Re: [syzbot] [bluetooth?] KASAN: slab-out-of-bounds Read in hci_sock_setsockopt

[Hillf Danton]

On Thu, 04 Apr 2024 23:56:28 -0700
> syzbot found the following issue on:
> 
> HEAD commit:    fe46a7dd189e Merge tag 'sound-6.9-rc1' of git://git.kernel..
> git tree:       upstream
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1777929d180000

#syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git  fe46a7dd189e

--- x/net/bluetooth/hci_sock.c
+++ y/net/bluetooth/hci_sock.c
@@ -1946,7 +1946,7 @@ static int hci_sock_setsockopt_old(struc
 
 	switch (optname) {
 	case HCI_DATA_DIR:
-		if (copy_from_sockptr(&opt, optval, sizeof(opt))) {
+		if (len < sizeof(opt) || copy_from_sockptr(&opt, optval, sizeof(opt))) {
 			err = -EFAULT;
 			break;
 		}
--