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perf/x86/intel/uncore: Fix integer overflow on 23 bit left shift of a u32

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[ 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>
This commit is contained in:
Colin Ian King 2021-07-06 12:45:53 +01:00 committed by Greg Kroah-Hartman
parent 0ad96094ab
commit baf56a1d81
1 changed files with 1 additions and 1 deletions
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2
arch/x86/events/intel/uncore_snbep.c
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@ -4382,7 +4382,7 @@ 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;