[libvirt] [PATCHv2 2/4] fdstream: avoid double close bug
Wen Congyang reported that we have a double-close bug if we fail
virFDStreamOpenInternal, since childfd duplicated one of the fds[]
array contents. In truth, since we always transfer both members
of fds to other variables, we should close the fds through those
other names, and just use fds[] for pipe().
Bug present since 0.9.0 (commit e886237a).
* src/fdstream.c (virFDStreamOpenFileInternal): Swap scope of
childfd and fds[], to avoid a double close.
---
v2: my alternative to Wen's original proposal
src/fdstream.c | 7 +++----
1 files changed, 3 insertions(+), 4 deletions(-)
diff --git a/src/fdstream.c b/src/fdstream.c
index fca0f41..a4b41c0 100644
--- a/src/fdstream.c
+++ b/src/fdstream.c
@@ -577,7 +577,7 @@ virFDStreamOpenFileInternal(virStreamPtr st,
int mode)
{
int fd = -1;
- int fds[2] = { -1, -1 };
+ int childfd = -1;
struct stat sb;
virCommandPtr cmd = NULL;
int errfd = -1;
@@ -619,7 +619,7 @@ virFDStreamOpenFileInternal(virStreamPtr st,
if ((st->flags & VIR_STREAM_NONBLOCK) &&
(!S_ISCHR(sb.st_mode) &&
!S_ISFIFO(sb.st_mode))) {
- int childfd;
+ int fds[2] = { -1, -1 };
if ((oflags & O_ACCMODE) == O_RDWR) {
streamsReportError(VIR_ERR_INTERNAL_ERROR,
@@ -665,9 +665,8 @@ virFDStreamOpenFileInternal(virStreamPtr st,
error:
virCommandFree(cmd);
- VIR_FORCE_CLOSE(fds[0]);
- VIR_FORCE_CLOSE(fds[1]);
VIR_FORCE_CLOSE(fd);
+ VIR_FORCE_CLOSE(childfd);
VIR_FORCE_CLOSE(errfd);
if (oflags & O_CREAT)
unlink(path);
--
1.7.7.6