From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ian Jackson Subject: [PATCH 02/21] libxc: Do not segfault if (e.g.) switch_qemu_logdirty fails Date: Fri, 15 Jun 2012 12:53:47 +0100 Message-ID: <1339761246-27641-3-git-send-email-ian.jackson@eu.citrix.com> References: <1339761246-27641-1-git-send-email-ian.jackson@eu.citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1339761246-27641-1-git-send-email-ian.jackson@eu.citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: xen-devel@lists.xen.org Cc: Ian Jackson List-Id: xen-devel@lists.xenproject.org In xc_domain_save the local variable `ob' is initialised to NULL. There are then various startup actions. Some of these `goto out' on failure; for example the call to callbacks->switch_qemu_logdirty on l.978. However, out is used both by success and error paths. So it attempts (l.2043) to flush the current output buffer. If ob has not yet been assigned a non-NULL value, this segfaults. So make the call to outbuf_flush conditional on ob. Signed-off-by: Ian Jackson --- tools/libxc/xc_domain_save.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/tools/libxc/xc_domain_save.c b/tools/libxc/xc_domain_save.c index fcc7718..c359649 100644 --- a/tools/libxc/xc_domain_save.c +++ b/tools/libxc/xc_domain_save.c @@ -2040,7 +2040,7 @@ int xc_domain_save(xc_interface *xch, int io_fd, uint32_t dom, uint32_t max_iter } /* Flush last write and discard cache for file. */ - if ( outbuf_flush(xch, ob, io_fd) < 0 ) { + if ( ob && outbuf_flush(xch, ob, io_fd) < 0 ) { PERROR("Error when flushing output buffer"); rc = 1; } -- 1.7.2.5