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From: Luca Coelho <luca@coelho.fi>
To: kvalo@codeaurora.org
Cc: linux-wireless@vger.kernel.org
Subject: [PATCH 10/12] iwlwifi: pcie: make cfg vs. trans_cfg more robust
Date: Tue, 30 Mar 2021 16:24:58 +0300	[thread overview]
Message-ID: <iwlwifi.20210330162204.6f69fe6e4128.I921d4ae20ef5276716baeeeda0b001cf25b9b968@changeid> (raw)
In-Reply-To: <20210330132500.468321-1-luca@coelho.fi>

From: Johannes Berg <johannes.berg@intel.com>

If we (for example) have a trans_cfg entry in the PCI IDs table,
but then don't find a full cfg entry for it in the info table,
we fall through to the code that treats the PCI ID table entry
as a full cfg entry. This obviously causes crashes later, e.g.
when trying to build the firmware name string.

Avoid such crashes by using the low bit of the pointer as a tag
for trans_cfg entries (automatically using a macro that checks
the type when assigning) and then checking that before trying to
use the data as a full entry - if it's just a partial entry at
that point, fail.

Since we're adding some macro magic, also check that the type is
in fact either struct iwl_cfg_trans_params or struct iwl_cfg,
failing compilation ("initializer element is not constant") if
it isn't.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
---
 drivers/net/wireless/intel/iwlwifi/pcie/drv.c | 35 +++++++++++++++----
 1 file changed, 28 insertions(+), 7 deletions(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c
index f4a36ebfa0ee..15561a14a098 100644
--- a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c
+++ b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c
@@ -17,10 +17,20 @@
 #include "iwl-prph.h"
 #include "internal.h"
 
+#define TRANS_CFG_MARKER BIT(0)
+#define _IS_A(cfg, _struct) __builtin_types_compatible_p(typeof(cfg),	\
+							 struct _struct)
+extern int _invalid_type;
+#define _TRANS_CFG_MARKER(cfg)						\
+	(__builtin_choose_expr(_IS_A(cfg, iwl_cfg_trans_params),	\
+			       TRANS_CFG_MARKER,			\
+	 __builtin_choose_expr(_IS_A(cfg, iwl_cfg), 0, _invalid_type)))
+#define _ASSIGN_CFG(cfg) (_TRANS_CFG_MARKER(cfg) + (kernel_ulong_t)&(cfg))
+
 #define IWL_PCI_DEVICE(dev, subdev, cfg) \
 	.vendor = PCI_VENDOR_ID_INTEL,  .device = (dev), \
 	.subvendor = PCI_ANY_ID, .subdevice = (subdev), \
-	.driver_data = (kernel_ulong_t)&(cfg)
+	.driver_data = _ASSIGN_CFG(cfg)
 
 /* Hardware specific file defines the PCI IDs table for that hardware module */
 static const struct pci_device_id iwl_hw_card_ids[] = {
@@ -1074,19 +1084,22 @@ static const struct iwl_dev_info iwl_dev_info_table[] = {
 
 static int iwl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 {
-	const struct iwl_cfg_trans_params *trans =
-		(struct iwl_cfg_trans_params *)(ent->driver_data);
+	const struct iwl_cfg_trans_params *trans;
 	const struct iwl_cfg *cfg_7265d __maybe_unused = NULL;
 	struct iwl_trans *iwl_trans;
 	struct iwl_trans_pcie *trans_pcie;
 	int i, ret;
+	const struct iwl_cfg *cfg;
+
+	trans = (void *)(ent->driver_data & ~TRANS_CFG_MARKER);
+
 	/*
 	 * This is needed for backwards compatibility with the old
 	 * tables, so we don't need to change all the config structs
 	 * at the same time.  The cfg is used to compare with the old
 	 * full cfg structs.
 	 */
-	const struct iwl_cfg *cfg = (struct iwl_cfg *)(ent->driver_data);
+	cfg = (void *)(ent->driver_data & ~TRANS_CFG_MARKER);
 
 	/* make sure trans is the first element in iwl_cfg */
 	BUILD_BUG_ON(offsetof(struct iwl_cfg, trans));
@@ -1201,11 +1214,19 @@ static int iwl_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 #endif
 	/*
-	 * If we didn't set the cfg yet, assume the trans is actually
-	 * a full cfg from the old tables.
+	 * If we didn't set the cfg yet, the PCI ID table entry should have
+	 * been a full config - if yes, use it, otherwise fail.
 	 */
-	if (!iwl_trans->cfg)
+	if (!iwl_trans->cfg) {
+		if (ent->driver_data & TRANS_CFG_MARKER) {
+			pr_err("No config found for PCI dev %04x/%04x, rev=0x%x, rfid=0x%x\n",
+			       pdev->device, pdev->subsystem_device,
+			       iwl_trans->hw_rev, iwl_trans->hw_rf_id);
+			ret = -EINVAL;
+			goto out_free_trans;
+		}
 		iwl_trans->cfg = cfg;
+	}
 
 	/* if we don't have a name yet, copy name from the old cfg */
 	if (!iwl_trans->name)
-- 
2.31.0


  parent reply	other threads:[~2021-03-30 13:26 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-03-30 13:24 [PATCH 00/12] iwlwifi: updates intended for v5.13 2021-03-30 Luca Coelho
2021-03-30 13:24 ` [PATCH 01/12] iwlwifi: mvm: enable TX on new CSA channel before disconnecting Luca Coelho
2021-04-12 10:09   ` Luca Coelho
2021-04-13  5:56   ` [01/12] " Luca Coelho
2021-03-30 13:24 ` [PATCH 02/12] iwlwifi: pcie: avoid unnecessarily taking spinlock Luca Coelho
2021-03-30 13:24 ` [PATCH 03/12] iwlwifi: pcie: normally grab NIC access for inflight-hcmd Luca Coelho
2021-03-30 13:24 ` [PATCH 04/12] iwlwifi: mvm: don't allow CSA if we haven't been fully associated Luca Coelho
2021-03-30 13:24 ` [PATCH 05/12] iwlwifi: pcie: Add support for Bz Family Luca Coelho
2021-03-30 13:24 ` [PATCH 06/12] iwlwifi: change step in so-gf struct Luca Coelho
2021-03-30 13:24 ` [PATCH 07/12] iwlwifi: change name to AX 211 and 411 family Luca Coelho
2021-03-30 13:24 ` [PATCH 08/12] iwlwifi: add 160Mhz to killer 1550 name Luca Coelho
2021-03-30 13:24 ` [PATCH 09/12] iwlwifi: pcie: clear only FH bits handle in the interrupt Luca Coelho
2021-03-30 13:24 ` Luca Coelho [this message]
2021-03-30 13:24 ` [PATCH 11/12] iwlwifi: mvm: support range request command version 12 Luca Coelho
2021-03-30 13:25 ` [PATCH 12/12] iwlwifi: mvm: responder: support responder config command version 8 Luca Coelho

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