net: filter: let unattached filters use sock_fprog_kern

The sk_unattached_filter_create() API is used by BPF filters that
are not directly attached or related to sockets, and are used in
team, ptp, xt_bpf, cls_bpf, etc. As such all users do their own
internal managment of obtaining filter blocks and thus already
have them in kernel memory and set up before calling into
sk_unattached_filter_create(). As a result, due to __user annotation
in sock_fprog, sparse triggers false positives (incorrect type in
assignment [different address space]) when filters are set up before
passing them to sk_unattached_filter_create(). Therefore, let
sk_unattached_filter_create() API use sock_fprog_kern to overcome
this issue.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/isdn/i4l/isdn_ppp.c

@@ -634,7 +634,7 @@ isdn_ppp_ioctl(int min, struct file *file, unsigned int cmd, unsigned long arg)
 #ifdef CONFIG_IPPP_FILTER
 	case PPPIOCSPASS:
 	{
-		struct sock_fprog fprog;
+		struct sock_fprog_kern fprog;
 		struct sock_filter *code;
 		int err, len = get_filter(argp, &code);
 
@@ -653,7 +653,7 @@ isdn_ppp_ioctl(int min, struct file *file, unsigned int cmd, unsigned long arg)
 	}
 	case PPPIOCSACTIVE:
 	{
-		struct sock_fprog fprog;
+		struct sock_fprog_kern fprog;
 		struct sock_filter *code;
 		int err, len = get_filter(argp, &code);