Ard Biesheuvel 77ac1c02d9 jump_label: Fix NULL dereference bug in __jump_label_mod_update()
Commit 1948367768 ("jump_label: Annotate entries that operate on
__init code earlier") refactored the code that manages runtime
patching of jump labels in modules that are tied to static keys
defined in other modules or in the core kernel.

In the latter case, we may iterate over the static_key_mod linked
list until we hit the entry for the core kernel, whose 'mod' field
will be NULL, and attempt to dereference it to get at its 'state'
member.

So let's add a non-NULL check: this forces the 'init' argument of
__jump_label_update() to false for static keys that are defined in
the core kernel, which is appropriate given that __init annotated
jump_label entries in the core kernel should no longer be active
at this point (i.e., when loading modules).

Fixes: 1948367768 ("jump_label: Annotate entries that operate on ...")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20181001081324.11553-1-ard.biesheuvel@linaro.org
2018-10-02 08:08:18 +02:00
2018-09-23 19:15:18 +02:00

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.
Description
No description provided
Readme 3.4 GiB
Languages
C 97%
Assembly 1%
Shell 0.6%
Rust 0.5%
Python 0.4%
Other 0.3%