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* module: Don't ignore errors from set_memory_XX()Christophe Leroy2024-02-161-15/+36
| | | | | | | | | | | | | | | | | | | | set_memory_ro(), set_memory_nx(), set_memory_x() and other helpers can fail and return an error. In that case the memory might not be protected as expected and the module loading has to be aborted to avoid security issues. Check return value of all calls to set_memory_XX() and handle error if any. Add a check to not call set_memory_XX() on NULL pointers as some architectures may not like it allthough numpages is always 0 in that case. This also avoid a useless call to set_vm_flush_reset_perms(). Link: https://github.com/KSPP/linux/issues/7 Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
* modules: Remove #ifdef CONFIG_STRICT_MODULE_RWX around rodata_enabledChristophe Leroy2024-02-021-5/+1
| | | | | | | | Now that rodata_enabled is declared at all time, the #ifdef CONFIG_STRICT_MODULE_RWX can be removed. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
* module: Change module_enable_{nx/x/ro}() to more explicit namesChristophe Leroy2024-01-291-3/+3
| | | | | | | | | | | It's a bit puzzling to see a call to module_enable_nx() followed by a call to module_enable_x(). This is because one applies on text while the other applies on data. Change name to make that more clear. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
* module: Use set_memory_rox()Christophe Leroy2024-01-291-5/+7
| | | | | | | | | | | | | A couple of architectures seem concerned about calling set_memory_ro() and set_memory_x() too frequently and have implemented a version of set_memory_rox(), see commit 60463628c9e0 ("x86/mm: Implement native set_memory_rox()") and commit 22e99fa56443 ("s390/mm: implement set_memory_rox()") Use set_memory_rox() in modules when STRICT_MODULES_RWX is set. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
* module: replace module_layout with module_memorySong Liu2023-03-091-81/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | module_layout manages different types of memory (text, data, rodata, etc.) in one allocation, which is problematic for some reasons: 1. It is hard to enable CONFIG_STRICT_MODULE_RWX. 2. It is hard to use huge pages in modules (and not break strict rwx). 3. Many archs uses module_layout for arch-specific data, but it is not obvious how these data are used (are they RO, RX, or RW?) Improve the scenario by replacing 2 (or 3) module_layout per module with up to 7 module_memory per module: MOD_TEXT, MOD_DATA, MOD_RODATA, MOD_RO_AFTER_INIT, MOD_INIT_TEXT, MOD_INIT_DATA, MOD_INIT_RODATA, and allocating them separately. This adds slightly more entries to mod_tree (from up to 3 entries per module, to up to 7 entries per module). However, this at most adds a small constant overhead to __module_address(), which is expected to be fast. Various archs use module_layout for different data. These data are put into different module_memory based on their location in module_layout. IOW, data that used to go with text is allocated with MOD_MEM_TYPE_TEXT; data that used to go with data is allocated with MOD_MEM_TYPE_DATA, etc. module_memory simplifies quite some of the module code. For example, ARCH_WANTS_MODULES_DATA_IN_VMALLOC is a lot cleaner, as it just uses a different allocator for the data. kernel/module/strict_rwx.c is also much cleaner with module_memory. Signed-off-by: Song Liu <song@kernel.org> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
* module: Add CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOCChristophe Leroy2022-04-051-0/+1
| | | | | | | | | | | | | | | | | | | | | Add CONFIG_ARCH_WANTS_MODULES_DATA_IN_VMALLOC to allow architectures to request having modules data in vmalloc area instead of module area. This is required on powerpc book3s/32 in order to set data non executable, because it is not possible to set executability on page basis, this is done per 256 Mbytes segments. The module area has exec right, vmalloc area has noexec. This can also be useful on other powerpc/32 in order to maximize the chance of code being close enough to kernel core to avoid branch trampolines. Cc: Jason Wessel <jason.wessel@windriver.com> Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Cc: Douglas Anderson <dianders@chromium.org> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> [mcgrof: rebased in light of kernel/module/kdb.c move] Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
* module: Introduce data_layoutChristophe Leroy2022-04-051-5/+5
| | | | | | | | | | | | | | | In order to allow separation of data from text, add another layout, called data_layout. For architectures requesting separation of text and data, only text will go in core_layout and data will go in data_layout. For architectures which keep text and data together, make data_layout an alias of core_layout, that way data_layout can be used for all data manipulations, regardless of whether data is in core_layout or data_layout. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
* module: Rework layout alignment to avoid BUG_ON()sChristophe Leroy2022-04-051-9/+18
| | | | | | | | Perform layout alignment verification up front and WARN_ON() and fail module loading instead of crashing the machine. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
* module: Move module_enable_x() and frob_text() in strict_rwx.cChristophe Leroy2022-04-051-0/+48
| | | | | | | | | | | | | | | Move module_enable_x() together with module_enable_nx() and module_enable_ro(). Those three functions are going together, they are all used to set up the correct page flags on the different sections. As module_enable_x() is used independently of CONFIG_STRICT_MODULE_RWX, build strict_rwx.c all the time and use IS_ENABLED(CONFIG_STRICT_MODULE_RWX) when relevant. Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
* module: Move strict rwx support to a separate fileAaron Tomlin2022-04-051-0/+85
No functional change. This patch migrates code that makes module text and rodata memory read-only and non-text memory non-executable from core module code into kernel/module/strict_rwx.c. Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: Aaron Tomlin <atomlin@redhat.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>