diff --git a/volatility3/framework/plugins/linux/envars.py b/volatility3/framework/plugins/linux/envars.py index 5cbf0f502..d88d77387 100644 --- a/volatility3/framework/plugins/linux/envars.py +++ b/volatility3/framework/plugins/linux/envars.py @@ -38,6 +38,47 @@ class Envars(plugins.PluginInterface): ), ] + + @staticmethod + def variables_for_task(context, task): + """ + Yields (key, value) tuples for each of the task's env vars + """ + + # get process layer to read envars from + proc_layer_name = task.add_process_layer() + if proc_layer_name is None: + return + + proc_layer = context.layers[proc_layer_name] + + # get the size of the envars with sanity checking + envars_size = task.mm.env_end - task.mm.env_start + if not (0 < envars_size <= 8192): + vollog.debug( + f"Task {pid} {name} appears to have envars of size {envars_size} bytes which fails the sanity checking, will not extract any envars." + ) + return + + # attempt to read all envars data + try: + envar_data = proc_layer.read(task.mm.env_start, envars_size) + except exceptions.InvalidAddressException: + vollog.debug( + f"Unable to read full envars for {pid} {name} starting at virtual offset {hex(task.mm.env_start)} for {envars_size} bytes, will not extract any envars." + ) + return + + # parse envar data, envars are null terminated, keys and values are separated by '=' + envar_data = envar_data.rstrip(b"\x00") + for envar_pair in envar_data.split(b"\x00"): + try: + key, value = envar_pair.decode().split("=", 1) + except ValueError: + continue + + yield key, value + def _generator(self, tasks): """Generates a listing of processes along with environment variables""" @@ -57,56 +98,8 @@ class Envars(plugins.PluginInterface): ) ppid = 0 - # kernel threads never have an mm as they do not have userland mappings - try: - mm = task.mm - except exceptions.InvalidAddressException: - # no mm so cannot get envars - vollog.debug( - f"Unable to access mm for task {pid} {name} it is likely a kernel thread, will not extract any envars." - ) - mm = None - continue - - # if mm exists attempt to get envars - if mm: - # get process layer to read envars from - proc_layer_name = task.add_process_layer() - if proc_layer_name is None: - vollog.debug( - f"Unable to construct process layer for task {pid} {name}, will not extract any envars." - ) - continue - proc_layer = self.context.layers[proc_layer_name] - - # get the size of the envars with sanity checking - envars_size = task.mm.env_end - task.mm.env_start - if not (0 < envars_size <= 8192): - vollog.debug( - f"Task {pid} {name} appears to have envars of size {envars_size} bytes which fails the sanity checking, will not extract any envars." - ) - continue - - # attempt to read all envars data - try: - envar_data = proc_layer.read(task.mm.env_start, envars_size) - except exceptions.InvalidAddressException: - vollog.debug( - f"Unable to read full envars for {pid} {name} starting at virtual offset {hex(task.mm.env_start)} for {envars_size} bytes, will not extract any envars." - ) - continue - - # parse envar data, envars are null terminated, keys and values are separated by '=' - envar_data = envar_data.rstrip(b"\x00") - for envar_pair in envar_data.split(b"\x00"): - try: - key, value = envar_pair.decode().split("=", 1) - except ValueError: - vollog.debug( - f"Unable to extract envars for {pid} {name} starting at virtual offset {hex(task.mm.env_start)}, they don't appear to be '=' separated" - ) - continue - yield (0, (pid, ppid, name, key, value)) + for key, value in self.variables_for_task(self.context, task): + yield (0, (pid, ppid, name, key, value)) def run(self): filter_func = pslist.PsList.create_pid_filter(self.config.get("pid", None))