Re: [PATCH] Bluetooth: iso: Fix UAF on iso_sock_disconn

[Paul Menzel <pmenzel@molgen.mpg.de>]

Dear Yang,


Thank you for your patch.

Am 05.11.25 um 10:02 schrieb Yang Li via B4 Relay:
> From: Yang Li <yang.li@amlogic.com>
> 
> kernel panic: Unable to handle kernel read from unreadable
> memory at virtual address 00000000000003d8

No line break needed in pasted logs.

> 
> Call trace:
>   iso_sock_disconn+0x110/0x1c8
>   __iso_sock_close+0x50/0x164
>   iso_sock_release+0x48/0xf0
>   __sock_release+0x40/0xb4
>   sock_close+0x18/0x28
>   __fput+0xd8/0x28c
>   __fput_sync+0x50/0x5c
>   __arm64_sys_close+0x38/0x7c
>   invoke_syscall+0x48/0x118
>   el0_svc_common.constprop.0+0x40/0xe0
>   do_el0_svc_compat+0x1c/0x34
>   el0_svc_compat+0x30/0x88
>   el0t_32_sync_handler+0x90/0x140
>   el0t_32_sync+0x198/0x19c

Please add a paragraph about this problem, and how `iso_pi(sk)->conn` 
can be NULL.

> Signed-off-by: Yang Li <yang.li@amlogic.com>
> ---
>   net/bluetooth/iso.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/net/bluetooth/iso.c b/net/bluetooth/iso.c
> index 74ec7d125c88..89c7700ceb81 100644
> --- a/net/bluetooth/iso.c
> +++ b/net/bluetooth/iso.c
> @@ -838,14 +838,14 @@ static void __iso_sock_close(struct sock *sk)
>   	case BT_CONNECT:
>   	case BT_CONNECTED:
>   	case BT_CONFIG:
> -		if (iso_pi(sk)->conn->hcon)
> +		if (iso_pi(sk)->conn && iso_pi(sk)->conn->hcon)
>   			iso_sock_disconn(sk);
>   		else
>   			iso_chan_del(sk, ECONNRESET);
>   		break;
>   
>   	case BT_CONNECT2:
> -		if (iso_pi(sk)->conn->hcon &&
> +		if (iso_pi(sk)->conn && iso_pi(sk)->conn->hcon &&
>   		    (test_bit(HCI_CONN_PA_SYNC, &iso_pi(sk)->conn->hcon->flags) ||
>   		    test_bit(HCI_CONN_PA_SYNC_FAILED, &iso_pi(sk)->conn->hcon->flags)))
>   			iso_sock_disconn(sk);

This diff looks fine.


Kind regards,

Paul