[PATCH resend 1/2] tty: omap-serial: fix division by zero
If the chosen baud rate is large enough (e.g. 3.5 megabaud), the
calculated n values in serial_omap_is_baud_mode16() may become 0. This
causes a division by zero when calculating the difference between
calculated and desired baud rates. To prevent this, cap the n13 and n16
values on 1.
Division by zero in kernel.
[c00132e0] (unwind_backtrace) from [c00112ec] (show_stack+0x10/0x14)
[c00112ec] (show_stack) from [c01ed7bc] (Ldiv0+0x8/0x10)
[c01ed7bc] (Ldiv0) from [c023805c] (serial_omap_baud_is_mode16+0x4c/0x68)
[c023805c] (serial_omap_baud_is_mode16) from [c02396b4]
(serial_omap_set_termios+0x90/0x8d8)
[c02396b4] (serial_omap_set_termios) from [c0230a0c]
(uart_change_speed+0xa4/0xa8)
[c0230a0c] (uart_change_speed) from [c0231798] (uart_set_termios+0xa0/0x1fc)
[c0231798] (uart_set_termios) from [c022bb44] (tty_set_termios+0x248/0x2c0)
[c022bb44] (tty_set_termios) from [c022c17c] (set_termios+0x248/0x29c)
[c022c17c] (set_termios) from [c022c3e4] (tty_mode_ioctl+0x1c8/0x4e8)
[c022c3e4] (tty_mode_ioctl) from [c0227e70] (tty_ioctl+0xa94/0xb18)
[c0227e70] (tty_ioctl) from [c00cf45c] (do_vfs_ioctl+0x4a0/0x560)
[c00cf45c] (do_vfs_ioctl) from [c00cf568] (SyS_ioctl+0x4c/0x74)
[c00cf568] (SyS_ioctl) from [c000e480] (ret_fast_syscall+0x0/0x30)
Signed-off-by: Frans Klaver frans.kla...@xsens.com
---
Resend to add sta...@vger.kernel.org to CC. As far as I know, this applies to
v3.9 and up.
Thanks,
Frans
drivers/tty/serial/omap-serial.c | 12 ++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index d017cec..e454b7c 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -254,8 +254,16 @@ serial_omap_baud_is_mode16(struct uart_port *port,
unsigned int baud)
{
unsigned int n13 = port-uartclk / (13 * baud);
unsigned int n16 = port-uartclk / (16 * baud);
- int baudAbsDiff13 = baud - (port-uartclk / (13 * n13));
- int baudAbsDiff16 = baud - (port-uartclk / (16 * n16));
+ int baudAbsDiff13;
+ int baudAbsDiff16;
+
+ if (n13 == 0)
+ n13 = 1;
+ if (n16 == 0)
+ n16 = 1;
+
+ baudAbsDiff13 = baud - (port-uartclk / (13 * n13));
+ baudAbsDiff16 = baud - (port-uartclk / (16 * n16));
if (baudAbsDiff13 0)
baudAbsDiff13 = -baudAbsDiff13;
if (baudAbsDiff16 0)
--
2.1.0
--
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Re: [PATCH resend 1/2] tty: omap-serial: fix division by zero
On Thu, Sep 25, 2014 at 11:19:51AM +0200, Frans Klaver wrote: If the chosen baud rate is large enough (e.g. 3.5 megabaud), the calculated n values in serial_omap_is_baud_mode16() may become 0. This causes a division by zero when calculating the difference between calculated and desired baud rates. To prevent this, cap the n13 and n16 values on 1. Division by zero in kernel. [c00132e0] (unwind_backtrace) from [c00112ec] (show_stack+0x10/0x14) [c00112ec] (show_stack) from [c01ed7bc] (Ldiv0+0x8/0x10) [c01ed7bc] (Ldiv0) from [c023805c] (serial_omap_baud_is_mode16+0x4c/0x68) [c023805c] (serial_omap_baud_is_mode16) from [c02396b4] (serial_omap_set_termios+0x90/0x8d8) [c02396b4] (serial_omap_set_termios) from [c0230a0c] (uart_change_speed+0xa4/0xa8) [c0230a0c] (uart_change_speed) from [c0231798] (uart_set_termios+0xa0/0x1fc) [c0231798] (uart_set_termios) from [c022bb44] (tty_set_termios+0x248/0x2c0) [c022bb44] (tty_set_termios) from [c022c17c] (set_termios+0x248/0x29c) [c022c17c] (set_termios) from [c022c3e4] (tty_mode_ioctl+0x1c8/0x4e8) [c022c3e4] (tty_mode_ioctl) from [c0227e70] (tty_ioctl+0xa94/0xb18) [c0227e70] (tty_ioctl) from [c00cf45c] (do_vfs_ioctl+0x4a0/0x560) [c00cf45c] (do_vfs_ioctl) from [c00cf568] (SyS_ioctl+0x4c/0x74) [c00cf568] (SyS_ioctl) from [c000e480] (ret_fast_syscall+0x0/0x30) Signed-off-by: Frans Klaver frans.kla...@xsens.com --- Resend to add sta...@vger.kernel.org to CC. As far as I know, this applies to v3.9 and up. formletter This is not the correct way to submit patches for inclusion in the stable kernel tree. Please read Documentation/stable_kernel_rules.txt for how to do this properly. /formletter I'll take care of this, but go read that file for your next time... greg k-h -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH resend 1/2] tty: omap-serial: fix division by zero
On Thu, Sep 25, 2014 at 12:16:28PM +0200, Greg Kroah-Hartman wrote: On Thu, Sep 25, 2014 at 11:19:51AM +0200, Frans Klaver wrote: If the chosen baud rate is large enough (e.g. 3.5 megabaud), the calculated n values in serial_omap_is_baud_mode16() may become 0. This causes a division by zero when calculating the difference between calculated and desired baud rates. To prevent this, cap the n13 and n16 values on 1. Division by zero in kernel. [c00132e0] (unwind_backtrace) from [c00112ec] (show_stack+0x10/0x14) [c00112ec] (show_stack) from [c01ed7bc] (Ldiv0+0x8/0x10) [c01ed7bc] (Ldiv0) from [c023805c] (serial_omap_baud_is_mode16+0x4c/0x68) [c023805c] (serial_omap_baud_is_mode16) from [c02396b4] (serial_omap_set_termios+0x90/0x8d8) [c02396b4] (serial_omap_set_termios) from [c0230a0c] (uart_change_speed+0xa4/0xa8) [c0230a0c] (uart_change_speed) from [c0231798] (uart_set_termios+0xa0/0x1fc) [c0231798] (uart_set_termios) from [c022bb44] (tty_set_termios+0x248/0x2c0) [c022bb44] (tty_set_termios) from [c022c17c] (set_termios+0x248/0x29c) [c022c17c] (set_termios) from [c022c3e4] (tty_mode_ioctl+0x1c8/0x4e8) [c022c3e4] (tty_mode_ioctl) from [c0227e70] (tty_ioctl+0xa94/0xb18) [c0227e70] (tty_ioctl) from [c00cf45c] (do_vfs_ioctl+0x4a0/0x560) [c00cf45c] (do_vfs_ioctl) from [c00cf568] (SyS_ioctl+0x4c/0x74) [c00cf568] (SyS_ioctl) from [c000e480] (ret_fast_syscall+0x0/0x30) Signed-off-by: Frans Klaver frans.kla...@xsens.com --- Resend to add sta...@vger.kernel.org to CC. As far as I know, this applies to v3.9 and up. formletter This is not the correct way to submit patches for inclusion in the stable kernel tree. Please read Documentation/stable_kernel_rules.txt for how to do this properly. /formletter I'll take care of this, but go read that file for your next time... Ah, right. I'll heed that next time. Thanks for taking care of it. Frans -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
