e1000e: write protect ICHx NVM to prevent malicious write/erase

Set the hardware to ignore all write/erase cycles to the GbE region in
the ICHx NVM.  This feature can be disabled by the WriteProtectNVM module
parameter (enabled by default) only after a hardware reset, but
the machine must be power cycled before trying to enable writes.

Signed-off-by: Bruce Allan <bruce.w.allan@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
CC: arjan@linux.intel.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

5 files changed, 100 insertions, 3 deletions

diff --git a/drivers/net/e1000e/e1000.h b/drivers/net/e1000e/e1000.h
index ac4e506b4f88..f0c48a2a6799 100644
--- a/drivers/net/e1000e/e1000.h
+++ b/drivers/net/e1000e/e1000.h
@@ -305,6 +305,7 @@ struct e1000_info {
 #define FLAG_HAS_CTRLEXT_ON_LOAD          (1 << 5)
 #define FLAG_HAS_SWSM_ON_LOAD             (1 << 6)
 #define FLAG_HAS_JUMBO_FRAMES             (1 << 7)
+#define FLAG_READ_ONLY_NVM                (1 << 8)
 #define FLAG_IS_ICH                       (1 << 9)
 #define FLAG_HAS_SMART_POWER_DOWN         (1 << 11)
 #define FLAG_IS_QUAD_PORT_A               (1 << 12)
@@ -385,6 +386,7 @@ extern bool e1000e_enable_mng_pass_thru(struct e1000_hw *hw);
 extern bool e1000e_get_laa_state_82571(struct e1000_hw *hw);
 extern void e1000e_set_laa_state_82571(struct e1000_hw *hw, bool state);
 
+extern void e1000e_write_protect_nvm_ich8lan(struct e1000_hw *hw);
 extern void e1000e_set_kmrn_lock_loss_workaround_ich8lan(struct e1000_hw *hw,
                                                  bool state);
 extern void e1000e_igp3_phy_powerdown_workaround_ich8lan(struct e1000_hw *hw);
diff --git a/drivers/net/e1000e/ethtool.c b/drivers/net/e1000e/ethtool.c
index e21c9e0f3738..5ed8e13d5fed 100644
--- a/drivers/net/e1000e/ethtool.c
+++ b/drivers/net/e1000e/ethtool.c
@@ -529,6 +529,9 @@ static int e1000_set_eeprom(struct net_device *netdev,
         if (eeprom->magic != (adapter->pdev->vendor | (adapter->pdev->device << 16)))
                 return -EFAULT;
 
+        if (adapter->flags & FLAG_READ_ONLY_NVM)
+                return -EINVAL;
+
         max_len = hw->nvm.word_size * 2;
 
         first_word = eeprom->offset >> 1;
diff --git a/drivers/net/e1000e/ich8lan.c b/drivers/net/e1000e/ich8lan.c
index 9e38452a738c..d8efba884134 100644
--- a/drivers/net/e1000e/ich8lan.c
+++ b/drivers/net/e1000e/ich8lan.c
@@ -58,6 +58,7 @@
 #define ICH_FLASH_HSFCTL                0x0006
 #define ICH_FLASH_FADDR                 0x0008
 #define ICH_FLASH_FDATA0                0x0010
+#define ICH_FLASH_PR0                   0x0074
 
 #define ICH_FLASH_READ_COMMAND_TIMEOUT  500
 #define ICH_FLASH_WRITE_COMMAND_TIMEOUT 500
@@ -150,6 +151,19 @@ union ich8_hws_flash_regacc {
         u16 regval;
 };
 
+/* ICH Flash Protected Region */
+union ich8_flash_protected_range {
+        struct ich8_pr {
+                u32 base:13;     /* 0:12 Protected Range Base */
+                u32 reserved1:2; /* 13:14 Reserved */
+                u32 rpe:1;       /* 15 Read Protection Enable */
+                u32 limit:13;    /* 16:28 Protected Range Limit */
+                u32 reserved2:2; /* 29:30 Reserved */
+                u32 wpe:1;       /* 31 Write Protection Enable */
+        } range;
+        u32 regval;
+};
+
 static s32 e1000_setup_link_ich8lan(struct e1000_hw *hw);
 static void e1000_clear_hw_cntrs_ich8lan(struct e1000_hw *hw);
 static void e1000_initialize_hw_bits_ich8lan(struct e1000_hw *hw);
@@ -1284,6 +1298,7 @@ static s32 e1000_update_nvm_checksum_ich8lan(struct e1000_hw *hw)
          * programming failed.
          */
         if (ret_val) {
+                /* Possibly read-only, see e1000e_write_protect_nvm_ich8lan() */
                 hw_dbg(hw, "Flash commit failed.\n");
                 e1000_release_swflag_ich8lan(hw);
                 return ret_val;
@@ -1374,6 +1389,49 @@ static s32 e1000_validate_nvm_checksum_ich8lan(struct e1000_hw *hw)
 }
 
 /**
+ *  e1000e_write_protect_nvm_ich8lan - Make the NVM read-only
+ *  @hw: pointer to the HW structure
+ *
+ *  To prevent malicious write/erase of the NVM, set it to be read-only
+ *  so that the hardware ignores all write/erase cycles of the NVM via
+ *  the flash control registers.  The shadow-ram copy of the NVM will
+ *  still be updated, however any updates to this copy will not stick
+ *  across driver reloads.
+ **/
+void e1000e_write_protect_nvm_ich8lan(struct e1000_hw *hw)
+{
+        union ich8_flash_protected_range pr0;
+        union ich8_hws_flash_status hsfsts;
+        u32 gfpreg;
+        s32 ret_val;
+
+        ret_val = e1000_acquire_swflag_ich8lan(hw);
+        if (ret_val)
+                return;
+
+        gfpreg = er32flash(ICH_FLASH_GFPREG);
+
+        /* Write-protect GbE Sector of NVM */
+        pr0.regval = er32flash(ICH_FLASH_PR0);
+        pr0.range.base = gfpreg & FLASH_GFPREG_BASE_MASK;
+        pr0.range.limit = ((gfpreg >> 16) & FLASH_GFPREG_BASE_MASK);
+        pr0.range.wpe = true;
+        ew32flash(ICH_FLASH_PR0, pr0.regval);
+
+        /*
+         * Lock down a subset of GbE Flash Control Registers, e.g.
+         * PR0 to prevent the write-protection from being lifted.
+         * Once FLOCKDN is set, the registers protected by it cannot
+         * be written until FLOCKDN is cleared by a hardware reset.
+         */
+        hsfsts.regval = er16flash(ICH_FLASH_HSFSTS);
+        hsfsts.hsf_status.flockdn = true;
+        ew32flash(ICH_FLASH_HSFSTS, hsfsts.regval);
+
+        e1000_release_swflag_ich8lan(hw);
+}
+
+/**
  *  e1000_write_flash_data_ich8lan - Writes bytes to the NVM
  *  @hw: pointer to the HW structure
  *  @offset: The offset (in bytes) of the byte/word to read.
diff --git a/drivers/net/e1000e/netdev.c b/drivers/net/e1000e/netdev.c
index d266510c8a94..1f767feda9a7 100644
--- a/drivers/net/e1000e/netdev.c
+++ b/drivers/net/e1000e/netdev.c
@@ -47,7 +47,7 @@
 
 #include "e1000.h"
 
-#define DRV_VERSION "0.3.3.3-k2"
+#define DRV_VERSION "0.3.3.3-k4"
 char e1000e_driver_name[] = "e1000e";
 const char e1000e_driver_version[] = DRV_VERSION;
 
@@ -4467,6 +4467,8 @@ static int __devinit e1000_probe(struct pci_dev *pdev,
 
         adapter->bd_number = cards_found++;
 
+        e1000e_check_options(adapter);
+
         /* setup adapter struct */
         err = e1000_sw_init(adapter);
         if (err)
@@ -4482,6 +4484,10 @@ static int __devinit e1000_probe(struct pci_dev *pdev,
         if (err)
                 goto err_hw_init;
 
+        if ((adapter->flags & FLAG_IS_ICH) &&
+            (adapter->flags & FLAG_READ_ONLY_NVM))
+                e1000e_write_protect_nvm_ich8lan(&adapter->hw);
+
         hw->mac.ops.get_bus_info(&adapter->hw);
 
         adapter->hw.phy.autoneg_wait_to_complete = 0;
@@ -4573,8 +4579,6 @@ static int __devinit e1000_probe(struct pci_dev *pdev,
         INIT_WORK(&adapter->reset_task, e1000_reset_task);
         INIT_WORK(&adapter->watchdog_task, e1000_watchdog_task);
 
-        e1000e_check_options(adapter);
-
         /* Initialize link parameters. User can change them with ethtool */
         adapter->hw.mac.autoneg = 1;
         adapter->fc_autoneg = 1;
diff --git a/drivers/net/e1000e/param.c b/drivers/net/e1000e/param.c
index ed912e023a72..d91dbf7ba434 100644
--- a/drivers/net/e1000e/param.c
+++ b/drivers/net/e1000e/param.c
@@ -133,6 +133,15 @@ E1000_PARAM(SmartPowerDownEnable, "Enable PHY smart power down");
  */
 E1000_PARAM(KumeranLockLoss, "Enable Kumeran lock loss workaround");
 
+/*
+ * Write Protect NVM
+ *
+ * Valid Range: 0, 1
+ *
+ * Default Value: 1 (enabled)
+ */
+E1000_PARAM(WriteProtectNVM, "Write-protect NVM [WARNING: disabling this can lead to corrupted NVM]");
+
 struct e1000_option {
         enum { enable_option, range_option, list_option } type;
         const char *name;
@@ -388,4 +397,25 @@ void __devinit e1000e_check_options(struct e1000_adapter *adapter)
                                                                        opt.def);
                 }
         }
+        { /* Write-protect NVM */
+                const struct e1000_option opt = {
+                        .type = enable_option,
+                        .name = "Write-protect NVM",
+                        .err  = "defaulting to Enabled",
+                        .def  = OPTION_ENABLED
+                };
+
+                if (adapter->flags & FLAG_IS_ICH) {
+                        if (num_WriteProtectNVM > bd) {
+                                unsigned int write_protect_nvm = WriteProtectNVM[bd];
+                                e1000_validate_option(&write_protect_nvm, &opt,
+                                                      adapter);
+                                if (write_protect_nvm)
+                                        adapter->flags |= FLAG_READ_ONLY_NVM;
+                        } else {
+                                if (opt.def)
+                                        adapter->flags |= FLAG_READ_ONLY_NVM;
+                        }
+                }
+        }
 }