diff options
| author | Petr Vandrovec <petr@vmware.com> | 2012-03-08 13:33:24 -0800 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2012-03-30 03:31:58 -0400 |
| commit | ac909ec308ce8d5177963c780564824d12bc3fa2 (patch) | |
| tree | 490e9168b304a93606de30fe01c9c5b0dc9fbc32 | |
| parent | c80f5b31f3c55a197f5323b93d1e3553429a427e (diff) | |
ACPI: Fix use-after-free in acpi_map_lsapic
When processor is being hot-added to the system, acpi_map_lsapic invokes
ACPI _MAT method to find APIC ID and flags, verifies that returned structure
is indeed ACPI's local APIC structure, and that flags contain MADT_ENABLED
bit. Then saves APIC ID, frees structure - and accesses structure when
computing arguments for acpi_register_lapic call. Which sometime leads
to acpi_register_lapic call being made with second argument zero, failing
to bring processor online with error 'Unable to map lapic to logical cpu
number'.
As lapic->lapic_flags & ACPI_MADT_ENABLED was already confirmed to be non-zero
few lines above, we can just pass unconditional ACPI_MADT_ENABLED to the
acpi_register_lapic.
Signed-off-by: Petr Vandrovec <petr@vmware.com>
Signed-off-by: Alok N Kataria <akataria@vmware.com>
Reviewed-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
| -rw-r--r-- | arch/x86/kernel/acpi/boot.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c index ce664f33ea8e..bbcc2c389ade 100644 --- a/arch/x86/kernel/acpi/boot.c +++ b/arch/x86/kernel/acpi/boot.c @@ -642,6 +642,7 @@ static int __cpuinit _acpi_map_lsapic(acpi_handle handle, int *pcpu) kfree(buffer.pointer); buffer.length = ACPI_ALLOCATE_BUFFER; buffer.pointer = NULL; + lapic = NULL; if (!alloc_cpumask_var(&tmp_map, GFP_KERNEL)) goto out; @@ -650,7 +651,7 @@ static int __cpuinit _acpi_map_lsapic(acpi_handle handle, int *pcpu) goto free_tmp_map; cpumask_copy(tmp_map, cpu_present_mask); - acpi_register_lapic(physid, lapic->lapic_flags & ACPI_MADT_ENABLED); + acpi_register_lapic(physid, ACPI_MADT_ENABLED); /* * If mp_register_lapic successfully generates a new logical cpu |