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| author | Alexey Dobriyan <adobriyan@gmail.com> | 2006-12-07 05:36:56 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@woody.osdl.org> | 2006-12-07 17:39:34 +0100 |
| commit | 9774a1f54f173ad18e816496c8979f1bf8ef666a (patch) | |
| tree | 43787344922cca18dfa0eba9a4fc3ce646e22bff | |
| parent | [PATCH] taskstats: cleanup reply assembling (diff) | |
| download | linux-9774a1f54f173ad18e816496c8979f1bf8ef666a.tar.xz linux-9774a1f54f173ad18e816496c8979f1bf8ef666a.zip | |
[PATCH] Compile-time check re world-writeable module params
One of the mistakes a module_param() user can make is to supply default
value of module parameter as the last argument. module_param() accepts
permissions instead. If default value is, say, 3 (-------wx), parameter
becomes world-writeable.
So far, the only remedy was to apply grep(1) and read drivers submitted
to -mm. BTDT.
With this patch applied, compiler will finally do some job.
*) bounds checking on permissions
*) world-writeable bit checking on permissions
*) compile breakage if checks trigger
First version of this check (only "& 2" part) directly caught 4 out of 7
places during my last grep.
Subject: Neverending module_param() bugs
[X] drivers/acpi/sbs.c:101:module_param(capacity_mode, int, CAPACITY_UNIT);
[X] drivers/acpi/sbs.c:102:module_param(update_mode, int, UPDATE_MODE);
[ ] drivers/acpi/sbs.c:103:module_param(update_info_mode, int, UPDATE_INFO_MODE);
[ ] drivers/acpi/sbs.c:104:module_param(update_time, int, UPDATE_TIME);
[ ] drivers/acpi/sbs.c:105:module_param(update_time2, int, UPDATE_TIME2);
[X] drivers/char/watchdog/sbc8360.c:203:module_param(timeout, int, 27);
[X] drivers/media/video/tuner-simple.c:13:module_param(offset, int, 0666);
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | include/linux/moduleparam.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h index 7c0c2c198f1f..4a189dadb160 100644 --- a/include/linux/moduleparam.h +++ b/include/linux/moduleparam.h @@ -63,6 +63,9 @@ struct kparam_array not there, read bits mean it's readable, write bits mean it's writable. */ #define __module_param_call(prefix, name, set, get, arg, perm) \ + /* Default value instead of permissions? */ \ + static int __param_perm_check_##name __attribute__((unused)) = \ + BUILD_BUG_ON_ZERO((perm) < 0 || (perm) > 0777 || ((perm) & 2)); \ static char __param_str_##name[] = prefix #name; \ static struct kernel_param const __param_##name \ __attribute_used__ \ |