backport changeset f41ced8f108cc80f16509b907cd7ac93944459bc

From: Mauro Carvalho Chehab <mchehab@redhat.com>

Author: Laurent Pinchart <laurent.pinchart@skynet.be>

    Check fops_get() return value

    Several subsystem open handlers dereference the fops_get() return value
    without checking it for nullness.  This opens a race condition between the
    open handler and module unloading.

    A module can be marked as being unloaded (MODULE_STATE_GOING) before its
    exit function is called and gets the chance to unregister the driver.
    During that window open handlers can still be called, and fops_get() will
    fail in try_module_get() and return a NULL pointer.

    This change checks the fops_get() return value and returns -ENODEV if NULL.

kernel-sync:

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

0 files changed, 0 insertions, 0 deletions