Commit 581f08ba authored by Dr. David Alan Gilbert's avatar Dr. David Alan Gilbert Committed by Juan Quintela
Browse files

migration: Check for ID length 



The qdev id of a device can be huge if it's on the end of a chain
of bridges; in reality such chains shouldn't occur but they can
be made to by chaining PCIe bridges together.

The migration format has a number of 256 character long format
limits; check we don't hit them (we already use pstrcat/cpy but
that just protects us from buffer overruns, we fairly quickly
hit an assert).

Signed-off-by: default avatarDr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: default avatarJuan Quintela <quintela@redhat.com>
Message-Id: <20170202125956.21942-3-dgilbert@redhat.com>
Signed-off-by: default avatarJuan Quintela <quintela@redhat.com>
parent bc5c4f21

include/migration/vmstate.h

+2 −0
Original line number Diff line number Diff line
@@ -985,12 +985,14 @@ void vmstate_save_state(QEMUFile *f, const VMStateDescription *vmsd, 


bool vmstate_save_needed(const VMStateDescription *vmsd, void *opaque);



/* Returns: 0 on success, -1 on failure */

int vmstate_register_with_alias_id(DeviceState *dev, int instance_id,

                                   const VMStateDescription *vmsd,

                                   void *base, int alias_id,

                                   int required_for_version,

                                   Error **errp);



/* Returns: 0 on success, -1 on failure */

static inline int vmstate_register(DeviceState *dev, int instance_id,

                                   const VMStateDescription *vmsd,

                                   void *opaque)

migration/savevm.c

+16 −5
Original line number Diff line number Diff line
@@ -590,8 +590,14 @@ int register_savevm_live(DeviceState *dev, 
    if (dev) {

        char *id = qdev_get_dev_path(dev);

        if (id) {

            pstrcpy(se->idstr, sizeof(se->idstr), id);

            pstrcat(se->idstr, sizeof(se->idstr), "/");

            if (snprintf(se->idstr, sizeof(se->idstr), "%s/", id) >=

                sizeof(se->idstr)) {

                error_report("Path too long for VMState (%s)", id);

                g_free(id);

                g_free(se);



                return -1;

            }

            g_free(id);



            se->compat = g_new0(CompatEntry, 1);
@@ -674,9 +680,14 @@ int vmstate_register_with_alias_id(DeviceState *dev, int instance_id, 
    if (dev) {

        char *id = qdev_get_dev_path(dev);

        if (id) {

            pstrcpy(se->idstr, sizeof(se->idstr), id);

            pstrcat(se->idstr, sizeof(se->idstr), "/");

            if (snprintf(se->idstr, sizeof(se->idstr), "%s/", id) >=

                sizeof(se->idstr)) {

                error_setg(errp, "Path too long for VMState (%s)", id);

                g_free(id);

                g_free(se);



                return -1;

            }



            se->compat = g_new0(CompatEntry, 1);

            pstrcpy(se->compat->idstr, sizeof(se->compat->idstr), vmsd->name);