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-rw-r--r--arch/x86/include/asm/uaccess_32.h19
-rw-r--r--arch/x86/include/asm/uaccess_64.h19
-rw-r--r--arch/x86/kernel/x8664_ksyms_64.c2
-rw-r--r--arch/x86/lib/copy_user_64.S4
-rw-r--r--arch/x86/lib/usercopy_32.c4
-rw-r--r--include/linux/compiler-gcc4.h2
-rw-r--r--include/linux/compiler.h4
7 files changed, 47 insertions, 7 deletions
diff --git a/arch/x86/include/asm/uaccess_32.h b/arch/x86/include/asm/uaccess_32.h
index 632fb44..582d6ae 100644
--- a/arch/x86/include/asm/uaccess_32.h
+++ b/arch/x86/include/asm/uaccess_32.h
@@ -187,9 +187,26 @@ __copy_from_user_inatomic_nocache(void *to, const void __user *from,
unsigned long __must_check copy_to_user(void __user *to,
const void *from, unsigned long n);
-unsigned long __must_check copy_from_user(void *to,
+unsigned long __must_check _copy_from_user(void *to,
const void __user *from,
unsigned long n);
+
+static inline unsigned long __must_check copy_from_user(void *to,
+ const void __user *from,
+ unsigned long n)
+{
+ int sz = __compiletime_object_size(to);
+ int ret = -EFAULT;
+
+ if (likely(sz == -1 || sz >= n))
+ ret = _copy_from_user(to, from, n);
+#ifdef CONFIG_DEBUG_VM
+ else
+ WARN(1, "Buffer overflow detected!\n");
+#endif
+ return ret;
+}
+
long __must_check strncpy_from_user(char *dst, const char __user *src,
long count);
long __must_check __strncpy_from_user(char *dst,
diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h
index db24b21..ce6fec7 100644
--- a/arch/x86/include/asm/uaccess_64.h
+++ b/arch/x86/include/asm/uaccess_64.h
@@ -21,10 +21,27 @@ copy_user_generic(void *to, const void *from, unsigned len);
__must_check unsigned long
copy_to_user(void __user *to, const void *from, unsigned len);
__must_check unsigned long
-copy_from_user(void *to, const void __user *from, unsigned len);
+_copy_from_user(void *to, const void __user *from, unsigned len);
__must_check unsigned long
copy_in_user(void __user *to, const void __user *from, unsigned len);
+static inline unsigned long __must_check copy_from_user(void *to,
+ const void __user *from,
+ unsigned long n)
+{
+ int sz = __compiletime_object_size(to);
+ int ret = -EFAULT;
+
+ if (likely(sz == -1 || sz >= n))
+ ret = _copy_from_user(to, from, n);
+#ifdef CONFIG_DEBUG_VM
+ else
+ WARN(1, "Buffer overflow detected!\n");
+#endif
+ return ret;
+}
+
+
static __always_inline __must_check
int __copy_from_user(void *dst, const void __user *src, unsigned size)
{
diff --git a/arch/x86/kernel/x8664_ksyms_64.c b/arch/x86/kernel/x8664_ksyms_64.c
index 3909e3b..a0cdd8c 100644
--- a/arch/x86/kernel/x8664_ksyms_64.c
+++ b/arch/x86/kernel/x8664_ksyms_64.c
@@ -30,7 +30,7 @@ EXPORT_SYMBOL(__put_user_8);
EXPORT_SYMBOL(copy_user_generic);
EXPORT_SYMBOL(__copy_user_nocache);
-EXPORT_SYMBOL(copy_from_user);
+EXPORT_SYMBOL(_copy_from_user);
EXPORT_SYMBOL(copy_to_user);
EXPORT_SYMBOL(__copy_from_user_inatomic);
diff --git a/arch/x86/lib/copy_user_64.S b/arch/x86/lib/copy_user_64.S
index 6ba0f7b..4be3c41 100644
--- a/arch/x86/lib/copy_user_64.S
+++ b/arch/x86/lib/copy_user_64.S
@@ -78,7 +78,7 @@ ENTRY(copy_to_user)
ENDPROC(copy_to_user)
/* Standard copy_from_user with segment limit checking */
-ENTRY(copy_from_user)
+ENTRY(_copy_from_user)
CFI_STARTPROC
GET_THREAD_INFO(%rax)
movq %rsi,%rcx
@@ -88,7 +88,7 @@ ENTRY(copy_from_user)
jae bad_from_user
ALTERNATIVE_JUMP X86_FEATURE_REP_GOOD,copy_user_generic_unrolled,copy_user_generic_string
CFI_ENDPROC
-ENDPROC(copy_from_user)
+ENDPROC(_copy_from_user)
ENTRY(copy_user_generic)
CFI_STARTPROC
diff --git a/arch/x86/lib/usercopy_32.c b/arch/x86/lib/usercopy_32.c
index 1f118d4..8498684 100644
--- a/arch/x86/lib/usercopy_32.c
+++ b/arch/x86/lib/usercopy_32.c
@@ -874,7 +874,7 @@ EXPORT_SYMBOL(copy_to_user);
* data to the requested size using zero bytes.
*/
unsigned long
-copy_from_user(void *to, const void __user *from, unsigned long n)
+_copy_from_user(void *to, const void __user *from, unsigned long n)
{
if (access_ok(VERIFY_READ, from, n))
n = __copy_from_user(to, from, n);
@@ -882,4 +882,4 @@ copy_from_user(void *to, const void __user *from, unsigned long n)
memset(to, 0, n);
return n;
}
-EXPORT_SYMBOL(copy_from_user);
+EXPORT_SYMBOL(_copy_from_user);
diff --git a/include/linux/compiler-gcc4.h b/include/linux/compiler-gcc4.h
index 450fa59..a3aef5d 100644
--- a/include/linux/compiler-gcc4.h
+++ b/include/linux/compiler-gcc4.h
@@ -37,3 +37,5 @@
#define __cold __attribute__((__cold__))
#endif
+
+#define __compiletime_object_size(obj) __builtin_object_size(obj, 0)
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 04fb513..8e54108 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -266,6 +266,10 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
# define __same_type(a, b) __builtin_types_compatible_p(typeof(a), typeof(b))
#endif
+/* Compile time object size, -1 for unknown */
+#ifndef __compiletime_object_size
+# define __compiletime_object_size(obj) -1
+#endif
/*
* Prevent the compiler from merging or refetching accesses. The compiler
* is also forbidden from reordering successive instances of ACCESS_ONCE(),
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