From: Eric W. Biederman <ebiederm@xmission.com>
Date: Tue, 1 Aug 2017 10:02:38 +0000 (-0500)
Subject: mn10300/misalignment: Use SIGSEGV SEGV_MAPERR to report a failed user copy
X-Git-Tag: v3.2.102~107
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2aa8dcc6c0fed640aac249e2edac2013b797cc1c;p=thirdparty%2Fkernel%2Fstable.git

mn10300/misalignment: Use SIGSEGV SEGV_MAPERR to report a failed user copy

commit 6ac1dc736b323011a55ecd1fc5897c24c4f77cbd upstream.

Setting si_code to 0 is the same a setting si_code to SI_USER which is definitely
not correct.  With si_code set to SI_USER si_pid and si_uid will be copied to
userspace instead of si_addr.  Which is very wrong.

So fix this by using a sensible si_code (SEGV_MAPERR) for this failure.

Fixes: b920de1b77b7 ("mn10300: add the MN10300/AM33 architecture to the kernel")
Cc: David Howells <dhowells@redhat.com>
Cc: Masakazu Urade <urade.masakazu@jp.panasonic.com>
Cc: Koichi Yasutake <yasutake.koichi@jp.panasonic.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---

diff --git a/arch/mn10300/mm/misalignment.c b/arch/mn10300/mm/misalignment.c
index f9bb8cb1c14ad..c91d8add40c0d 100644
--- a/arch/mn10300/mm/misalignment.c
+++ b/arch/mn10300/mm/misalignment.c
@@ -438,7 +438,7 @@ transfer_failed:
 
 	info.si_signo	= SIGSEGV;
 	info.si_errno	= 0;
-	info.si_code	= 0;
+	info.si_code	= SEGV_MAPERR;
 	info.si_addr	= (void *) regs->pc;
 	force_sig_info(SIGSEGV, &info, current);
 	return;