diff options
| -rw-r--r-- | drivers/tty/serial/8250/8250_core.c | 2 | ||||
| -rw-r--r-- | include/linux/moduleparam.h | 44 | ||||
| -rw-r--r-- | kernel/params.c | 11 |
3 files changed, 47 insertions, 10 deletions
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index 1d42dba..bd67294 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -3587,7 +3587,7 @@ static void __used s8250_options(void) #ifdef CONFIG_SERIAL_8250_RSA __module_param_call(MODULE_PARAM_PREFIX, probe_rsa, ¶m_array_ops, .arr = &__param_arr_probe_rsa, - 0444, -1); + 0444, -1, 0); #endif } #else diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h index 16fddda..1e3ffb8 100644 --- a/include/linux/moduleparam.h +++ b/include/linux/moduleparam.h @@ -56,11 +56,21 @@ struct kernel_param_ops { void (*free)(void *arg); }; +/* + * Flags available for kernel_param + * + * UNSAFE - the parameter is dangerous and setting it will taint the kernel + */ +enum { + KERNEL_PARAM_FL_UNSAFE = (1 << 0) +}; + struct kernel_param { const char *name; const struct kernel_param_ops *ops; u16 perm; - s16 level; + s8 level; + u8 flags; union { void *arg; const struct kparam_string *str; @@ -137,7 +147,7 @@ struct kparam_array * The ops can have NULL set or get functions. */ #define module_param_cb(name, ops, arg, perm) \ - __module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, -1) + __module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, -1, 0) /** * <level>_param_cb - general callback for a module/cmdline parameter @@ -149,7 +159,7 @@ struct kparam_array * The ops can have NULL set or get functions. */ #define __level_param_cb(name, ops, arg, perm, level) \ - __module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, level) + __module_param_call(MODULE_PARAM_PREFIX, name, ops, arg, perm, level, 0) #define core_param_cb(name, ops, arg, perm) \ __level_param_cb(name, ops, arg, perm, 1) @@ -184,14 +194,14 @@ struct kparam_array /* This is the fundamental function for registering boot/module parameters. */ -#define __module_param_call(prefix, name, ops, arg, perm, level) \ +#define __module_param_call(prefix, name, ops, arg, perm, level, flags) \ /* Default value instead of permissions? */ \ static const char __param_str_##name[] = prefix #name; \ static struct kernel_param __moduleparam_const __param_##name \ __used \ __attribute__ ((unused,__section__ ("__param"),aligned(sizeof(void *)))) \ = { __param_str_##name, ops, VERIFY_OCTAL_PERMISSIONS(perm), \ - level, { arg } } + level, flags, { arg } } /* Obsolete - use module_param_cb() */ #define module_param_call(name, set, get, arg, perm) \ @@ -199,7 +209,7 @@ struct kparam_array { 0, (void *)set, (void *)get }; \ __module_param_call(MODULE_PARAM_PREFIX, \ name, &__param_ops_##name, arg, \ - (perm) + sizeof(__check_old_set_param(set))*0, -1) + (perm) + sizeof(__check_old_set_param(set))*0, -1, 0) /* We don't get oldget: it's often a new-style param_get_uint, etc. */ static inline int @@ -279,7 +289,7 @@ static inline void __kernel_param_unlock(void) */ #define core_param(name, var, type, perm) \ param_check_##type(name, &(var)); \ - __module_param_call("", name, ¶m_ops_##type, &var, perm, -1) + __module_param_call("", name, ¶m_ops_##type, &var, perm, -1, 0) #endif /* !MODULE */ /** @@ -297,7 +307,7 @@ static inline void __kernel_param_unlock(void) = { len, string }; \ __module_param_call(MODULE_PARAM_PREFIX, name, \ ¶m_ops_string, \ - .str = &__param_string_##name, perm, -1); \ + .str = &__param_string_##name, perm, -1, 0);\ __MODULE_PARM_TYPE(name, "string") /** @@ -346,6 +356,22 @@ static inline void destroy_params(const struct kernel_param *params, #define __param_check(name, p, type) \ static inline type __always_unused *__check_##name(void) { return(p); } +/** + * param_check_unsafe - Warn and taint the kernel if setting dangerous options. + * + * This gets called from all the standard param setters, but can be used from + * custom setters as well. + */ +static inline void +param_check_unsafe(const struct kernel_param *kp) +{ + if (kp->flags & KERNEL_PARAM_FL_UNSAFE) { + pr_warn("Setting dangerous option %s - tainting kernel\n", + kp->name); + add_taint(TAINT_USER, LOCKDEP_STILL_OK); + } +} + extern struct kernel_param_ops param_ops_byte; extern int param_set_byte(const char *val, const struct kernel_param *kp); extern int param_get_byte(char *buffer, const struct kernel_param *kp); @@ -444,7 +470,7 @@ extern int param_set_bint(const char *val, const struct kernel_param *kp); __module_param_call(MODULE_PARAM_PREFIX, name, \ ¶m_array_ops, \ .arr = &__param_arr_##name, \ - perm, -1); \ + perm, -1, 0); \ __MODULE_PARM_TYPE(name, "array of " #type) extern struct kernel_param_ops param_array_ops; diff --git a/kernel/params.c b/kernel/params.c index 8a484fc..ad8d045 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -233,6 +233,7 @@ char *parse_args(const char *doing, #define STANDARD_PARAM_DEF(name, type, format, strtolfn) \ int param_set_##name(const char *val, const struct kernel_param *kp) \ { \ + param_check_unsafe(kp); \ return strtolfn(val, 0, (type *)kp->arg); \ } \ int param_get_##name(char *buffer, const struct kernel_param *kp) \ @@ -265,6 +266,8 @@ int param_set_charp(const char *val, const struct kernel_param *kp) return -ENOSPC; } + param_check_unsafe(kp); + maybe_kfree_parameter(*(char **)kp->arg); /* This is a hack. We can't kmalloc in early boot, and we @@ -302,6 +305,8 @@ EXPORT_SYMBOL(param_ops_charp); /* Actually could be a bool or an int, for historical reasons. */ int param_set_bool(const char *val, const struct kernel_param *kp) { + param_check_unsafe(kp); + /* No equals means "set"... */ if (!val) val = "1"; @@ -331,6 +336,8 @@ int param_set_invbool(const char *val, const struct kernel_param *kp) bool boolval; struct kernel_param dummy; + param_check_unsafe(kp); + dummy.arg = &boolval; ret = param_set_bool(val, &dummy); if (ret == 0) @@ -357,6 +364,8 @@ int param_set_bint(const char *val, const struct kernel_param *kp) bool v; int ret; + param_check_unsafe(kp); + /* Match bool exactly, by re-using it. */ boolkp = *kp; boolkp.arg = &v; @@ -476,6 +485,8 @@ int param_set_copystring(const char *val, const struct kernel_param *kp) { const struct kparam_string *kps = kp->str; + param_check_unsafe(kp); + if (strlen(val)+1 > kps->maxlen) { pr_err("%s: string doesn't fit in %u chars.\n", kp->name, kps->maxlen-1); |
