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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: 195638b6d4
("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>
This commit is contained in:
parent
21c4e7f255
commit
07a708f0a1
@ -315,6 +315,13 @@ void fintek_8250_set_termios(struct uart_port *port, struct ktermios *termios,
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F81866_UART_CLK_14_769MHZ, F81866_UART_CLK_18_432MHZ,
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F81866_UART_CLK_24MHZ };
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/*
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* We'll use serial8250_do_set_termios() for baud = 0, otherwise It'll
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* crash on baudrate_table[i] % baud with "division by zero".
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*/
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if (!baud)
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goto exit;
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switch (pdata->pid) {
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case CHIP_ID_F81216H:
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reg = RS485;
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@ -327,8 +334,7 @@ void fintek_8250_set_termios(struct uart_port *port, struct ktermios *termios,
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dev_warn(port->dev,
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"%s: pid: %x Not support. use default set_termios.\n",
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__func__, pdata->pid);
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serial8250_do_set_termios(port, termios, old);
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return;
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goto exit;
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}
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for (i = 0; i < ARRAY_SIZE(baudrate_table); ++i) {
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@ -356,6 +362,7 @@ void fintek_8250_set_termios(struct uart_port *port, struct ktermios *termios,
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tty_termios_encode_baud_rate(termios, baud, baud);
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}
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exit:
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serial8250_do_set_termios(port, termios, old);
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}
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