pmc_core_mtpmc_link_status() an pmc_core_check_read_lock_bit() use
test_bit() on local 32-bit variable. This causes out-of-bounds
access since test_bit() expects object at least of 'unsigned long' size:
BUG: KASAN: stack-out-of-bounds in pmc_core_probe+0x3aa/0x3b0
Call Trace:
__asan_report_load_n_noabort+0x5c/0x80
pmc_core_probe+0x3aa/0x3b0
local_pci_probe+0xf9/0x1e0
pci_device_probe+0x27b/0x350
driver_probe_device+0x419/0x830
__driver_attach+0x15f/0x1d0
bus_for_each_dev+0x129/0x1d0
driver_attach+0x42/0x70
bus_add_driver+0x385/0x690
driver_register+0x1a9/0x3d0
__pci_register_driver+0x1a2/0x290
intel_pmc_core_driver_init+0x19/0x1b
do_one_initcall+0x12e/0x280
kernel_init_freeable+0x57c/0x623
kernel_init+0x13/0x140
ret_from_fork+0x2e/0x40
Fix this by open coding bit test. While at it, also refactor this code
a little bit.
Fixes: 173943b3dae5 ("platform/x86: intel_pmc_core: ModPhy core lanes pg status")
Signed-off-by: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
---
drivers/platform/x86/intel_pmc_core.c | 16 ++++------------
1 file changed, 4 insertions(+), 12 deletions(-)
diff --git a/drivers/platform/x86/intel_pmc_core.c b/drivers/platform/x86/intel_pmc_core.c
index b130b8c..2fb5747 100644
--- a/drivers/platform/x86/intel_pmc_core.c
+++ b/drivers/platform/x86/intel_pmc_core.c
@@ -184,12 +184,8 @@ DEFINE_DEBUGFS_ATTRIBUTE(pmc_core_dev_state, pmc_core_dev_state_get, NULL, "%llu
static int pmc_core_check_read_lock_bit(void)
{
- struct pmc_dev *pmcdev = &pmc;
- u32 value;
-
- value = pmc_core_reg_read(pmcdev, SPT_PMC_PM_CFG_OFFSET);
- return test_bit(SPT_PMC_READ_DISABLE_BIT,
- (unsigned long *)&value);
+ u32 value = pmc_core_reg_read(&pmc, SPT_PMC_PM_CFG_OFFSET);
+ return value & (1U << SPT_PMC_READ_DISABLE_BIT);
}
#if IS_ENABLED(CONFIG_DEBUG_FS)
@@ -234,12 +230,8 @@ static const struct file_operations pmc_core_ppfear_ops = {
/* This function should return link status, 0 means ready */
static int pmc_core_mtpmc_link_status(void)
{
- struct pmc_dev *pmcdev = &pmc;
- u32 value;
-
- value = pmc_core_reg_read(pmcdev, SPT_PMC_PM_STS_OFFSET);
- return test_bit(SPT_PMC_MSG_FULL_STS_BIT,
- (unsigned long *)&value);
+ u32 value = pmc_core_reg_read(&pmc, SPT_PMC_PM_STS_OFFSET);
+ return value & (1U << SPT_PMC_MSG_FULL_STS_BIT);
}
static int pmc_core_send_msg(u32 *addr_xram)
--
2.10.2
