From d85114a0a131e839070728f2d7bc253a9bfa8eb8 Mon Sep 17 00:00:00 2001 From: "H. Peter Anvin" Date: Mon, 22 Oct 2018 09:19:04 -0700 Subject: [PATCH] termios, tty/tty_baudrate.c: fix buffer overrun 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) Requested-by: Cc: Johan Hovold Cc: Jiri Slaby Cc: Al Viro Cc: Richard Henderson Cc: Ivan Kokshaysky Cc: Matt Turner Cc: Thomas Gleixner Cc: Kate Stewart Cc: Philippe Ombredanne Cc: Eugene Syromiatnikov Cc: Alan Cox Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/tty/tty_baudrate.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/tty/tty_baudrate.c b/drivers/tty/tty_baudrate.c index ebc797fc1afd..42e5683147d5 100644 --- a/drivers/tty/tty_baudrate.c +++ b/drivers/tty/tty_baudrate.c @@ -76,7 +76,7 @@ speed_t tty_termios_baud_rate(struct ktermios *termios) else cbaud += 15; } - return baud_table[cbaud]; + return cbaud >= n_baud_table ? 0 : baud_table[cbaud]; } EXPORT_SYMBOL(tty_termios_baud_rate); @@ -112,7 +112,7 @@ speed_t tty_termios_input_baud_rate(struct ktermios *termios) else cbaud += 15; } - return baud_table[cbaud]; + return cbaud >= n_baud_table ? 0 : baud_table[cbaud]; #else return tty_termios_baud_rate(termios); #endif -- 2.20.1