Re: [PATCH] staging: speakup: fix tty-operation NULL derefs

2019-01-30 Thread Samuel Thibault
Johan Hovold, le mer. 30 janv. 2019 10:49:34 +0100, a ecrit:
> The send_xchar() and tiocmset() tty operations are optional. Add the
> missing sanity checks to prevent user-space triggerable NULL-pointer
> dereferences.
> 
> Fixes: 6b9ad1c742bf ("staging: speakup: add send_xchar, tiocmset and input 
> functionality for tty")
> Cc: stable  # 4.13
> Cc: Okash Khawaja 
> Cc: Samuel Thibault 
> Signed-off-by: Johan Hovold 

Indeed.

Reviewed-by: Samuel Thibault 

> ---
>  drivers/staging/speakup/spk_ttyio.c | 6 --
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/staging/speakup/spk_ttyio.c 
> b/drivers/staging/speakup/spk_ttyio.c
> index c92bbd05516e..005de0024dd4 100644
> --- a/drivers/staging/speakup/spk_ttyio.c
> +++ b/drivers/staging/speakup/spk_ttyio.c
> @@ -265,7 +265,8 @@ static void spk_ttyio_send_xchar(char ch)
>   return;
>   }
>  
> - speakup_tty->ops->send_xchar(speakup_tty, ch);
> + if (speakup_tty->ops->send_xchar)
> + speakup_tty->ops->send_xchar(speakup_tty, ch);
>   mutex_unlock(_tty_mutex);
>  }
>  
> @@ -277,7 +278,8 @@ static void spk_ttyio_tiocmset(unsigned int set, unsigned 
> int clear)
>   return;
>   }
>  
> - speakup_tty->ops->tiocmset(speakup_tty, set, clear);
> + if (speakup_tty->ops->tiocmset)
> + speakup_tty->ops->tiocmset(speakup_tty, set, clear);
>   mutex_unlock(_tty_mutex);
>  }
>  
> -- 
> 2.20.1
> 

-- 
Samuel
R: Parce que ça renverse bêtement l'ordre naturel de lecture!
Q: Mais pourquoi citer en fin d'article est-il si effroyable?
R: Citer en fin d'article
Q: Quelle est la chose la plus désagréable sur les groupes de news?
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[PATCH] staging: speakup: fix tty-operation NULL derefs

2019-01-30 Thread Johan Hovold
The send_xchar() and tiocmset() tty operations are optional. Add the
missing sanity checks to prevent user-space triggerable NULL-pointer
dereferences.

Fixes: 6b9ad1c742bf ("staging: speakup: add send_xchar, tiocmset and input 
functionality for tty")
Cc: stable  # 4.13
Cc: Okash Khawaja 
Cc: Samuel Thibault 
Signed-off-by: Johan Hovold 
---
 drivers/staging/speakup/spk_ttyio.c | 6 --
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/speakup/spk_ttyio.c 
b/drivers/staging/speakup/spk_ttyio.c
index c92bbd05516e..005de0024dd4 100644
--- a/drivers/staging/speakup/spk_ttyio.c
+++ b/drivers/staging/speakup/spk_ttyio.c
@@ -265,7 +265,8 @@ static void spk_ttyio_send_xchar(char ch)
return;
}
 
-   speakup_tty->ops->send_xchar(speakup_tty, ch);
+   if (speakup_tty->ops->send_xchar)
+   speakup_tty->ops->send_xchar(speakup_tty, ch);
mutex_unlock(_tty_mutex);
 }
 
@@ -277,7 +278,8 @@ static void spk_ttyio_tiocmset(unsigned int set, unsigned 
int clear)
return;
}
 
-   speakup_tty->ops->tiocmset(speakup_tty, set, clear);
+   if (speakup_tty->ops->tiocmset)
+   speakup_tty->ops->tiocmset(speakup_tty, set, clear);
mutex_unlock(_tty_mutex);
 }
 
-- 
2.20.1

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