The patch titled
x86: implement strict user copy checks for x86_64
has been added to the -mm tree. Its filename is
x86-implement-strict-user-copy-checks-for-x86_64.patch
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Subject: x86: implement strict user copy checks for x86_64
From: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
Strict user copy checks are only really supported on x86_32 even though
the config option is selectable on x86_64. Add the necessary support to
the 64 bit code to trigger copy_from_user() warnings at compile time.
Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
Acked-by: Ingo Molnar <mingo@xxxxxxx>
Acked-by: H. Peter Anvin <hpa@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/x86/include/asm/uaccess_64.h | 12 +++++++++---
arch/x86/lib/usercopy_64.c | 6 ++++++
2 files changed, 15 insertions(+), 3 deletions(-)
diff -puN arch/x86/include/asm/uaccess_64.h~x86-implement-strict-user-copy-checks-for-x86_64 arch/x86/include/asm/uaccess_64.h
--- a/arch/x86/include/asm/uaccess_64.h~x86-implement-strict-user-copy-checks-for-x86_64
+++ a/arch/x86/include/asm/uaccess_64.h
@@ -43,6 +43,14 @@ _copy_from_user(void *to, const void __u
__must_check unsigned long
copy_in_user(void __user *to, const void __user *from, unsigned len);
+extern void copy_from_user_overflow(void)
+#ifdef CONFIG_DEBUG_STRICT_USER_COPY_CHECKS
+ __compiletime_error("copy_from_user() buffer size is not provably correct")
+#else
+ __compiletime_warning("copy_from_user() buffer size is not provably correct")
+#endif
+;
+
static inline unsigned long __must_check copy_from_user(void *to,
const void __user *from,
unsigned long n)
@@ -52,10 +60,8 @@ static inline unsigned long __must_check
might_fault();
if (likely(sz == -1 || sz >= n))
n = _copy_from_user(to, from, n);
-#ifdef CONFIG_DEBUG_VM
else
- WARN(1, "Buffer overflow detected!\n");
-#endif
+ copy_from_user_overflow();
return n;
}
diff -puN arch/x86/lib/usercopy_64.c~x86-implement-strict-user-copy-checks-for-x86_64 arch/x86/lib/usercopy_64.c
--- a/arch/x86/lib/usercopy_64.c~x86-implement-strict-user-copy-checks-for-x86_64
+++ a/arch/x86/lib/usercopy_64.c
@@ -181,3 +181,9 @@ copy_user_handle_tail(char *to, char *fr
break;
return len;
}
+
+void copy_from_user_overflow(void)
+{
+ WARN(1, "Buffer overflow detected!\n");
+}
+EXPORT_SYMBOL(copy_from_user_overflow);
_
Patches currently in -mm which might be from sboyd@xxxxxxxxxxxxxx are
linux-next.patch
lpfc-silence-debug_strict_user_copy_checks=y-warning.patch
kprobes-silence-debug_strict_user_copy_checks=y-warning.patch
x86-implement-strict-user-copy-checks-for-x86_64.patch
consolidate-config_debug_strict_user_copy_checks.patch
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