queue-6.8/cxl-core-regs-fix-usage-of-map-reg_type-in-cxl_decod.patch

   1 From 5382167bdfd3a20cebcd0f0f4ff8d20c6a3f0a8e Mon Sep 17 00:00:00 2001
   2 From: Sasha Levin <sashal@kernel.org>
   3 Date: Tue, 19 Mar 2024 11:15:08 -0700
   4 Subject: cxl/core/regs: Fix usage of map->reg_type in cxl_decode_regblock()
   5  before assigned
   6
   7 From: Dave Jiang <dave.jiang@intel.com>
   8
   9 [ Upstream commit 5c88a9ccd4c431d58b532e4158b6999a8350062c ]
  10
  11 In the error path, map->reg_type is being used for kernel warning
  12 before its value is setup. Found by code inspection. Exposure to
  13 user is wrong reg_type being emitted via kernel log. Use a local
  14 var for reg_type and retrieve value for usage.
  15
  16 Fixes: 6c7f4f1e51c2 ("cxl/core/regs: Make cxl_map_{component, device}_regs() device generic")
  17 Reviewed-by: Dan Williams <dan.j.williams@intel.com>
  18 Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
  19 Signed-off-by: Dave Jiang <dave.jiang@intel.com>
  20 Signed-off-by: Sasha Levin <sashal@kernel.org>
  21 ---
  22  drivers/cxl/core/regs.c | 5 +++--
  23  1 file changed, 3 insertions(+), 2 deletions(-)
  24
  25 diff --git a/drivers/cxl/core/regs.c b/drivers/cxl/core/regs.c
  26 index 372786f809555..3c42f984eeafa 100644
  27 --- a/drivers/cxl/core/regs.c
  28 +++ b/drivers/cxl/core/regs.c
  29 @@ -271,6 +271,7 @@ EXPORT_SYMBOL_NS_GPL(cxl_map_device_regs, CXL);
  30  static bool cxl_decode_regblock(struct pci_dev *pdev, u32 reg_lo, u32 reg_hi,
  31                                 struct cxl_register_map *map)
  32  {
  33 +       u8 reg_type = FIELD_GET(CXL_DVSEC_REG_LOCATOR_BLOCK_ID_MASK, reg_lo);
  34         int bar = FIELD_GET(CXL_DVSEC_REG_LOCATOR_BIR_MASK, reg_lo);
  35         u64 offset = ((u64)reg_hi << 32) |
  36                      (reg_lo & CXL_DVSEC_REG_LOCATOR_BLOCK_OFF_LOW_MASK);
  37 @@ -278,11 +279,11 @@ static bool cxl_decode_regblock(struct pci_dev *pdev, u32 reg_lo, u32 reg_hi,
  38         if (offset > pci_resource_len(pdev, bar)) {
  39                 dev_warn(&pdev->dev,
  40                          "BAR%d: %pr: too small (offset: %pa, type: %d)\n", bar,
  41 -                        &pdev->resource[bar], &offset, map->reg_type);
  42 +                        &pdev->resource[bar], &offset, reg_type);
  43                 return false;
  44         }
  45
  46 -       map->reg_type = FIELD_GET(CXL_DVSEC_REG_LOCATOR_BLOCK_ID_MASK, reg_lo);
  47 +       map->reg_type = reg_type;
  48         map->resource = pci_resource_start(pdev, bar) + offset;
  49         map->max_size = pci_resource_len(pdev, bar) - offset;
  50         return true;
  51 --
  52 2.43.0
  53