[PATCH 01/14] x86/soft-reset: Drop gfn reference after calling get_gfn_query()

From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Xen-devel <xen-devel@lists.xen.org>
Cc: "Andrew Cooper" <andrew.cooper3@citrix.com>,
	"Wei Liu" <wei.liu2@citrix.com>,
	"Jan Beulich" <JBeulich@suse.com>,
	"Roger Pau Monné" <roger.pau@citrix.com>
Subject: [PATCH 01/14] x86/soft-reset: Drop gfn reference after calling get_gfn_query()
Date: Wed, 21 Nov 2018 13:21:09 +0000	[thread overview]
Message-ID: <1542806482-24030-2-git-send-email-andrew.cooper3@citrix.com> (raw)
In-Reply-To: <1542806482-24030-1-git-send-email-andrew.cooper3@citrix.com>

get_gfn_query() internally takes the p2m lock, and this error path leaves it
locked.

This wasn't included in XSA-277 because the error path can only be triggered
by a carefully timed phymap operation concurrent with the domain being paused
and the toolstack issuing DOMCTL_soft_reset.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
---
CC: Jan Beulich <JBeulich@suse.com>
CC: Wei Liu <wei.liu2@citrix.com>
CC: Roger Pau Monné <roger.pau@citrix.com>
---
 xen/arch/x86/domain.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index 295b10c..b4d5948 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -725,7 +725,7 @@ int arch_domain_soft_reset(struct domain *d)
         printk(XENLOG_G_ERR "Failed to get Dom%d's shared_info GFN (%lx)\n",
                d->domain_id, gfn);
         ret = -EINVAL;
-        goto exit_put_page;
+        goto exit_put_gfn;
     }
 
     new_page = alloc_domheap_page(d, 0);
-- 
2.1.4


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