thunderbolt: Fix NULL dereference in tb_remove_work()grafted

There is a slight race between tb_remove_work() and tb_domain_remove()
which leads to dereferencing a NULL tb->root_switch pointer inside
tb_free_unplugged_xdomains():

        Thread A                            Thread B

  tb_remove_work()
                                    tb_domain_remove()
                                      mutex_lock(&tb->lock)
                                      tb_stop()
                                        /* doesn't cancel a running callback */
                                        cancel_delayed_work(&tcm->remove_work)
                                        ...
                                        tb_switch_remove(tb->root_switch)
                                        tb->root_switch = NULL
                                      mutex_unlock(&tb->lock)
    mutex_lock(&tb->lock)
    ...
    /* without checking ->root_switch */
    tb_free_unplugged_xdomains(tb->root_switch)
    mutex_unlock(&tb->lock)

Commit a8937f35cf39 ("thunderbolt: Remove XDomain from the bus without
holding tb->lock") doesn't seem right to move tb_free_unplugged_xdomains()
out of the &tb->lock section and the check for tb->root_switch, in
particular.  It states:

  For this reason separate removing the XDomain from the topology data
  structures (where we need the lock) from unregistering the device from
  the bus (where remove callbacks of the drivers are being called).

tb_free_unplugged_xdomains() belongs to the former group of functions
requiring the lock.  And it also calls tb_xdomain_remove() which should
only be called with &tb->lock held.

Found by Linux Verification Center (linuxtesting.org) with Svace static
analysis tool.

Fixes: a8937f35cf39 ("thunderbolt: Remove XDomain from the bus without holding tb->lock")
Cc: stable@vger.kernel.org
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

1 files changed, 171 insertions, 0 deletions

diff --git a/include/uapi/sound/intel/avs/tokens.h b/include/uapi/sound/intel/avs/tokens.h
new file mode 100644
index 000000000..3ff6d9150
--- /dev/null
+++ b/include/uapi/sound/intel/avs/tokens.h
@@ -0,0 +1,171 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+/*
+ * Copyright(c) 2021 Intel Corporation
+ *
+ * Authors: Cezary Rojewski <cezary.rojewski@intel.com>
+ *          Amadeusz Slawinski <amadeuszx.slawinski@linux.intel.com>
+ */
+
+#ifndef __UAPI_SOUND_INTEL_AVS_TOKENS_H
+#define __UAPI_SOUND_INTEL_AVS_TOKENS_H
+
+enum avs_tplg_token {
+	/* struct avs_tplg */
+	AVS_TKN_MANIFEST_NAME_STRING			= 1,
+	AVS_TKN_MANIFEST_VERSION_U32			= 2,
+	AVS_TKN_MANIFEST_NUM_LIBRARIES_U32		= 3,
+	AVS_TKN_MANIFEST_NUM_AFMTS_U32			= 4,
+	AVS_TKN_MANIFEST_NUM_MODCFGS_BASE_U32		= 5,
+	AVS_TKN_MANIFEST_NUM_MODCFGS_EXT_U32		= 6,
+	AVS_TKN_MANIFEST_NUM_PPLCFGS_U32		= 7,
+	AVS_TKN_MANIFEST_NUM_BINDINGS_U32		= 8,
+	AVS_TKN_MANIFEST_NUM_CONDPATH_TMPLS_U32		= 9,
+	AVS_TKN_MANIFEST_NUM_INIT_CONFIGS_U32		= 10,
+	AVS_TKN_MANIFEST_NUM_NHLT_CONFIGS_U32		= 11,
+
+	/* struct avs_tplg_library */
+	AVS_TKN_LIBRARY_ID_U32				= 101,
+	AVS_TKN_LIBRARY_NAME_STRING			= 102,
+
+	/* struct avs_audio_format */
+	AVS_TKN_AFMT_ID_U32				= 201,
+	AVS_TKN_AFMT_SAMPLE_RATE_U32			= 202,
+	AVS_TKN_AFMT_BIT_DEPTH_U32			= 203,
+	AVS_TKN_AFMT_CHANNEL_MAP_U32			= 204,
+	AVS_TKN_AFMT_CHANNEL_CFG_U32			= 205,
+	AVS_TKN_AFMT_INTERLEAVING_U32			= 206,
+	AVS_TKN_AFMT_NUM_CHANNELS_U32			= 207,
+	AVS_TKN_AFMT_VALID_BIT_DEPTH_U32		= 208,
+	AVS_TKN_AFMT_SAMPLE_TYPE_U32			= 209,
+
+	/* struct avs_tplg_modcfg_base */
+	AVS_TKN_MODCFG_BASE_ID_U32			= 301,
+	AVS_TKN_MODCFG_BASE_CPC_U32			= 302,
+	AVS_TKN_MODCFG_BASE_IBS_U32			= 303,
+	AVS_TKN_MODCFG_BASE_OBS_U32			= 304,
+	AVS_TKN_MODCFG_BASE_PAGES_U32			= 305,
+
+	/* struct avs_tplg_modcfg_ext */
+	AVS_TKN_MODCFG_EXT_ID_U32			= 401,
+	AVS_TKN_MODCFG_EXT_TYPE_UUID			= 402,
+	AVS_TKN_MODCFG_CPR_OUT_AFMT_ID_U32		= 403,
+	AVS_TKN_MODCFG_CPR_FEATURE_MASK_U32		= 404,
+	AVS_TKN_MODCFG_CPR_DMA_TYPE_U32			= 405,
+	AVS_TKN_MODCFG_CPR_DMABUFF_SIZE_U32		= 406,
+	AVS_TKN_MODCFG_CPR_VINDEX_U8			= 407,
+	AVS_TKN_MODCFG_CPR_BLOB_FMT_ID_U32		= 408,
+	AVS_TKN_MODCFG_MICSEL_OUT_AFMT_ID_U32		= 409,
+	AVS_TKN_MODCFG_INTELWOV_CPC_LP_MODE_U32		= 410,
+	AVS_TKN_MODCFG_SRC_OUT_FREQ_U32			= 411,
+	AVS_TKN_MODCFG_MUX_REF_AFMT_ID_U32		= 412,
+	AVS_TKN_MODCFG_MUX_OUT_AFMT_ID_U32		= 413,
+	AVS_TKN_MODCFG_AEC_REF_AFMT_ID_U32		= 414,
+	AVS_TKN_MODCFG_AEC_OUT_AFMT_ID_U32		= 415,
+	AVS_TKN_MODCFG_AEC_CPC_LP_MODE_U32		= 416,
+	AVS_TKN_MODCFG_ASRC_OUT_FREQ_U32		= 417,
+	AVS_TKN_MODCFG_ASRC_MODE_U8			= 418,
+	AVS_TKN_MODCFG_ASRC_DISABLE_JITTER_U8		= 419,
+	AVS_TKN_MODCFG_UPDOWN_MIX_OUT_CHAN_CFG_U32	= 420,
+	AVS_TKN_MODCFG_UPDOWN_MIX_COEFF_SELECT_U32	= 421,
+	AVS_TKN_MODCFG_UPDOWN_MIX_COEFF_0_S32		= 422,
+	AVS_TKN_MODCFG_UPDOWN_MIX_COEFF_1_S32		= 423,
+	AVS_TKN_MODCFG_UPDOWN_MIX_COEFF_2_S32		= 424,
+	AVS_TKN_MODCFG_UPDOWN_MIX_COEFF_3_S32		= 425,
+	AVS_TKN_MODCFG_UPDOWN_MIX_COEFF_4_S32		= 426,
+	AVS_TKN_MODCFG_UPDOWN_MIX_COEFF_5_S32		= 427,
+	AVS_TKN_MODCFG_UPDOWN_MIX_COEFF_6_S32		= 428,
+	AVS_TKN_MODCFG_UPDOWN_MIX_COEFF_7_S32		= 429,
+	AVS_TKN_MODCFG_UPDOWN_MIX_CHAN_MAP_U32		= 430,
+	AVS_TKN_MODCFG_EXT_NUM_INPUT_PINS_U16		= 431,
+	AVS_TKN_MODCFG_EXT_NUM_OUTPUT_PINS_U16		= 432,
+	AVS_TKN_MODCFG_WHM_REF_AFMT_ID_U32		= 433,
+	AVS_TKN_MODCFG_WHM_OUT_AFMT_ID_U32		= 434,
+	AVS_TKN_MODCFG_WHM_WAKE_TICK_PERIOD_U32		= 435,
+	AVS_TKN_MODCFG_WHM_VINDEX_U8			= 436,
+	AVS_TKN_MODCFG_WHM_DMA_TYPE_U32			= 437,
+	AVS_TKN_MODCFG_WHM_DMABUFF_SIZE_U32		= 438,
+	AVS_TKN_MODCFG_WHM_BLOB_AFMT_ID_U32		= 439,
+	AVS_TKN_MODCFG_PEAKVOL_VOLUME_U32		= 440,
+	AVS_TKN_MODCFG_PEAKVOL_CHANNEL_ID_U32		= 441, /* reserved */
+	AVS_TKN_MODCFG_PEAKVOL_CURVE_TYPE_U32		= 442,
+	AVS_TKN_MODCFG_PEAKVOL_CURVE_DURATION_U32	= 443,
+
+	/* struct avs_tplg_pplcfg */
+	AVS_TKN_PPLCFG_ID_U32				= 1401,
+	AVS_TKN_PPLCFG_REQ_SIZE_U16			= 1402,
+	AVS_TKN_PPLCFG_PRIORITY_U8			= 1403,
+	AVS_TKN_PPLCFG_LOW_POWER_BOOL			= 1404,
+	AVS_TKN_PPLCFG_ATTRIBUTES_U16			= 1405,
+	AVS_TKN_PPLCFG_TRIGGER_U32			= 1406,
+
+	/* struct avs_tplg_binding */
+	AVS_TKN_BINDING_ID_U32				= 1501,
+	AVS_TKN_BINDING_TARGET_TPLG_NAME_STRING		= 1502,
+	AVS_TKN_BINDING_TARGET_PATH_TMPL_ID_U32		= 1503,
+	AVS_TKN_BINDING_TARGET_PPL_ID_U32		= 1504,
+	AVS_TKN_BINDING_TARGET_MOD_ID_U32		= 1505,
+	AVS_TKN_BINDING_TARGET_MOD_PIN_U8		= 1506,
+	AVS_TKN_BINDING_MOD_ID_U32			= 1507,
+	AVS_TKN_BINDING_MOD_PIN_U8			= 1508,
+	AVS_TKN_BINDING_IS_SINK_U8			= 1509,
+
+	/* struct avs_tplg_pipeline */
+	AVS_TKN_PPL_ID_U32				= 1601,
+	AVS_TKN_PPL_PPLCFG_ID_U32			= 1602,
+	AVS_TKN_PPL_NUM_BINDING_IDS_U32			= 1603,
+	AVS_TKN_PPL_BINDING_ID_U32			= 1604,
+
+	/* struct avs_tplg_module */
+	AVS_TKN_MOD_ID_U32				= 1701,
+	AVS_TKN_MOD_MODCFG_BASE_ID_U32			= 1702,
+	AVS_TKN_MOD_IN_AFMT_ID_U32			= 1703,
+	AVS_TKN_MOD_CORE_ID_U8				= 1704,
+	AVS_TKN_MOD_PROC_DOMAIN_U8			= 1705,
+	AVS_TKN_MOD_MODCFG_EXT_ID_U32			= 1706,
+	AVS_TKN_MOD_KCONTROL_ID_U32			= 1707,
+	AVS_TKN_MOD_INIT_CONFIG_NUM_IDS_U32		= 1708,
+	AVS_TKN_MOD_INIT_CONFIG_ID_U32			= 1709,
+	AVS_TKN_MOD_NHLT_CONFIG_ID_U32			= 1710,
+
+	/* struct avs_tplg_path_template */
+	AVS_TKN_PATH_TMPL_ID_U32			= 1801,
+
+	/* struct avs_tplg_path */
+	AVS_TKN_PATH_ID_U32				= 1901,
+	AVS_TKN_PATH_FE_FMT_ID_U32			= 1902,
+	AVS_TKN_PATH_BE_FMT_ID_U32			= 1903,
+
+	/* struct avs_tplg_path_template (conditional) */
+	AVS_TKN_CONDPATH_TMPL_ID_U32			= 1801,
+	AVS_TKN_CONDPATH_TMPL_SOURCE_TPLG_NAME_STRING	= 2002,
+	AVS_TKN_CONDPATH_TMPL_SOURCE_PATH_TMPL_ID_U32	= 2003,
+	AVS_TKN_CONDPATH_TMPL_SINK_TPLG_NAME_STRING	= 2004,
+	AVS_TKN_CONDPATH_TMPL_SINK_PATH_TMPL_ID_U32	= 2005,
+	AVS_TKN_CONDPATH_TMPL_COND_TYPE_U32		= 2006,
+	AVS_TKN_CONDPATH_TMPL_OVERRIDABLE_BOOL		= 2007,
+	AVS_TKN_CONDPATH_TMPL_PRIORITY_U8		= 2008,
+
+	/* struct avs_tplg_path (conditional) */
+	AVS_TKN_CONDPATH_ID_U32				= 1901,
+	AVS_TKN_CONDPATH_SOURCE_PATH_ID_U32		= 2102,
+	AVS_TKN_CONDPATH_SINK_PATH_ID_U32		= 2103,
+
+	/* struct avs_tplg_pin_format */
+	AVS_TKN_PIN_FMT_INDEX_U32			= 2201,
+	AVS_TKN_PIN_FMT_IOBS_U32			= 2202,
+	AVS_TKN_PIN_FMT_AFMT_ID_U32			= 2203,
+
+	/* struct avs_tplg_kcontrol */
+	AVS_TKN_KCONTROL_ID_U32				= 2301,
+
+	/* struct avs_tplg_init_config */
+	AVS_TKN_INIT_CONFIG_ID_U32			= 2401,
+	AVS_TKN_INIT_CONFIG_PARAM_U8			= 2402,
+	AVS_TKN_INIT_CONFIG_LENGTH_U32			= 2403,
+
+	/* struct avs_tplg_nhlt_config */
+	AVS_TKN_NHLT_CONFIG_ID_U32			= 2501,
+	AVS_TKN_NHLT_CONFIG_SIZE_U32			= 2502,
+};
+
+#endif