[patch added to 3.12-stable] alpha: fix copy_from_user()
From: Jiri Slaby <hidden>
Date: 2016-09-29 09:07:11
Subsystem:
alpha port, the rest · Maintainers:
Richard Henderson, Matt Turner, Magnus Lindholm, Linus Torvalds
From: Al Viro <viro@zeniv.linux.org.uk> This patch has been added to the 3.12 stable tree. If you have any objections, please let us know. =============== commit 2561d309dfd1555e781484af757ed0115035ddb3 upstream. it should clear the destination even when access_ok() fails. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Jiri Slaby <redacted> --- arch/alpha/include/asm/uaccess.h | 19 ++++++++----------- 1 file changed, 8 insertions(+), 11 deletions(-)
diff --git a/arch/alpha/include/asm/uaccess.h b/arch/alpha/include/asm/uaccess.h
index 766fdfde2b7a..6e9d27ad5103 100644
--- a/arch/alpha/include/asm/uaccess.h
+++ b/arch/alpha/include/asm/uaccess.h@@ -371,14 +371,6 @@ __copy_tofrom_user_nocheck(void *to, const void *from, long len) return __cu_len; } -extern inline long -__copy_tofrom_user(void *to, const void *from, long len, const void __user *validate) -{ - if (__access_ok((unsigned long)validate, len, get_fs())) - len = __copy_tofrom_user_nocheck(to, from, len); - return len; -} - #define __copy_to_user(to,from,n) \ ({ \ __chk_user_ptr(to); \
@@ -393,17 +385,22 @@ __copy_tofrom_user(void *to, const void *from, long len, const void __user *vali #define __copy_to_user_inatomic __copy_to_user #define __copy_from_user_inatomic __copy_from_user - extern inline long copy_to_user(void __user *to, const void *from, long n) { - return __copy_tofrom_user((__force void *)to, from, n, to); + if (likely(__access_ok((unsigned long)to, n, get_fs()))) + n = __copy_tofrom_user_nocheck((__force void *)to, from, n); + return n; } extern inline long copy_from_user(void *to, const void __user *from, long n) { - return __copy_tofrom_user(to, (__force void *)from, n, from); + if (likely(__access_ok((unsigned long)from, n, get_fs()))) + n = __copy_tofrom_user_nocheck(to, (__force void *)from, n); + else + memset(to, 0, n); + return n; } extern void __do_clear_user(void);
--
2.10.0