From 4f24ecff0153047a4a8b53c31d8001ee79e1cab7 Mon Sep 17 00:00:00 2001 From: Andrey Ryabinin Date: Thu, 26 Jan 2017 17:27:23 +0300 Subject: [PATCH] platform/x86: intel_pmc_core: fix out-of-bounds accesses on stack 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 [andy: reverted not related changes, used BIT() macro] Signed-off-by: Andy Shevchenko --- drivers/platform/x86/intel_pmc_core.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/drivers/platform/x86/intel_pmc_core.c b/drivers/platform/x86/intel_pmc_core.c index b130b8c9b9d7..914bcd2edbde 100644 --- a/drivers/platform/x86/intel_pmc_core.c +++ b/drivers/platform/x86/intel_pmc_core.c @@ -188,8 +188,7 @@ static int pmc_core_check_read_lock_bit(void) u32 value; value = pmc_core_reg_read(pmcdev, SPT_PMC_PM_CFG_OFFSET); - return test_bit(SPT_PMC_READ_DISABLE_BIT, - (unsigned long *)&value); + return value & BIT(SPT_PMC_READ_DISABLE_BIT); } #if IS_ENABLED(CONFIG_DEBUG_FS) @@ -238,8 +237,7 @@ static int pmc_core_mtpmc_link_status(void) 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); + return value & BIT(SPT_PMC_MSG_FULL_STS_BIT); } static int pmc_core_send_msg(u32 *addr_xram) -- 2.20.1