From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Al Viro Subject: [PATCH 4.7 180/184] ppc32: fix copy_from_user() Date: Thu, 22 Sep 2016 19:41:54 +0200 Message-Id: <20160922174056.392028259@linuxfoundation.org> In-Reply-To: <20160922174048.653794923@linuxfoundation.org> References: <20160922174048.653794923@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.7-stable review patch. If anyone has any objections, please let me know. ------------------ From: Al Viro commit 224264657b8b228f949b42346e09ed8c90136a8e upstream. should clear on access_ok() failures. Also remove the useless range truncation logics. Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/include/asm/uaccess.h | 21 ++------------------- 1 file changed, 2 insertions(+), 19 deletions(-) --- a/arch/powerpc/include/asm/uaccess.h +++ b/arch/powerpc/include/asm/uaccess.h @@ -308,30 +308,17 @@ extern unsigned long __copy_tofrom_user( static inline unsigned long copy_from_user(void *to, const void __user *from, unsigned long n) { - unsigned long over; - - if (access_ok(VERIFY_READ, from, n)) + if (likely(access_ok(VERIFY_READ, from, n))) return __copy_tofrom_user((__force void __user *)to, from, n); - if ((unsigned long)from < TASK_SIZE) { - over = (unsigned long)from + n - TASK_SIZE; - return __copy_tofrom_user((__force void __user *)to, from, - n - over) + over; - } ++ memset(to, 0, n); return n; } static inline unsigned long copy_to_user(void __user *to, const void *from, unsigned long n) { - unsigned long over; - if (access_ok(VERIFY_WRITE, to, n)) return __copy_tofrom_user(to, (__force void __user *)from, n); - if ((unsigned long)to < TASK_SIZE) { - over = (unsigned long)to + n - TASK_SIZE; - return __copy_tofrom_user(to, (__force void __user *)from, - n - over) + over; - } return n; } @@ -422,10 +409,6 @@ static inline unsigned long clear_user(v might_fault(); if (likely(access_ok(VERIFY_WRITE, addr, size))) return __clear_user(addr, size); - if ((unsigned long)addr < TASK_SIZE) { - unsigned long over = (unsigned long)addr + size - TASK_SIZE; - return __clear_user(addr, size - over) + over; - } return size; }