[PATCH] perf/x86/intel/uncore: fix integer overflow on shift of a u32 integer

From: Colin King
Date: Wed Oct 02 2019 - 07:56:22 EST


From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

Shifting the u32 integer result of (pci_dword & SNR_IMC_MMIO_BASE_MASK)
will end up with an overflow when pci_dword greater than 0x1ff. Fix this
by casting pci_dword to a resource_size_t before masking and shifting it.

Addresses-Coverity: ("Unintentional integer overflow")
Fixes: ee49532b38dd ("perf/x86/intel/uncore: Add IMC uncore support for Snow Ridge")
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
---
arch/x86/events/intel/uncore_snbep.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/events/intel/uncore_snbep.c b/arch/x86/events/intel/uncore_snbep.c
index b10a5ec79e48..ed69df1340d9 100644
--- a/arch/x86/events/intel/uncore_snbep.c
+++ b/arch/x86/events/intel/uncore_snbep.c
@@ -4415,7 +4415,7 @@ static void snr_uncore_mmio_init_box(struct intel_uncore_box *box)
return;

pci_read_config_dword(pdev, SNR_IMC_MMIO_BASE_OFFSET, &pci_dword);
- addr = (pci_dword & SNR_IMC_MMIO_BASE_MASK) << 23;
+ addr = ((resource_size_t)pci_dword & SNR_IMC_MMIO_BASE_MASK) << 23;

pci_read_config_dword(pdev, SNR_IMC_MMIO_MEM0_OFFSET, &pci_dword);
addr |= (pci_dword & SNR_IMC_MMIO_MEM0_MASK) << 12;
--
2.20.1