f2e1de0750
commit ef1100ef20f29aec4e62abeccdb5bdbebba1e378 upstream.
When the ksz module is installed and removed using rmmod, kernel crashes
with null pointer dereferrence error. During rmmod, ksz_switch_remove
function tries to cancel the mib_read_workqueue using
cancel_delayed_work_sync routine and unregister switch from dsa.
During dsa_unregister_switch it calls ksz_mac_link_down, which in turn
reschedules the workqueue since mib_interval is non-zero.
Due to which queue executed after mib_interval and it tries to access
dp->slave. But the slave is unregistered in the ksz_switch_remove
function. Hence kernel crashes.
To avoid this crash, before canceling the workqueue, resetted the
mib_interval to 0.
v1 -> v2:
-Removed the if condition in ksz_mib_read_work
Fixes: 469b390e1ba3 ("net: dsa: microchip: use delayed_work instead of timer + work")
Signed-off-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.