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authorJames Morse <james.morse@arm.com>2022-04-08 18:22:19 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-04-15 14:18:36 +0200
commit00914290958d6f458fe118f2fe2451799f92c0a5 (patch)
treecac0cfd8d8e4913dd770c6c9e880d38c4231f501 /arch
parent18e0097daf8c0d7897b2847d06f06b3bf44dd59e (diff)
KVM: arm64: Check arm64_get_bp_hardening_data() didn't return NULL
Will reports that with CONFIG_EXPERT=y and CONFIG_HARDEN_BRANCH_PREDICTOR=n, the kernel dereferences a NULL pointer during boot: [ 2.384444] Internal error: Oops: 96000004 [#1] PREEMPT SMP [ 2.384461] pstate: 20400085 (nzCv daIf +PAN -UAO) [ 2.384472] pc : cpu_hyp_reinit+0x114/0x30c [ 2.384476] lr : cpu_hyp_reinit+0x80/0x30c [ 2.384529] Call trace: [ 2.384533] cpu_hyp_reinit+0x114/0x30c [ 2.384537] _kvm_arch_hardware_enable+0x30/0x54 [ 2.384541] flush_smp_call_function_queue+0xe4/0x154 [ 2.384544] generic_smp_call_function_single_interrupt+0x10/0x18 [ 2.384549] ipi_handler+0x170/0x2b0 [ 2.384555] handle_percpu_devid_fasteoi_ipi+0x120/0x1cc [ 2.384560] __handle_domain_irq+0x9c/0xf4 [ 2.384563] gic_handle_irq+0x6c/0xe4 [ 2.384566] el1_irq+0xf0/0x1c0 [ 2.384570] arch_cpu_idle+0x28/0x44 [ 2.384574] do_idle+0x100/0x2a8 [ 2.384577] cpu_startup_entry+0x20/0x24 [ 2.384581] secondary_start_kernel+0x1b0/0x1cc [ 2.384589] Code: b9469d08 7100011f 540003ad 52800208 (f9400108) [ 2.384600] ---[ end trace 266d08dbf96ff143 ]--- [ 2.385171] Kernel panic - not syncing: Fatal exception in interrupt In this configuration arm64_get_bp_hardening_data() returns NULL. Add a check in kvm_get_hyp_vector(). Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/linux-arm-kernel/20220408120041.GB27685@willie-the-truck/ Fixes: 26129ea2953b ("KVM: arm64: Add templates for BHB mitigation sequences") Cc: stable@vger.kernel.org # 5.4.x Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm64/include/asm/kvm_mmu.h3
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/arm64/include/asm/kvm_mmu.h b/arch/arm64/include/asm/kvm_mmu.h
index 78d110667c0c..ffe0aad96b17 100644
--- a/arch/arm64/include/asm/kvm_mmu.h
+++ b/arch/arm64/include/asm/kvm_mmu.h
@@ -479,7 +479,8 @@ static inline void *kvm_get_hyp_vector(void)
int slot = -1;
if ((cpus_have_const_cap(ARM64_HARDEN_BRANCH_PREDICTOR) ||
- cpus_have_const_cap(ARM64_SPECTRE_BHB)) && data->template_start) {
+ cpus_have_const_cap(ARM64_SPECTRE_BHB)) &&
+ data && data->template_start) {
vect = kern_hyp_va(kvm_ksym_ref(__bp_harden_hyp_vecs_start));
slot = data->hyp_vectors_slot;
}