* [PATCH] tty: Fix lookahead_buf crash with serdev
@ 2022-08-16 7:11 Vincent Whitchurch
2022-08-16 7:21 ` Ilpo Järvinen
0 siblings, 1 reply; 2+ messages in thread
From: Vincent Whitchurch @ 2022-08-16 7:11 UTC (permalink / raw)
To: Greg Kroah-Hartman, Jiri Slaby
Cc: kernel, Vincent Whitchurch, Andy Shevchenko, Ilpo Järvinen,
linux-kernel
Do not follow a NULL pointer if the tty_port_client_operations does not
implement the ->lookahead_buf() callback, which is the case with
serdev's ttyport.
Fixes: 6bb6fa6908ebd3 ("tty: Implement lookahead to process XON/XOFF timely")
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
---
drivers/tty/tty_buffer.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
index 9fdecc795b6b..a1c97d4a45fb 100644
--- a/drivers/tty/tty_buffer.c
+++ b/drivers/tty/tty_buffer.c
@@ -493,7 +493,8 @@ static void lookahead_bufs(struct tty_port *port, struct tty_buffer *head)
if (~head->flags & TTYB_NORMAL)
f = flag_buf_ptr(head, head->lookahead);
- port->client_ops->lookahead_buf(port, p, f, count);
+ if (port->client_ops->lookahead_buf)
+ port->client_ops->lookahead_buf(port, p, f, count);
head->lookahead += count;
}
}
--
2.34.1
^ permalink raw reply related [flat|nested] 2+ messages in thread* Re: [PATCH] tty: Fix lookahead_buf crash with serdev
2022-08-16 7:11 [PATCH] tty: Fix lookahead_buf crash with serdev Vincent Whitchurch
@ 2022-08-16 7:21 ` Ilpo Järvinen
0 siblings, 0 replies; 2+ messages in thread
From: Ilpo Järvinen @ 2022-08-16 7:21 UTC (permalink / raw)
To: Vincent Whitchurch
Cc: Greg Kroah-Hartman, Jiri Slaby, kernel, Andy Shevchenko, LKML
On Tue, 16 Aug 2022, Vincent Whitchurch wrote:
> Do not follow a NULL pointer if the tty_port_client_operations does not
> implement the ->lookahead_buf() callback, which is the case with
> serdev's ttyport.
>
> Fixes: 6bb6fa6908ebd3 ("tty: Implement lookahead to process XON/XOFF timely")
> Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
> ---
> drivers/tty/tty_buffer.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
> index 9fdecc795b6b..a1c97d4a45fb 100644
> --- a/drivers/tty/tty_buffer.c
> +++ b/drivers/tty/tty_buffer.c
> @@ -493,7 +493,8 @@ static void lookahead_bufs(struct tty_port *port, struct tty_buffer *head)
> if (~head->flags & TTYB_NORMAL)
> f = flag_buf_ptr(head, head->lookahead);
>
> - port->client_ops->lookahead_buf(port, p, f, count);
> + if (port->client_ops->lookahead_buf)
> + port->client_ops->lookahead_buf(port, p, f, count);
While this works, I'd put the preceeding calculations of p and f into the
same block as they just prep parameters for the call.
> head->lookahead += count;
> }
> }
>
--
i.
^ permalink raw reply [flat|nested] 2+ messages in thread
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2022-08-16 7:11 [PATCH] tty: Fix lookahead_buf crash with serdev Vincent Whitchurch
2022-08-16 7:21 ` Ilpo Järvinen
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