ic_close_dev contains a generalization of the logic to not close a network interface if it's the host port for a DSA switch. This logic is disguised behind an iteration through the lowers of ic_dev in ic_close_dev. When no interface for ipconfig can be found, ic_dev is NULL, and ic_close_dev: - dereferences a NULL pointer when assigning selected_dev - would attempt to search through the lower interfaces of a NULL net_device pointer So we should protect against that case. The "lower_dev" iterator variable was shortened to "lower" in order to keep the 80 character limit. Fixes: f68cbaed67cb ("net: ipconfig: avoid use-after-free in ic_close_devs") Fixes: 46acf7bdbc72 ("Revert "net: ipv4: handle DSA enabled master network devices"") Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Tested-by: Heiko Thiery <heiko.thiery@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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.
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