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| author | Johan Hovold <johan@kernel.org> | 2019-01-30 10:49:34 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-02-12 19:46:12 +0100 |
| commit | 04f2d3f8be890be594ee936d8184af54662864b3 (patch) | |
| tree | ec36273ea4d12f39a0ee3d3521ce0e37ce8ecc20 | |
| parent | f8b500d1097d05d99209732e4034e0d2bff07185 (diff) | |
| download | linux-exynos-04f2d3f8be890be594ee936d8184af54662864b3.tar.gz linux-exynos-04f2d3f8be890be594ee936d8184af54662864b3.tar.bz2 linux-exynos-04f2d3f8be890be594ee936d8184af54662864b3.zip | |
staging: speakup: fix tty-operation NULL derefs
commit a1960e0f1639cb1f7a3d94521760fc73091f6640 upstream.
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>
| -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 4d7d8f2f66ea..71edd3cfe684 100644 --- a/drivers/staging/speakup/spk_ttyio.c +++ b/drivers/staging/speakup/spk_ttyio.c @@ -246,7 +246,8 @@ 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); } @@ -258,7 +259,8 @@ 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); } |