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-rw-r--r--include/linux/thread_info.h27
-rw-r--r--include/linux/uaccess.h28
2 files changed, 29 insertions, 26 deletions
diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h
index d7d3ea637dd0..250a27614328 100644
--- a/include/linux/thread_info.h
+++ b/include/linux/thread_info.h
@@ -113,6 +113,33 @@ static inline void check_object_size(const void *ptr, unsigned long n,
{ }
#endif /* CONFIG_HARDENED_USERCOPY */
+extern void __compiletime_error("copy source size is too small")
+__bad_copy_from(void);
+extern void __compiletime_error("copy destination size is too small")
+__bad_copy_to(void);
+
+static inline void copy_overflow(int size, unsigned long count)
+{
+ WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
+}
+
+static __always_inline bool
+check_copy_size(const void *addr, size_t bytes, bool is_source)
+{
+ int sz = __compiletime_object_size(addr);
+ if (unlikely(sz >= 0 && sz < bytes)) {
+ if (!__builtin_constant_p(bytes))
+ copy_overflow(sz, bytes);
+ else if (is_source)
+ __bad_copy_from();
+ else
+ __bad_copy_to();
+ return false;
+ }
+ check_object_size(addr, bytes, is_source);
+ return true;
+}
+
#ifndef arch_setup_new_exec
static inline void arch_setup_new_exec(void) { }
#endif
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index e57328896a16..80b587085e79 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -139,43 +139,19 @@ extern unsigned long
_copy_to_user(void __user *, const void *, unsigned long);
#endif
-extern void __compiletime_error("usercopy buffer size is too small")
-__bad_copy_user(void);
-
-static inline void copy_user_overflow(int size, unsigned long count)
-{
- WARN(1, "Buffer overflow detected (%d < %lu)!\n", size, count);
-}
-
static __always_inline unsigned long __must_check
copy_from_user(void *to, const void __user *from, unsigned long n)
{
- int sz = __compiletime_object_size(to);
-
- if (likely(sz < 0 || sz >= n)) {
- check_object_size(to, n, false);
+ if (likely(check_copy_size(to, n, false)))
n = _copy_from_user(to, from, n);
- } else if (!__builtin_constant_p(n))
- copy_user_overflow(sz, n);
- else
- __bad_copy_user();
-
return n;
}
static __always_inline unsigned long __must_check
copy_to_user(void __user *to, const void *from, unsigned long n)
{
- int sz = __compiletime_object_size(from);
-
- if (likely(sz < 0 || sz >= n)) {
- check_object_size(from, n, true);
+ if (likely(check_copy_size(from, n, true)))
n = _copy_to_user(to, from, n);
- } else if (!__builtin_constant_p(n))
- copy_user_overflow(sz, n);
- else
- __bad_copy_user();
-
return n;
}
#ifdef CONFIG_COMPAT