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Commit9520ed8fb8("net: dsa: use cpu_switch instead of ds[0]") replaced the use of dst->ds[0] with dst->cpu_switch since that is functionally equivalent, however, we can now run into an use after free scenario after unbinding then rebinding the switch driver. The use after free happens because we do correctly initialize dst->cpu_switch the first time we probe in dsa_cpu_parse(), then we unbind the driver: dsa_dst_unapply() is called, and we rebind again. dst->cpu_switch now points to a freed "ds" structure, and so when we finally dereference it in dsa_cpu_port_ethtool_setup(), we oops. To fix this, simply set dst->cpu_switch to NULL in dsa_dst_unapply() which guarantees that we always correctly re-assign dst->cpu_switch in dsa_cpu_parse(). Fixes:9520ed8fb8("net: dsa: use cpu_switch instead of ds[0]") Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Reviewed-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.