[libvirt] [PATCH v2] virnetdevtap: Don't crash on !ifname in virNetDevTapInterfaceStats

https://bugzilla.redhat.com/show_bug.cgi?id=1595184 Some domain <interfaces/> do not have a name (because they are not TAP devices). Therefore, if virNetDevTapInterfaceStats(net->ifname, ...) is called an instant crash occurs. In Linux version of the function strlen() is called over the name and in BSD version STREQ() is called. Signed-off-by: Michal Privoznik <mprivozn@redhat.com> --- diff to v1: - changed the error message - fixed check in BSD version src/util/virnetdevtap.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/src/util/virnetdevtap.c b/src/util/virnetdevtap.c index bd0710ad2e..3118ca18e8 100644 --- a/src/util/virnetdevtap.c +++ b/src/util/virnetdevtap.c @@ -691,6 +691,12 @@ virNetDevTapInterfaceStats(const char *ifname, FILE *fp; char line[256], *colon; + if (!ifname) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("Interface name not provided")); + return -1; + } + fp = fopen("/proc/net/dev", "r"); if (!fp) { virReportSystemError(errno, "%s", @@ -768,6 +774,12 @@ virNetDevTapInterfaceStats(const char *ifname, struct if_data *ifd; int ret = -1; + if (!ifname) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + _("Interface name not provided")); + return -1; + } + if (getifaddrs(&ifap) < 0) { virReportSystemError(errno, "%s", _("Could not get interface list")); -- 2.16.4

On Fri, 2018-07-13 at 13:59 +0200, Michal Privoznik wrote:
https://bugzilla.redhat.com/show_bug.cgi?id=1595184
Some domain <interfaces/> do not have a name (because they are not TAP devices). Therefore, if virNetDevTapInterfaceStats(net->ifname, ...) is called an instant crash occurs. In Linux version of the function strlen() is called over the name and in BSD version STREQ() is called.
Signed-off-by: Michal Privoznik <mprivozn@redhat.com> ---
diff to v1: - changed the error message - fixed check in BSD version
src/util/virnetdevtap.c | 12 ++++++++++++
Reviewed-by: Andrea Bolognani <abologna@redhat.com> -- Andrea Bolognani / Red Hat / Virtualization
participants (2)
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Andrea Bolognani
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Michal Privoznik