[PATCH] Bluetooth: fix oob in hci_sock_setsockopt

[PATCH] Bluetooth: fix oob in hci_sock_setsockopt

[Edward Adam Davis]

If len < sizeof(opt) it will trigger oob, so take the min of them.

Reported-by: syzbot+837ba09d9db969068367@syzkaller.appspotmail.com
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
---
 net/bluetooth/hci_sock.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c
index 4ee1b976678b..cee7ec1adbd2 100644
--- a/net/bluetooth/hci_sock.c
+++ b/net/bluetooth/hci_sock.c
@@ -1946,7 +1946,7 @@ static int hci_sock_setsockopt_old(struct socket *sock, int level, int optname,
 
 	switch (optname) {
 	case HCI_DATA_DIR:
-		if (copy_from_sockptr(&opt, optval, sizeof(opt))) {
+		if (copy_from_sockptr(&opt, optval, min_t(int, sizeof(opt), len))) {
 			err = -EFAULT;
 			break;
 		}
-- 
2.43.0

Re: [PATCH] Bluetooth: fix oob in hci_sock_setsockopt

[Luiz Augusto von Dentz]

Hi Edward,

On Tue, Apr 9, 2024 at 9:42 AM Edward Adam Davis <eadavis@qq.com> wrote:
>
> If len < sizeof(opt) it will trigger oob, so take the min of them.
>
> Reported-by: syzbot+837ba09d9db969068367@syzkaller.appspotmail.com
> Signed-off-by: Edward Adam Davis <eadavis@qq.com>
> ---
>  net/bluetooth/hci_sock.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c
> index 4ee1b976678b..cee7ec1adbd2 100644
> --- a/net/bluetooth/hci_sock.c
> +++ b/net/bluetooth/hci_sock.c
> @@ -1946,7 +1946,7 @@ static int hci_sock_setsockopt_old(struct socket *sock, int level, int optname,
>
>         switch (optname) {
>         case HCI_DATA_DIR:
> -               if (copy_from_sockptr(&opt, optval, sizeof(opt))) {
> +               if (copy_from_sockptr(&opt, optval, min_t(int, sizeof(opt), len))) {
>                         err = -EFAULT;
>                         break;
>                 }
> --
> 2.43.0

https://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth-next.git/commit/?id=35d2c39b23fffa3d5a216142cc51d86354024363


-- 
Luiz Augusto von Dentz

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

[syzbot]

syzbot has bisected this issue to:

commit 3505cb9fa26cfec9512744466e754a8cbc2365b0
Author: Jiri Olsa <jolsa@kernel.org>
Date:   Wed Aug 9 08:34:14 2023 +0000

    bpf: Add attach_type checks under bpf_prog_attach_check_attach_type

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=158aedbc980000
start commit:   fe46a7dd189e Merge tag 'sound-6.9-rc1' of git://git.kernel..
git tree:       upstream
final oops:     https://syzkaller.appspot.com/x/report.txt?x=178aedbc980000
console output: https://syzkaller.appspot.com/x/log.txt?x=138aedbc980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=4d90a36f0cab495a
dashboard link: https://syzkaller.appspot.com/bug?extid=837ba09d9db969068367
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=15807005180000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1777929d180000

Reported-by: syzbot+837ba09d9db969068367@syzkaller.appspotmail.com
Fixes: 3505cb9fa26c ("bpf: Add attach_type checks under bpf_prog_attach_check_attach_type")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection