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| author | Junrui Luo <moonafterrain@outlook.com> | 2026-04-15 12:26:55 +0300 |
|---|---|---|
| committer | Christian Borntraeger <borntraeger@linux.ibm.com> | 2026-04-17 14:12:07 +0300 |
| commit | 16d990a15491cf76cd6eef0846e1b4100e63261a (patch) | |
| tree | 09c92145631042af77127ef4f56ca1cae7ff87e1 | |
| parent | 028ef9c96e96197026887c0f092424679298aae8 (diff) | |
| download | linux-16d990a15491cf76cd6eef0846e1b4100e63261a.tar.xz | |
KVM: s390: pci: fix GAIT table indexing due to double-scaling pointer arithmetic
kvm_s390_pci_aif_enable(), kvm_s390_pci_aif_disable(), and
aen_host_forward() index the GAIT by manually multiplying the index
with sizeof(struct zpci_gaite).
Since aift->gait is already a struct zpci_gaite pointer, this
double-scales the offset, accessing element aisb*16 instead of aisb.
This causes out-of-bounds accesses when aisb >= 32 (with
ZPCI_NR_DEVICES=512)
Fix by removing the erroneous sizeof multiplication.
Fixes: 3c5a1b6f0a18 ("KVM: s390: pci: provide routines for enabling/disabling interrupt forwarding")
Fixes: 73f91b004321 ("KVM: s390: pci: enable host forwarding of Adapter Event Notifications")
Reported-by: Yuhao Jiang <danisjiang@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Junrui Luo <moonafterrain@outlook.com>
Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com>
| -rw-r--r-- | arch/s390/kvm/interrupt.c | 3 | ||||
| -rw-r--r-- | arch/s390/kvm/pci.c | 6 |
2 files changed, 3 insertions, 6 deletions
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c index 7cb8ce833b62..f48f25c7dc8f 100644 --- a/arch/s390/kvm/interrupt.c +++ b/arch/s390/kvm/interrupt.c @@ -3307,8 +3307,7 @@ static void aen_host_forward(unsigned long si) struct zpci_gaite *gaite; struct kvm *kvm; - gaite = (struct zpci_gaite *)aift->gait + - (si * sizeof(struct zpci_gaite)); + gaite = aift->gait + si; if (gaite->count == 0) return; if (gaite->aisb != 0) diff --git a/arch/s390/kvm/pci.c b/arch/s390/kvm/pci.c index 86d93e8dddae..eed45af1a92d 100644 --- a/arch/s390/kvm/pci.c +++ b/arch/s390/kvm/pci.c @@ -290,8 +290,7 @@ static int kvm_s390_pci_aif_enable(struct zpci_dev *zdev, struct zpci_fib *fib, phys_to_virt(fib->fmt0.aibv)); spin_lock_irq(&aift->gait_lock); - gaite = (struct zpci_gaite *)aift->gait + (zdev->aisb * - sizeof(struct zpci_gaite)); + gaite = aift->gait + zdev->aisb; /* If assist not requested, host will get all alerts */ if (assist) @@ -357,8 +356,7 @@ static int kvm_s390_pci_aif_disable(struct zpci_dev *zdev, bool force) if (zdev->kzdev->fib.fmt0.aibv == 0) goto out; spin_lock_irq(&aift->gait_lock); - gaite = (struct zpci_gaite *)aift->gait + (zdev->aisb * - sizeof(struct zpci_gaite)); + gaite = aift->gait + zdev->aisb; isc = gaite->gisc; gaite->count--; if (gaite->count == 0) { |