[PATCHv2] libxc: fix segfault on uninitialized xch->fmem

From: Seraphime Kirkovski <kirkseraph@gmail.com>
To: xen-devel@lists.xen.org
Cc: Ian Jackson <ian.jackson@eu.citrix.com>,
	Wei Liu <wei.liu2@citrix.com>,
	Seraphime Kirkovski <kirkseraph@gmail.com>
Subject: [PATCHv2] libxc: fix segfault on uninitialized xch->fmem
Date: Tue,  4 Apr 2017 14:40:48 +0200	[thread overview]
Message-ID: <20170404124048.9603-1-kirkseraph@gmail.com> (raw)

Currently in xc_interface_open, xch->fmem is not initialized
and in some rare case the code fails before ever assigning a value
to it.

I got this in master:

   $ sudo ./xl/xl run
   xencall: error: Could not obtain handle on privileged command interface: No such file or directory
   Segmentation fault

This initializes the whole xch_buff to 0.

Signed-off-by: Seraphime Kirkovski <kirkseraph@gmail.com>
---

 Changes from v1:
   * Initialize the entire struct xc_interface_core to 0

 tools/libxc/xc_private.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/libxc/xc_private.c b/tools/libxc/xc_private.c
index 72e6242417..f395594a8f 100644
--- a/tools/libxc/xc_private.c
+++ b/tools/libxc/xc_private.c
@@ -30,7 +30,7 @@ struct xc_interface_core *xc_interface_open(xentoollog_logger *logger,
                                             xentoollog_logger *dombuild_logger,
                                             unsigned open_flags)
 {
-    struct xc_interface_core xch_buf, *xch = &xch_buf;
+    struct xc_interface_core xch_buf = { 0 }, *xch = &xch_buf;
 
     xch->flags = open_flags;
     xch->dombuild_logger_file = 0;
-- 
2.11.0


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