pps: do not crash when failed to register
With this command sequence:
the partport_pps modules causes this crash:
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: parport_detach+0x1d/0x60 [pps_parport]
Oops: 0000 [#1] SMP
The sequence that builds up to this is:
1) plip is loaded and takes the parport device for exclusive use:
plip0: Parallel port at 0x378, using IRQ 7.
2) pps_parport then fails to grab the device:
pps_parport: parallel port PPS client
parport0: cannot grant exclusive access for device pps_parport
pps_parport: couldn't register with parport0
3) rmmod of pps_parport is then killed because it tries to access
pardev->name, but pardev (taken from port->cad) is NULL.
So add a check for NULL in the test there too.
Signed-off-by: Jiri Slaby <email@example.com>
Acked-by: Rodolfo Giometti <firstname.lastname@example.org>
Signed-off-by: Andrew Morton <email@example.com>
Signed-off-by: Linus Torvalds <firstname.lastname@example.org>
1 file changed