From f0db674c643f8db29534b90ea9343e4dbddc2aac Mon Sep 17 00:00:00 2001 From: Ian Jackson Date: Thu, 28 Jun 2012 18:43:19 +0100 Subject: [PATCH] libxc: Do not segfault if (e.g.) switch_qemu_logdirty fails 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 Acked-by: Ian Campbell Committed-by: Ian Jackson --- tools/libxc/xc_domain_save.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/libxc/xc_domain_save.c b/tools/libxc/xc_domain_save.c index fcc7718ecb..c359649edb 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; } -- 2.30.2