Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753372AbcKNDER (ORCPT ); Sun, 13 Nov 2016 22:04:17 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:46343 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753138AbcKNCF7 (ORCPT ); Sun, 13 Nov 2016 21:05:59 -0500 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Jesper Nilsson" , "Al Viro" Date: Mon, 14 Nov 2016 00:14:07 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.2 107/152] cris: buggered copy_from_user/copy_to_user/clear_user In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3764 Lines: 130 3.2.84-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Al Viro commit eb47e0293baaa3044022059f1fa9ff474bfe35cb upstream. * copy_from_user() on access_ok() failure ought to zero the destination * none of those primitives should skip the access_ok() check in case of small constant size. Acked-by: Jesper Nilsson Signed-off-by: Al Viro [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings --- arch/cris/include/asm/uaccess.h | 71 +++++++++++++++++++---------------------- 1 file changed, 32 insertions(+), 39 deletions(-) --- a/arch/cris/include/asm/uaccess.h +++ b/arch/cris/include/asm/uaccess.h @@ -176,30 +176,6 @@ extern unsigned long __copy_user(void __ extern unsigned long __copy_user_zeroing(void *to, const void __user *from, unsigned long n); extern unsigned long __do_clear_user(void __user *to, unsigned long n); -static inline unsigned long -__generic_copy_to_user(void __user *to, const void *from, unsigned long n) -{ - if (access_ok(VERIFY_WRITE, to, n)) - return __copy_user(to,from,n); - return n; -} - -static inline unsigned long -__generic_copy_from_user(void *to, const void __user *from, unsigned long n) -{ - if (access_ok(VERIFY_READ, from, n)) - return __copy_user_zeroing(to,from,n); - return n; -} - -static inline unsigned long -__generic_clear_user(void __user *to, unsigned long n) -{ - if (access_ok(VERIFY_WRITE, to, n)) - return __do_clear_user(to,n); - return n; -} - static inline long __strncpy_from_user(char *dst, const char __user *src, long count) { @@ -262,7 +238,7 @@ __constant_copy_from_user(void *to, cons else if (n == 24) __asm_copy_from_user_24(to, from, ret); else - ret = __generic_copy_from_user(to, from, n); + ret = __copy_user_zeroing(to, from, n); return ret; } @@ -312,7 +288,7 @@ __constant_copy_to_user(void __user *to, else if (n == 24) __asm_copy_to_user_24(to, from, ret); else - ret = __generic_copy_to_user(to, from, n); + ret = __copy_user(to, from, n); return ret; } @@ -344,26 +320,43 @@ __constant_clear_user(void __user *to, u else if (n == 24) __asm_clear_24(to, ret); else - ret = __generic_clear_user(to, n); + ret = __do_clear_user(to, n); return ret; } -#define clear_user(to, n) \ -(__builtin_constant_p(n) ? \ - __constant_clear_user(to, n) : \ - __generic_clear_user(to, n)) - -#define copy_from_user(to, from, n) \ -(__builtin_constant_p(n) ? \ - __constant_copy_from_user(to, from, n) : \ - __generic_copy_from_user(to, from, n)) - -#define copy_to_user(to, from, n) \ -(__builtin_constant_p(n) ? \ - __constant_copy_to_user(to, from, n) : \ - __generic_copy_to_user(to, from, n)) +static inline size_t clear_user(void __user *to, size_t n) +{ + if (unlikely(!access_ok(VERIFY_WRITE, to, n))) + return n; + if (__builtin_constant_p(n)) + return __constant_clear_user(to, n); + else + return __do_clear_user(to, n); +} + +static inline size_t copy_from_user(void *to, const void __user *from, size_t n) +{ + if (unlikely(!access_ok(VERIFY_READ, from, n))) { + memset(to, 0, n); + return n; + } + if (__builtin_constant_p(n)) + return __constant_copy_from_user(to, from, n); + else + return __copy_user_zeroing(to, from, n); +} + +static inline size_t copy_to_user(void __user *to, const void *from, size_t n) +{ + if (unlikely(!access_ok(VERIFY_WRITE, to, n))) + return n; + if (__builtin_constant_p(n)) + return __constant_copy_to_user(to, from, n); + else + return __copy_user(to, from, n); +} /* We let the __ versions of copy_from/to_user inline, because they're often * used in fast paths and have only a small space overhead.