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From: Jan Beulich <jbeulich@suse.com>
To: "xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>
Cc: Christopher Clark <christopher.w.clark@gmail.com>
Subject: [PATCH] argo: don't leak stack contents when returning ring info
Date: Thu, 14 Jan 2021 15:01:06 +0100	[thread overview]
Message-ID: <a2621d1e-dd52-4e46-9e4b-dffd94e73993@suse.com> (raw)

The max_message_size field of the output gets filled only when the flags
field is non-zero. Don't copy back uninitialized data to guest context.

Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/xen/common/argo.c
+++ b/xen/common/argo.c
@@ -1405,7 +1405,8 @@ fill_ring_data(const struct domain *curr
         rcu_unlock_domain(dst_d);
 
     if ( !ret && (__copy_field_to_guest(data_ent_hnd, &ent, flags) ||
-                  __copy_field_to_guest(data_ent_hnd, &ent, max_message_size)) )
+                  (ent.flags &&
+                   __copy_field_to_guest(data_ent_hnd, &ent, max_message_size))) )
         return -EFAULT;
 
     return ret;


             reply	other threads:[~2021-01-14 14:01 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-14 14:01 Jan Beulich [this message]
2021-01-14 16:59 ` [PATCH] argo: don't leak stack contents when returning ring info Roger Pau Monné
2021-01-14 17:01   ` Jan Beulich

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