Messages in this thread Patch in this message | | | From | Mark Salter <> | Subject | [PATCH] arm64: fix NULL dereference in have_cpu_die() | Date | Fri, 24 Mar 2017 09:53:56 -0400 |
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Commit 5c492c3f5255 ("arm64: smp: Add function to determine if cpus are stuck in the kernel") added a helper function to determine if die() is supported in cpu_ops. This function assumes a cpu will have a valid cpu_ops entry, but that may not be the case for cpu0 is spin-table or parking protocol is used to boot secondary cpus. In that case, there is a NULL dereference if have_cpu_die() is called by cpu0. So add a check for a valid cpu_ops before dereferencing it.
Fixes: 5c492c3f5255 ("arm64: smp: Add function to determine if cpus are stuck in the kernel") Signed-off-by: Mark Salter <msalter@redhat.com> --- arch/arm64/kernel/smp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index ef1caae..9b10365 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -944,7 +944,7 @@ static bool have_cpu_die(void) #ifdef CONFIG_HOTPLUG_CPU int any_cpu = raw_smp_processor_id(); - if (cpu_ops[any_cpu]->cpu_die) + if (cpu_ops[any_cpu] && cpu_ops[any_cpu]->cpu_die) return true; #endif return false; -- 2.9.3
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