linux-kernel - [PATCH 0/2] KVM: x86: never write to memory from kvm_vcpu_check

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20220427173758.517087-1-pbonzini@redhat.com>
Date:   Wed, 27 Apr 2022 13:37:55 -0400
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     mlevitsk@...hat.com, seanjc@...gle.com
Subject: [PATCH 0/2] KVM: x86: never write to memory from kvm_vcpu_check_block

Maxim reported the following backtrace:

[ 1355.807187]  kvm_vcpu_map+0x159/0x190 [kvm]
[ 1355.807628]  nested_svm_vmexit+0x4c/0x7f0 [kvm_amd]
[ 1355.808036]  ? kvm_vcpu_block+0x54/0xa0 [kvm]
[ 1355.808450]  svm_check_nested_events+0x97/0x390 [kvm_amd]
[ 1355.808920]  kvm_check_nested_events+0x1c/0x40 [kvm] 
[ 1355.809396]  kvm_arch_vcpu_runnable+0x4e/0x190 [kvm]
[ 1355.809892]  kvm_vcpu_check_block+0x4f/0x100 [kvm]
[ 1355.811259]  kvm_vcpu_block+0x6b/0xa0 [kvm] 

due to kmap being called in non-sleepable (!TASK_RUNNING) context.
Fix it by extending kvm_x86_ops->nested_ops.hv_timer_pending and
getting rid of one annoying instance of kvm_check_nested_events.

Paolo