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authorMark Salter <msalter@redhat.com>2017-03-24 09:53:56 -0400
committerWill Deacon <will.deacon@arm.com>2017-03-30 17:14:32 +0100
commit335d2c2d192266358c5dfa64953a4c162f46e464 (patch)
treea4fb36583f7b7c162d33cf882f250e5e070d7e08 /arch
parentLinux 4.11-rc4 (diff)
downloadlinux-dev-335d2c2d192266358c5dfa64953a4c162f46e464.tar.xz
linux-dev-335d2c2d192266358c5dfa64953a4c162f46e464.zip
arm64: fix NULL dereference in have_cpu_die()
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> Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm64/kernel/smp.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index ef1caae02110..9b1036570586 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;