Re: [libvirt] PATCH: better error checking for LOCAL_PEERCRED

On 10/16/2013 10:08 AM, Brian Candler wrote: On the other hand, making someone chase a URL is less convenient than attaching the patch (ideally, sending inline the way 'git send-email' does things is preferred, but since 'git am' can also handle attachments, it's still easier on the maintainer to send through the list). That said, I went ahead and did the work for you this time around. Here's what I pushed: From aa0f09929d02ccdbf3ca9502a1fd39d90db0c690 Mon Sep 17 00:00:00 2001 From: Brian Candler <b.candler(a)pobox.com&gt; Date: Thu, 17 Oct 2013 06:21:57 -0600 Subject: [PATCH] better error checking for LOCAL_PEERCRED This patch improves the error checking in the LOCAL_PEERCRED version of virNetSocketGetUNIXIdentity, used by FreeBSD and Mac OSX. 1. The error return paths now correctly unlock the socket. This is implemented in exactly the same way as the SO_PEERCRED version, using "goto cleanup" 2. cr.cr_ngroups is initialised to -1, and cr.cr_ngroups is checked for negative and overlarge values. This means that if the getsockopt() call returns success but doesn't actually update the xucred structure, this is now caught. This happened previously when getsockopt was called with SOL_SOCKET instead of SOL_LOCAL, prior to commit 5a468b3, and resulted in random uids being accepted. Signed-off-by: Eric Blake <eblake(a)redhat.com&gt; --- src/rpc/virnetsocket.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-) diff --git a/src/rpc/virnetsocket.c b/src/rpc/virnetsocket.c index e8cdfa6..2e50f8c 100644 --- a/src/rpc/virnetsocket.c +++ b/src/rpc/virnetsocket.c @@ -1174,25 +1174,27 @@ int virNetSocketGetUNIXIdentity(virNetSocketPtr sock, { struct xucred cr; socklen_t cr_len = sizeof(cr); + int ret = -1; + virObjectLock(sock); + cr.cr_ngroups = -1; if (getsockopt(sock->fd, VIR_SOL_PEERCRED, LOCAL_PEERCRED, &cr, &cr_len) < 0) { 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 */ @@ -1201,8 +1203,11 @@ int virNetSocketGetUNIXIdentity(virNetSocketPtr sock, *uid = cr.cr_uid; *gid = cr.cr_gid; + ret = 0; + +cleanup: virObjectUnlock(sock); - return 0; + return ret; } #else int virNetSocketGetUNIXIdentity(virNetSocketPtr sock ATTRIBUTE_UNUSED, -- 1.8.3.1 -- Eric Blake eblake redhat com +1-919-301-3266 Libvirt virtualization library http://libvirt.org