From: Jan Beulich <jbeulich@suse.com>
Date: Mon, 15 Feb 2021 07:50:08 +0000 (+0100)
Subject: Xen/x86: also check kernel mapping in set_foreign_p2m_mapping()
X-Git-Tag: v4.4.258~10
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2e915736abc8478f754ed6b591af0d4d1385dd8b;p=thirdparty%2Fkernel%2Fstable.git

Xen/x86: also check kernel mapping in set_foreign_p2m_mapping()

commit b512e1b077e5ccdbd6e225b15d934ab12453b70a upstream.

We should not set up further state if either mapping failed; paying
attention to just the user mapping's status isn't enough.

Also use GNTST_okay instead of implying its value (zero).

This is part of XSA-361.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: stable@vger.kernel.org
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index a28552841949f..8c7c5bb94257e 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -725,7 +725,8 @@ int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
 		unsigned long mfn, pfn;
 
 		/* Do not add to override if the map failed. */
-		if (map_ops[i].status)
+		if (map_ops[i].status != GNTST_okay ||
+		    (kmap_ops && kmap_ops[i].status != GNTST_okay))
 			continue;
 
 		if (map_ops[i].flags & GNTMAP_contains_pte) {