ppdev: fix double-free of pp->pdev->name
free_pardevice() is called by parport_unregister_device() and already frees
pp->pdev->name, don't try to do it again.
This bug causes kernel crashes.
I found and verified this with KASAN and some added pr_emerg()s:
[ 60.316568] pp_release: pp->pdev->name == ffff88039cb264c0
[ 60.316692] free_pardevice: freeing par_dev->name at ffff88039cb264c0
[ 60.316706] pp_release: kfree(ffff88039cb264c0)
[ 60.316714] ==========================================================
[ 60.316722] BUG: Double free or freeing an invalid pointer
[ 60.316731] Unexpected shadow byte: 0xFB
[ 60.316801] Object at ffff88039cb264c0, in cache kmalloc-32 size: 32
[ 60.316813] Allocated:
[ 60.316824] PID = 1695
[ 60.316869] Freed:
[ 60.316880] PID = 1695
[ 60.316935] ==========================================================
Signed-off-by: Jann Horn <jann@thejh.net>
Acked-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 file changed