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| author | Rusty Russell <rusty@rustcorp.com.au> | 2008-10-22 10:00:22 -0500 |
|---|---|---|
| committer | Rusty Russell <rusty@rustcorp.com.au> | 2008-10-22 10:00:22 +1100 |
| commit | 730b69d225259565c705f5f5a11cb1aba69568f1 (patch) | |
| tree | 9ae3f20102d06d83b23dbbed1ae8acb86e01e7ea | |
| parent | d72b37513cdfbd3f53f3d485a8c403cc96d2c95f (diff) | |
| download | linux-730b69d225259565c705f5f5a11cb1aba69568f1.tar.gz linux-730b69d225259565c705f5f5a11cb1aba69568f1.tar.xz | |
module: check kernel param length at compile time, not runtime
The kparam code tries to handle over-length parameter prefixes at
runtime. Not only would I bet this has never been tested, it's not
clear that truncating names is a good idea either.
So let's check at compile time. We need to move the #define to
moduleparam.h to do this, though.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| -rw-r--r-- | include/linux/module.h | 2 | ||||
| -rw-r--r-- | include/linux/moduleparam.h | 6 | ||||
| -rw-r--r-- | kernel/params.c | 7 |
3 files changed, 8 insertions, 7 deletions
diff --git a/include/linux/module.h b/include/linux/module.h index eddf27db442b..196b499270da 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -29,7 +29,7 @@ #define MODULE_SYMBOL_PREFIX "" #endif -#define MODULE_NAME_LEN (64 - sizeof(unsigned long)) +#define MODULE_NAME_LEN MAX_PARAM_PREFIX_LEN struct kernel_symbol { diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h index ec624381c844..1eefe6d61b86 100644 --- a/include/linux/moduleparam.h +++ b/include/linux/moduleparam.h @@ -13,6 +13,9 @@ #define MODULE_PARAM_PREFIX KBUILD_MODNAME "." #endif +/* Chosen so that structs with an unsigned long line up. */ +#define MAX_PARAM_PREFIX_LEN (64 - sizeof(unsigned long)) + #ifdef MODULE #define ___module_cat(a,b) __mod_ ## a ## b #define __module_cat(a,b) ___module_cat(a,b) @@ -79,7 +82,8 @@ struct kparam_array #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)); \ + BUILD_BUG_ON_ZERO((perm) < 0 || (perm) > 0777 || ((perm) & 2)) \ + + BUILD_BUG_ON_ZERO(sizeof(""prefix) > MAX_PARAM_PREFIX_LEN); \ static const char __param_str_##name[] = prefix #name; \ static struct kernel_param __moduleparam_const __param_##name \ __used \ diff --git a/kernel/params.c b/kernel/params.c index afc46a23eb6d..aca07e1a050f 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -585,17 +585,14 @@ static void __init param_sysfs_builtin(void) { struct kernel_param *kp, *kp_begin = NULL; unsigned int i, name_len, count = 0; - char modname[MODULE_NAME_LEN + 1] = ""; + char modname[MODULE_NAME_LEN] = ""; for (i=0; i < __stop___param - __start___param; i++) { char *dot; - size_t max_name_len; kp = &__start___param[i]; - max_name_len = - min_t(size_t, MODULE_NAME_LEN, strlen(kp->name)); - dot = memchr(kp->name, '.', max_name_len); + dot = strchr(kp->name, '.'); if (!dot) { DEBUGP("couldn't find period in first %d characters " "of %s\n", MODULE_NAME_LEN, kp->name); |