Commit f69a23b7 authored Jun 05, 2012 by Johannes Berg Committed by John W. Linville Jun 05, 2012

iwlwifi: fix double free/complete in firmware loading



Linus reported that due to mac80211 failing to register
the device (due to WoWLAN) his machine crashed etc. as
we double-freed the vmalloc() firmware area. His patch
to fix it was very similar to this one but I noticed
that there's another bug in the area: we complete the
completion before starting, so since we're running in
a work struct context stop() could be called while in
the middle of start() which will almost certainly lead
to issues.

Make a modification similar to his to avoid the double-
free but also move the completion to another spot so it
is only done after start() either finished or failed so
that stop() can have a consistent state.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

parent fcb6ff5e

drivers/net/wireless/iwlwifi/iwl-drv.c

+7 −2

Original line number	Diff line number	Diff line
		@@ -861,13 +861,18 @@ static void iwl_ucode_callback(const struct firmware ucode_raw, void context)

		/* We have our copies now, allow OS release its copies */
		release_firmware(ucode_raw);
		complete(&drv->request_firmware_complete);

		drv->op_mode = iwl_dvm_ops.start(drv->trans, drv->cfg, &drv->fw);

		if (!drv->op_mode)
		goto out_free_fw;
		goto out_unbind;

		/*
		* Complete the firmware request last so that
		* a driver unbind (stop) doesn't run while we
		* are doing the start() above.
		*/
		complete(&drv->request_firmware_complete);
		return;

		try_again: