diff options
| author | Ji-Ze Hong (Peter Hong) <hpeter@gmail.com> | 2017-11-08 11:05:46 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-11-08 13:09:35 +0100 |
| commit | 07a708f0a16f040b319db647452bcb8884cd04be (patch) | |
| tree | 2c677e48e42007574c7210fc28e2f8c37d97a54d | |
| parent | 21c4e7f255e38620bb4c5d1119c64114ab280e2e (diff) | |
serial: 8250_fintek: Fix crash with baud rate B0
The 8250_fintek.c is support the Fintek F81866/F81216 with dynamic clock.
But It'll generate "division by zero" exception and crash in
fintek_8250_set_termios() with baud rate 0 on baudrate_table[i] % baud.
It can be tested with following C code:
...
struct termios options;
tcgetattr(fd, &options);
...
options.c_cflag = CS8 | CREAD; /* baud rate 0 */
tcsetattr(fd, TCSANOW, &options);
tcflush(fd, TCIOFLUSH);
Fixes: 195638b6d44f ("serial: 8250_fintek: UART dynamic clocksource on Fintek F81866")
Reported-by: Lukas Redlinger <rel+kernel@agilox.net>
Cc: Lukas Redlinger <rel+kernel@agilox.net>
Signed-off-by: Ji-Ze Hong (Peter Hong) <hpeter+linux_kernel@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/serial/8250/8250_fintek.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/drivers/tty/serial/8250/8250_fintek.c b/drivers/tty/serial/8250/8250_fintek.c index ae7d86e44b76..79a4958b3f5c 100644 --- a/drivers/tty/serial/8250/8250_fintek.c +++ b/drivers/tty/serial/8250/8250_fintek.c @@ -315,6 +315,13 @@ void fintek_8250_set_termios(struct uart_port *port, struct ktermios *termios, F81866_UART_CLK_14_769MHZ, F81866_UART_CLK_18_432MHZ, F81866_UART_CLK_24MHZ }; + /* + * We'll use serial8250_do_set_termios() for baud = 0, otherwise It'll + * crash on baudrate_table[i] % baud with "division by zero". + */ + if (!baud) + goto exit; + switch (pdata->pid) { case CHIP_ID_F81216H: reg = RS485; @@ -327,8 +334,7 @@ void fintek_8250_set_termios(struct uart_port *port, struct ktermios *termios, dev_warn(port->dev, "%s: pid: %x Not support. use default set_termios.\n", __func__, pdata->pid); - serial8250_do_set_termios(port, termios, old); - return; + goto exit; } for (i = 0; i < ARRAY_SIZE(baudrate_table); ++i) { @@ -356,6 +362,7 @@ void fintek_8250_set_termios(struct uart_port *port, struct ktermios *termios, tty_termios_encode_baud_rate(termios, baud, baud); } +exit: serial8250_do_set_termios(port, termios, old); } |