release(struct inode *inode, struct file *filp)
 {
 	struct bpf_link *link = filp->private_data;
 
-	bpf_link_put(link);
+	bpf_link_put_direct(link);
 	return 0;
 }
 
@@ -2972,10 +3045,17 @@ static void bpf_tracing_link_show_fdinfo(const struct bpf_link *link,
 {
 	struct bpf_tracing_link *tr_link =
 		container_of(link, struct bpf_tracing_link, link.link);
+	u32 target_btf_id, target_obj_id;
 
+	bpf_trampoline_unpack_key(tr_link->trampoline->key,
+				  &target_obj_id, &target_btf_id);
 	seq_printf(seq,
-		   "attach_type:\t%d\n",
-		   tr_link->attach_type);
+		   "attach_type:\t%d\n"
+		   "target_obj_id:\t%u\n"
+		   "target_btf_id:\t%u\n",
+		   tr_link->attach_type,
+		   target_obj_id,
+		   target_btf_id);
 }
 
 static int bpf_tracing_link_fill_link_info(const struct bpf_link *link,
@@ -4778,7 +4858,7 @@ out_put_progs:
 	if (ret)
 		bpf_prog_put(new_prog);
 out_put_link:
-	bpf_link_put(link);
+	bpf_link_put_direct(link);
 	return ret;
 }
 
@@ -4801,7 +4881,7 @@ static int link_detach(union bpf_attr *attr)
 	else
 		ret = -EOPNOTSUPP;
 
-	bpf_link_put(link);
+	bpf_link_put_direct(link);
 	return ret;
 }
 
@@ -4871,7 +4951,7 @@ static int bpf_link_get_fd_by_id(const union bpf_attr *attr)
 
 	fd = bpf_link_new_fd(link);
 	if (fd < 0)
-		bpf_link_put(link);
+		bpf_link_put_direct(link);
 
 	return fd;
 }
@@ -4948,7 +5028,7 @@ static int bpf_iter_create(union bpf_attr *attr)
 		return PTR_ERR(link);
 
 	err = bpf_iter_new_fd(link);
-	bpf_link_put(link);
+	bpf_link_put_direct(link);
 
 	return err;
 }
@@ -5018,23 +5098,8 @@ out_prog_put:
 static int __sys_bpf(int cmd, bpfptr_t uattr, unsigned int size)
 {
 	union bpf_attr attr;
-	bool capable;
 	int err;
 
-	capable = bpf_capable() || !sysctl_unprivileged_bpf_disabled;
-
-	/* Intent here is for unprivileged_bpf_disabled to block key object
-	 * creation commands for unprivileged users; other actions depend
-	 * of fd availability and access to bpffs, so are dependent on
-	 * object creation success.  Capabilities are later verified for
-	 * operations such as load and map create, so even with unprivileged
-	 * BPF disabled, capability checks are still carried out for these
-	 * and other operations.
-	 */
-	if (!capable &&
-	    (cmd == BPF_MAP_CREATE || cmd == BPF_PROG_LOAD))
-		return -EPERM;
-
 	err = bpf_check_uarg_tail_zero(uattr, sizeof(attr), size);
 	if (err)
 		return err;
@@ -5239,9 +5304,9 @@ int kern_sys_bpf(int cmd, union bpf_attr *attr, unsigned int size)
 		}
 
 		run_ctx.bpf_cookie = 0;
-		run_ctx.saved_run_ctx = NULL;
 		if (!__bpf_prog_enter_sleepable_recur(prog, &run_ctx)) {
 			/* recursion detected */
+			__bpf_prog_exit_sleepable_recur(prog, 0, &run_ctx);
 			bpf_prog_put(prog);
 			return -EBUSY;
 		}
@@ -5394,7 +5459,8 @@ static int bpf_unpriv_handler(struct ctl_table *table, int write,
 		*(int *)table->data = unpriv_enable;
 	}
 
-	unpriv_ebpf_notify(unpriv_enable);
+	if (write)
+		unpriv_ebpf_notify(unpriv_enable);
 
 	return ret;
 }