From: Al Viro Date: Sat, 20 Aug 2016 20:36:36 +0000 (-0400) Subject: nios2: copy_from_user() should zero the tail of destination X-Git-Tag: firefly_0821_release~176^2~4^2~28^2~8 X-Git-Url: http://plrg.eecs.uci.edu/git/?p=firefly-linux-kernel-4.4.55.git;a=commitdiff_plain;h=ba5bfcba1f57eb99f6ef4fe91e2d1d9d8b9f4d50 nios2: copy_from_user() should zero the tail of destination commit e33d1f6f72cc82fcfc3d1fb20c9e3ad83b1928fa upstream. Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman --- diff --git a/arch/nios2/include/asm/uaccess.h b/arch/nios2/include/asm/uaccess.h index ebac5bbfc340..0ab82324c817 100644 --- a/arch/nios2/include/asm/uaccess.h +++ b/arch/nios2/include/asm/uaccess.h @@ -102,9 +102,12 @@ extern long __copy_to_user(void __user *to, const void *from, unsigned long n); static inline long copy_from_user(void *to, const void __user *from, unsigned long n) { - if (!access_ok(VERIFY_READ, from, n)) - return n; - return __copy_from_user(to, from, n); + unsigned long res = n; + if (access_ok(VERIFY_READ, from, n)) + res = __copy_from_user(to, from, n); + if (unlikely(res)) + memset(to + (n - res), 0, res); + return res; } static inline long copy_to_user(void __user *to, const void *from,