]> git.baikalelectronics.ru Git - kernel.git/commit
perf/x86/intel/uncore: Fix integer overflow on 23 bit left shift of a u32
authorColin Ian King <colin.king@canonical.com>
Tue, 6 Jul 2021 11:45:53 +0000 (12:45 +0100)
committerIngo Molnar <mingo@kernel.org>
Thu, 26 Aug 2021 06:58:02 +0000 (08:58 +0200)
commitc2faa86a0b298189549f75f39738a913c78f63ef
tree4b48a9a284bcdbd7ef1f5a676a94fc70294fc6c3
parent90d6e099063df309edcf99ab5372f69a668f1989
perf/x86/intel/uncore: Fix integer overflow on 23 bit left shift of a u32

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: bceeb5fd1549 ("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
arch/x86/events/intel/uncore_snbep.c