[PATCH 3/4] tty/serial: at91: prevent null dereference in tasklet function
From: gregkh@linuxfoundation.org (Greg KH)
Date: 2014-01-08 01:11:16
Also in:
linux-serial, lkml, stable
On Tue, Jan 07, 2014 at 11:45:08AM +0100, Nicolas Ferre wrote:
From: Marek Roszko <redacted> Something asks a tasklet to be scheduled when the uart port is closed.
What is that something? Shouldn't you track that down and find the real problem here?
quoted hunk ↗ jump to hunk
Need to supress the kernel panic for now by checking if the port is NULL or not. Signed-off-by: Marek Roszko <redacted> Acked-by: Leilei Zhao <redacted> Cc: <redacted> # v3.12 Signed-off-by: Nicolas Ferre <redacted> --- drivers/tty/serial/atmel_serial.c | 4 ++++ 1 file changed, 4 insertions(+)diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c index c421d11b3d4c..6e68486c83cb 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c@@ -1360,6 +1360,10 @@ static void atmel_tasklet_func(unsigned long data) unsigned int status; unsigned int status_change; + if(!port->state || !port->state->port.tty) + /* uart has been closed */ + return;
Did you really test this? How about running it through checkpatch? thanks, greg k-h