diff options
| author | Jessica Yu <jeyu@kernel.org> | 2019-07-23 15:26:28 +0200 |
|---|---|---|
| committer | Jessica Yu <jeyu@kernel.org> | 2019-07-30 10:35:23 +0200 |
| commit | 38f054d549a869f22a02224cd276a27bf14b6171 (patch) | |
| tree | 4318fc573fcb3d013d681c45e7a781f36e8dd13d | |
| parent | 5f9e832c137075045d15cd6899ab0505cfb2ca4b (diff) | |
| download | linux-38f054d549a869f22a02224cd276a27bf14b6171.tar.bz2 | |
modules: always page-align module section allocations
Some arches (e.g., arm64, x86) have moved towards non-executable
module_alloc() allocations for security hardening reasons. That means
that the module loader will need to set the text section of a module to
executable, regardless of whether or not CONFIG_STRICT_MODULE_RWX is set.
When CONFIG_STRICT_MODULE_RWX=y, module section allocations are always
page-aligned to handle memory rwx permissions. On some arches with
CONFIG_STRICT_MODULE_RWX=n however, when setting the module text to
executable, the BUG_ON() in frob_text() gets triggered since module
section allocations are not page-aligned when CONFIG_STRICT_MODULE_RWX=n.
Since the set_memory_* API works with pages, and since we need to call
set_memory_x() regardless of whether CONFIG_STRICT_MODULE_RWX is set, we
might as well page-align all module section allocations for ease of
managing rwx permissions of module sections (text, rodata, etc).
Fixes: 2eef1399a866 ("modules: fix BUG when load module with rodata=n")
Reported-by: Martin Kaiser <lists@kaiser.cx>
Reported-by: Bartosz Golaszewski <brgl@bgdev.pl>
Tested-by: David Lechner <david@lechnology.com>
Tested-by: Martin Kaiser <martin@kaiser.cx>
Tested-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
| -rw-r--r-- | kernel/module.c | 7 |
1 files changed, 1 insertions, 6 deletions
diff --git a/kernel/module.c b/kernel/module.c index 5933395af9a0..cd8df516666d 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -64,14 +64,9 @@ /* * Modules' sections will be aligned on page boundaries - * to ensure complete separation of code and data, but - * only when CONFIG_STRICT_MODULE_RWX=y + * to ensure complete separation of code and data */ -#ifdef CONFIG_STRICT_MODULE_RWX # define debug_align(X) ALIGN(X, PAGE_SIZE) -#else -# define debug_align(X) (X) -#endif /* If this is set, the section belongs in the init part of the module */ #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1)) |