[libvirt] PATCH: better error checking for LOCAL_PEERCRED
I was debugging libvirt with OSX today, and got as far as finding the
problem with LOCAL_PEERCRED, then googled this only to find that Ryota
Ozaki had fixed the problems a few days ago!
However you still may find the following patch useful. It tightens up
the checking in the LOCAL_PEERCRED block, and in particular fixes the
unlocking of the socket in the error return path for invalid groups, by
using the same logic from SO_PEERCRED - have a 'goto cleanup' in all
return paths.
(Detail: I found that when getsockopt was being called with SOL_SOCKET,
cr_ngroups was typically <0, probably because it was uninitialised.
However once the check for this was tightened, it hung because the
socket wasn't being unlocked on return. So better to (a) initialise it
to a negative value anyway, and (b) fix the return path)
However I have not checked that NGROUPS is defined on other BSD-like
systems. You could just have "if (cr.cr_ngroups <= 0)" instead.
Regards,
Brian Candler.
--- src/rpc/virnetsocket.c.orig 2013-10-10 22:37:49.000000000 +0100
+++ src/rpc/virnetsocket.c 2013-10-12 22:51:57.000000000 +0100
@@ -1157,8 +1157,10 @@
{
struct xucred cr;
socklen_t cr_len = sizeof(cr);
+ int ret = -1;
virObjectLock(sock);
+ cr.cr_ngroups = -1;
# if defined(__APPLE__)
if (getsockopt(sock->fd, SOL_LOCAL, LOCAL_PEERCRED, &cr, &cr_len)
< 0) {
# else
@@ -1166,20 +1168,19 @@
# endif
virReportSystemError(errno, "%s",
_("Failed to get client socket identity"));
- virObjectUnlock(sock);
- return -1;
+ goto cleanup;
}
if (cr.cr_version != XUCRED_VERSION) {
virReportError(VIR_ERR_SYSTEM_ERROR, "%s",
_("Failed to get valid client socket identity"));
- return -1;
+ goto cleanup;
}
- if (cr.cr_ngroups == 0) {
+ if (cr.cr_ngroups <= 0 || cr.cr_ngroups > NGROUPS) {
virReportError(VIR_ERR_SYSTEM_ERROR, "%s",
_("Failed to get valid client socket identity
groups"));
- return -1;
+ goto cleanup;
}
/* PID and process creation time are not supported on BSDs */
@@ -1188,8 +1189,11 @@
*uid = cr.cr_uid;
*gid = cr.cr_gid;
+ ret = 0;
+
+cleanup:
virObjectUnlock(sock);
- return 0;
+ return ret;
}
#else
int virNetSocketGetUNIXIdentity(virNetSocketPtr sock ATTRIBUTE_UNUSED,