From 7a3d9b0f3abbea957b829cdfff8169872c575642 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Mon, 21 Oct 2013 09:44:37 +0100 Subject: x86: Unify copy_to_user() and add size checking to it Similarly to copy_from_user(), where the range check is to protect against kernel memory corruption, copy_to_user() can benefit from such checking too: Here it protects against kernel information leaks. Signed-off-by: Jan Beulich Cc: Cc: Linus Torvalds Cc: Andrew Morton Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/5265059502000078000FC4F6@nat28.tlf.novell.com Signed-off-by: Ingo Molnar Cc: Arjan van de Ven --- arch/x86/lib/usercopy_32.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'arch/x86/lib') diff --git a/arch/x86/lib/usercopy_32.c b/arch/x86/lib/usercopy_32.c index c408d0222917..e2f5e21c03b3 100644 --- a/arch/x86/lib/usercopy_32.c +++ b/arch/x86/lib/usercopy_32.c @@ -654,14 +654,13 @@ EXPORT_SYMBOL(__copy_from_user_ll_nocache_nozero); * Returns number of bytes that could not be copied. * On success, this will be zero. */ -unsigned long -copy_to_user(void __user *to, const void *from, unsigned long n) +unsigned long _copy_to_user(void __user *to, const void *from, unsigned n) { if (access_ok(VERIFY_WRITE, to, n)) n = __copy_to_user(to, from, n); return n; } -EXPORT_SYMBOL(copy_to_user); +EXPORT_SYMBOL(_copy_to_user); /** * copy_from_user: - Copy a block of data from user space. -- cgit