util: Fix stack smashing in virNetDevGetFamilyId

After commit 8708ca01c0 libvirtd consistently aborts with "stack
 smashing detected" when nodedev driver is initialized.

This is caused by nlmsg_parse() being told that its array of nlattr*
has CTRL_CMD_MAX (10) entries, when in fact it is declared to have
CTRL_ATTR_MAX (8) entries. Since all the entries are initialized to
NULL, the result is that nlmsg_parse is overwriting 2*(sizof(nlattr*))
bytes outside the array.

Signed-off-by: Laine Stump <laine@laine.org>
Reviewed-by: John Ferlan <jferlan@redhat.com>
Signed-off-by: Jiri Denemark <jdenemar@redhat.com>
This commit is contained in:
Laine Stump 2017-09-21 13:57:30 -04:00 committed by Jiri Denemark
parent b1d87f9ad9
commit 17825e8ae7

View File

@ -3183,7 +3183,7 @@ virNetDevGetFamilyId(const char *family_name)
if (virNetlinkCommand(nl_msg, &resp, &recvbuflen, 0, 0, NETLINK_GENERIC, 0) < 0)
goto cleanup;
if (nlmsg_parse(resp, sizeof(struct nlmsghdr), tb, CTRL_CMD_MAX, NULL) < 0) {
if (nlmsg_parse(resp, sizeof(struct nlmsghdr), tb, CTRL_ATTR_MAX, NULL) < 0) {
virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
_("malformed netlink response message"));
goto cleanup;