db19c91c3b
Patch series "Relocate execve() sanity checks", v2. While looking at the code paths for the proposed O_MAYEXEC flag, I saw some things that looked like they should be fixed up. exec: Change uselib(2) IS_SREG() failure to EACCES This just regularizes the return code on uselib(2). exec: Move S_ISREG() check earlier This moves the S_ISREG() check even earlier than it was already. exec: Move path_noexec() check earlier This adds the path_noexec() check to the same place as the S_ISREG() check. This patch (of 3): Change uselib(2)' S_ISREG() error return to EACCES instead of EINVAL so the behavior matches execve(2), and the seemingly documented value. The "not a regular file" failure mode of execve(2) is explicitly documented[1], but it is not mentioned in uselib(2)[2] which does, however, say that open(2) and mmap(2) errors may apply. The documentation for open(2) does not include a "not a regular file" error[3], but mmap(2) does[4], and it is EACCES. [1] http://man7.org/linux/man-pages/man2/execve.2.html#ERRORS [2] http://man7.org/linux/man-pages/man2/uselib.2.html#ERRORS [3] http://man7.org/linux/man-pages/man2/open.2.html#ERRORS [4] http://man7.org/linux/man-pages/man2/mmap.2.html#ERRORS Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Cc: Aleksa Sarai <cyphar@cyphar.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Biggers <ebiggers3@gmail.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Link: http://lkml.kernel.org/r/20200605160013.3954297-1-keescook@chromium.org Link: http://lkml.kernel.org/r/20200605160013.3954297-2-keescook@chromium.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.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.