53048788d6
[ Upstream commit e6b44ce1925a8329a937c57f0d60ba0d9bb5d226 ]
The new __must_check annotation on __copy_from_user() successfully
identified some code that has lacked the check since at least
linux-2.1.73:
arch/x86/math-emu/reg_ld_str.c:88:2: error: ignoring return value of \
function declared with 'warn_unused_result' attribute [-Werror,-Wunused-result]
__copy_from_user(sti_ptr, s, 10);
^~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~
arch/x86/math-emu/reg_ld_str.c:1129:2: error: ignoring return value of \
function declared with 'warn_unused_result' attribute [-Werror,-Wunused-result]
__copy_from_user(register_base + offset, s, other);
^~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arch/x86/math-emu/reg_ld_str.c:1131:3: error: ignoring return value of \
function declared with 'warn_unused_result' attribute [-Werror,-Wunused-result]
__copy_from_user(register_base, s + other, offset);
^~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In addition, the get_user()/put_user() helpers do not enforce a return
value check, but actually still require one. These have been missing for
even longer.
Change the internal wrappers around get_user()/put_user() to force
a signal and add a corresponding wrapper around __copy_from_user()
to check all such cases.
[ bp: Break long lines. ]
Fixes: 257e458057e5 ("Import 2.1.73")
Fixes: 9dd819a15162 ("uaccess: add missing __must_check attributes")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Bill Metzenthen <billm@melbpc.org.au>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191001142344.1274185-1-arnd@arndb.de
Signed-off-by: Sasha Levin <sashal@kernel.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.