From: Johannes Berg johannes.berg@intel.com
[ Upstream commit 48a5494d6a4cb5812f0640d9515f1876ffc7a013 ]
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 Link: https://lore.kernel.org/r/iwlwifi.20210330162204.6f69fe6e4128.I921d4ae20ef52... Signed-off-by: Luca Coelho luciano.coelho@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 500fdb0b6c42..eeb70560b746 100644 --- a/drivers/net/wireless/intel/iwlwifi/pcie/drv.c +++ b/drivers/net/wireless/intel/iwlwifi/pcie/drv.c @@ -73,10 +73,20 @@ #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[] = { @@ -1018,20 +1028,23 @@ 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; unsigned long flags; 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)); @@ -1133,11 +1146,19 @@ 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)