300eec7c0a
ic_nameservers, which stores the list of name servers discovered by ipconfig, is initialised (i.e. has all of its elements set to NONE, or 0xffffffff) by ic_nameservers_predef() in the following scenarios: - before the "ip=" and "nfsaddrs=" kernel command line parameters are parsed (in ip_auto_config_setup()); - before autoconfiguring via DHCP or BOOTP (in ic_bootp_init()), in order to clear any values that may have been set after parsing "ip=" or "nfsaddrs=" and are no longer needed. This means that ic_nameservers_predef() is not called when neither "ip=" nor "nfsaddrs=" is specified on the kernel command line. In this scenario, every element in ic_nameservers remains set to 0x00000000, which is indistinguishable from ANY and causes pnp_seq_show() to write the following (bogus) information to /proc/net/pnp: #MANUAL nameserver 0.0.0.0 nameserver 0.0.0.0 nameserver 0.0.0.0 This is potentially problematic for systems that blindly link /etc/resolv.conf to /proc/net/pnp. Ensure that ic_nameservers is also initialised when neither "ip=" nor "nfsaddrs=" are specified by calling ic_nameservers_predef() in ip_auto_config(), but only when ip_auto_config_setup() was not called earlier. This causes the following to be written to /proc/net/pnp, and is consistent with what gets written when ipconfig is configured manually but no name servers are specified on the kernel command line: #MANUAL Signed-off-by: Chris Novakovic <chris@chrisn.me.uk> 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.
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.