4.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: H. Peter Anvin <h...@zytor.com> commit 991a25194097006ec1e0d2e0814ff920e59e3465 upstream. On architectures with CBAUDEX == 0 (Alpha and PowerPC), the code in tty_baudrate.c does not do any limit checking on the tty_baudrate[] array, and in fact a buffer overrun is possible on both architectures. Add a limit check to prevent that situation. This will be followed by a much bigger cleanup/simplification patch. Signed-off-by: H. Peter Anvin (Intel) <h...@zytor.com> Requested-by: Cc: Johan Hovold <jo...@kernel.org> Cc: Jiri Slaby <jsl...@suse.com> Cc: Al Viro <v...@zeniv.linux.org.uk> Cc: Richard Henderson <r...@twiddle.net> Cc: Ivan Kokshaysky <i...@jurassic.park.msu.ru> Cc: Matt Turner <matts...@gmail.com> Cc: Thomas Gleixner <t...@linutronix.de> Cc: Kate Stewart <kstew...@linuxfoundation.org> Cc: Philippe Ombredanne <pombreda...@nexb.com> Cc: Eugene Syromiatnikov <e...@redhat.com> Cc: Alan Cox <a...@lxorguk.ukuu.org.uk> Cc: stable <sta...@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- drivers/tty/tty_ioctl.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/tty/tty_ioctl.c +++ b/drivers/tty/tty_ioctl.c @@ -325,7 +325,7 @@ speed_t tty_termios_baud_rate(struct kte else cbaud += 15; } - return baud_table[cbaud]; + return cbaud >= n_baud_table ? 0 : baud_table[cbaud]; } EXPORT_SYMBOL(tty_termios_baud_rate); @@ -361,7 +361,7 @@ speed_t tty_termios_input_baud_rate(stru else cbaud += 15; } - return baud_table[cbaud]; + return cbaud >= n_baud_table ? 0 : baud_table[cbaud]; #else return tty_termios_baud_rate(termios); #endif