From: sashiko-bot@kernel.org
To: "Claudio Imbrenda" <imbrenda@linux.ibm.com>
Cc: "Heiko Carstens" <hca@linux.ibm.com>,
"Vasily Gorbik" <gor@linux.ibm.com>,
linux-s390@vger.kernel.org,
"Alexander Gordeev" <agordeev@linux.ibm.com>,
kvm@vger.kernel.org
Subject: Re: [PATCH v4 01/13] KVM: s390: Fix unlikely NULL gmap dereference
Date: Tue, 28 Jul 2026 17:27:18 +0000 [thread overview]
Message-ID: <20260728172719.136481F000E9@smtp.kernel.org> (raw)
In-Reply-To: <20260728170708.294400-2-imbrenda@linux.ibm.com>
> When creating a new vCPU, kvm_vm_ioctl_create_vcpu() will call
> kvm_arch_vcpu_postcreate() after the file descriptor for the new vCPU
> has been created. The new file descriptor has not been returned yet,
> but a malicious userspace program could try to guess it.
>
> If a malicious userspace program manages to start the newly created vCPU
> before kvm_arch_vcpu_postcreate() is called, __vcpu_run() will try to
> dereference vcpu->arch.gmap and trigger a NULL pointer dereference.
>
> Fix this by adding a new field to struct kvm_vcpu_arch to keep track of
> the initialization status of the vCPU. Refuse to run a vCPU that is not
> fully initialized.
>
> Fixes: dafd032a15f8 ("KVM: s390: move vcpu specific initalization to a later point")
> Fixes: e38c884df921 ("KVM: s390: Switch to new gmap")
> Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Sashiko has reviewed this patch and found no issues. It looks great!
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260728170708.294400-1-imbrenda@linux.ibm.com?part=1
next prev parent reply other threads:[~2026-07-28 17:27 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-28 17:06 [PATCH v4 00/13] KVM: s390: Misc fixes Claudio Imbrenda
2026-07-28 17:06 ` [PATCH v4 01/13] KVM: s390: Fix unlikely NULL gmap dereference Claudio Imbrenda
2026-07-28 17:27 ` sashiko-bot [this message]
2026-07-28 17:06 ` [PATCH v4 02/13] KVM: s390: Fix leaking of PGM_ADDRESSING to userspace Claudio Imbrenda
2026-07-28 17:16 ` sashiko-bot
2026-07-28 17:06 ` [PATCH v4 03/13] KVM: s390: Fix race in __do_essa() Claudio Imbrenda
2026-07-28 17:21 ` sashiko-bot
2026-07-28 17:06 ` [PATCH v4 04/13] KVM: s390: cmma: Fix dirty tracking when removing memslot Claudio Imbrenda
2026-07-28 17:22 ` sashiko-bot
2026-07-28 17:07 ` [PATCH v4 05/13] KVM: s390: ucontrol: Add missing locking around gmap_remove_child() Claudio Imbrenda
2026-07-28 17:20 ` sashiko-bot
2026-07-28 17:07 ` [PATCH v4 06/13] KVM: s390: Fix overclearing ESCA in case of error Claudio Imbrenda
2026-07-28 17:27 ` sashiko-bot
2026-07-28 17:07 ` [PATCH v4 07/13] KVM: s390: Return -EINTR if a signal was pending while faulting-in Claudio Imbrenda
2026-07-28 17:32 ` sashiko-bot
2026-07-28 17:07 ` [PATCH v4 08/13] KVM: s390: Free the mmu cache when kvm_arch_vcpu_create() fails Claudio Imbrenda
2026-07-28 17:27 ` sashiko-bot
2026-07-28 17:07 ` [PATCH v4 09/13] KVM: s390: Fix ordering when adding to SCA Claudio Imbrenda
2026-07-28 17:15 ` sashiko-bot
2026-07-28 17:07 ` [PATCH v4 10/13] KVM: s390: Fix cleanup in kvm_s390_pv_create_cpu() Claudio Imbrenda
2026-07-28 17:14 ` sashiko-bot
2026-07-28 17:07 ` [PATCH v4 11/13] KVM: s390: Fix kvm_arch_commit_memory_region() when low on memory Claudio Imbrenda
2026-07-28 17:25 ` sashiko-bot
2026-07-28 17:07 ` [PATCH v4 12/13] KVM: s390: Fix kvm_s390_vcpu_unsetup_cmma() Claudio Imbrenda
2026-07-28 17:24 ` sashiko-bot
2026-07-28 17:07 ` [PATCH v4 13/13] KVM: s390: Fix sca_clear_ext_call() for UCONTROL Claudio Imbrenda
2026-07-28 17:39 ` sashiko-bot
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