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From: Juergen Gross <jgross@suse.com>
To: xen-devel@lists.xenproject.org
Cc: Henry.Wang@arm.com, Juergen Gross <jgross@suse.com>,
	Andrew Cooper <andrew.cooper3@citrix.com>,
	George Dunlap <george.dunlap@citrix.com>,
	Jan Beulich <jbeulich@suse.com>, Julien Grall <julien@xen.org>,
	Stefano Stabellini <sstabellini@kernel.org>, Wei Liu <wl@xen.org>
Subject: [PATCH v2] xen/gnttab: fix gnttab_acquire_resource()
Date: Fri,  9 Sep 2022 12:24:13 +0200	[thread overview]
Message-ID: <20220909102413.2899-1-jgross@suse.com> (raw)

Commit 9dc46386d89d ("gnttab: work around "may be used uninitialized"
warning") was wrong, as vaddrs can legitimately be NULL in case
XENMEM_resource_grant_table_id_status was specified for a grant table
v1. This would result in crashes in debug builds due to
ASSERT_UNREACHABLE() triggering.

Check vaddrs only to be NULL in the rc == 0 case.

Fixes: 9dc46386d89d ("gnttab: work around "may be used uninitialized" warning")
Signed-off-by: Juergen Gross <jgross@suse.com>
Release-acked-by: Henry Wang <Henry.Wang@arm.com>
---
Might be considered for backporting
---
 xen/common/grant_table.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/common/grant_table.c b/xen/common/grant_table.c
index ad773a6996..fba329dcc2 100644
--- a/xen/common/grant_table.c
+++ b/xen/common/grant_table.c
@@ -4140,7 +4140,7 @@ int gnttab_acquire_resource(
      * on non-error paths, and hence it needs setting to NULL at the top of the
      * function.  Leave some runtime safety.
      */
-    if ( !vaddrs )
+    if ( !rc && !vaddrs )
     {
         ASSERT_UNREACHABLE();
         rc = -ENODATA;
-- 
2.35.3



             reply	other threads:[~2022-09-09 10:24 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-09-09 10:24 Juergen Gross [this message]
2022-09-09 10:34 ` [PATCH v2] xen/gnttab: fix gnttab_acquire_resource() Jan Beulich
2022-09-09 10:46 ` Andrew Cooper

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