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| author | Johan Hovold <johan@kernel.org> | 2019-01-30 10:49:34 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-01-30 11:54:01 +0100 |
| commit | a1960e0f1639cb1f7a3d94521760fc73091f6640 (patch) | |
| tree | 26e0580dd080143c2752ec4bf5aadd22173c0cf2 /drivers/staging | |
| parent | 4d95987a32db53f3beca76f8c4c8309ef6a5f192 (diff) | |
| download | linux-a1960e0f1639cb1f7a3d94521760fc73091f6640.tar.gz linux-a1960e0f1639cb1f7a3d94521760fc73091f6640.tar.bz2 linux-a1960e0f1639cb1f7a3d94521760fc73091f6640.zip | |
staging: speakup: fix tty-operation NULL derefs
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 <stable@vger.kernel.org> # 4.13
Cc: Okash Khawaja <okash.khawaja@gmail.com>
Cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging')
| -rw-r--r-- | drivers/staging/speakup/spk_ttyio.c | 6 |
1 files 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(&speakup_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(&speakup_tty_mutex); } |