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authorJean-Philippe Brucker <jean-philippe@linaro.org>2024-04-19 18:07:24 +0200
committerChristian Borntraeger <borntraeger@linux.ibm.com>2024-05-02 09:41:38 +0200
commit175f2f5bcdfce9e728f1ff956a50f28824d28791 (patch)
tree99bae9412e3849f89cab362fe0cbd5618dafeebd
parentMerge tag 'kvmarm-fixes-6.9-2' of git://git.kernel.org/pub/scm/linux/kernel/g... (diff)
downloadlinux-175f2f5bcdfce9e728f1ff956a50f28824d28791.tar.xz
linux-175f2f5bcdfce9e728f1ff956a50f28824d28791.zip
KVM: s390: Check kvm pointer when testing KVM_CAP_S390_HPAGE_1M
KVM allows issuing the KVM_CHECK_EXTENSION ioctl either on the /dev/kvm fd or the VM fd. In the first case, kvm_vm_ioctl_check_extension() is called with kvm==NULL. Ensure we don't dereference the pointer in that case. Fixes: 40ebdb8e59df ("KVM: s390: Make huge pages unavailable in ucontrol VMs") Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Message-ID: <20240419160723.320910-2-jean-philippe@linaro.org> Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
-rw-r--r--arch/s390/kvm/kvm-s390.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 5147b943a864..7721eb522f43 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -587,7 +587,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
break;
case KVM_CAP_S390_HPAGE_1M:
r = 0;
- if (hpage && !kvm_is_ucontrol(kvm))
+ if (hpage && !(kvm && kvm_is_ucontrol(kvm)))
r = 1;
break;
case KVM_CAP_S390_MEM_OP: