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From: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Date: Tue, 9 Apr 2024 10:11:50 -0400
Message-ID: <CABBYNZ+4x2XxgL2eGYU0dd1+83quVajEk-bAqt3FG7wPx+=nFg@mail.gmail.com>
Subject: Re: [PATCH] Bluetooth: fix oob in rfcomm_sock_setsockopt
To: Edward Adam Davis <eadavis@qq.com>
Cc: eric.dumazet@gmail.com, edumazet@google.com, johan.hedberg@gmail.com, 
	linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org, 
	marcel@holtmann.org, netdev@vger.kernel.org, pmenzel@molgen.mpg.de, 
	syzbot+d4ecae01a53fd9b42e7d@syzkaller.appspotmail.com, 
	syzkaller-bugs@googlegroups.com
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Hi Edward,

On Tue, Apr 9, 2024 at 9:36=E2=80=AFAM Edward Adam Davis <eadavis@qq.com> w=
rote:
>
> If optlen < sizeof(u32) it will trigger oob, so take the min of them.
>
> Reported-by: syzbot+d4ecae01a53fd9b42e7d@syzkaller.appspotmail.com
> Signed-off-by: Edward Adam Davis <eadavis@qq.com>
> ---
>  net/bluetooth/rfcomm/sock.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c
> index b54e8a530f55..42c55c756b51 100644
> --- a/net/bluetooth/rfcomm/sock.c
> +++ b/net/bluetooth/rfcomm/sock.c
> @@ -629,7 +629,7 @@ static int rfcomm_sock_setsockopt_old(struct socket *=
sock, int optname,
>
>         switch (optname) {
>         case RFCOMM_LM:
> -               if (copy_from_sockptr(&opt, optval, sizeof(u32))) {
> +               if (copy_from_sockptr(&opt, optval, min_t(int, sizeof(u32=
), optlen))) {
>                         err =3D -EFAULT;
>                         break;
>                 }
> --
> 2.43.0

This has been dealt with already:

https://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next.gi=
t/commit/?id=3Dee77912bc0bbd78fceb785a81cc9108fa954982f


--=20
Luiz Augusto von Dentz