From: Colin Ian King colin.king@canonical.com
[ Upstream commit 0b3a8738b76fe2087f7bc2bd59f4c78504c79180 ]
The u32 variable pci_dword is being masked with 0x1fffffff and then left shifted 23 places. The shift is a u32 operation,so a value of 0x200 or more in pci_dword will overflow the u32 and only the bottow 32 bits are assigned to addr. I don't believe this was the original intent. Fix this by casting pci_dword to a resource_size_t to ensure no overflow occurs.
Note that the mask and 12 bit left shift operation does not need this because the mask SNR_IMC_MMIO_MEM0_MASK and shift is always a 32 bit value.
Fixes: ee49532b38dd ("perf/x86/intel/uncore: Add IMC uncore support for Snow Ridge") Addresses-Coverity: ("Unintentional integer overflow") Signed-off-by: Colin Ian King colin.king@canonical.com Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Signed-off-by: Ingo Molnar mingo@kernel.org Reviewed-by: Kan Liang kan.liang@linux.intel.com Link: https://lore.kernel.org/r/20210706114553.28249-1-colin.king@canonical.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 1f7bb4898a9d..a8f02c889ae8 100644 --- a/arch/x86/events/intel/uncore_snbep.c +++ b/arch/x86/events/intel/uncore_snbep.c @@ -4701,7 +4701,7 @@ 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, mem_offset, &pci_dword); addr |= (pci_dword & SNR_IMC_MMIO_MEM0_MASK) << 12;