kernel/linux.git/arch/s390, branch v7.2-rc6

Merge tag 's390-7.2-6' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2026-08-02T18:55:49+00:00

Pull s390 updates from Vasily Gorbik: - Fix PCI MMIO write syscall falsely reporting success for mappings not valid for MMIO when MIO is unavailable by returning -EFAULT - Fix CPRB parameter buffer overflows in zcrypt CCA AES cipher and ECC private key conversion by rejecting oversized key tokens - Fix buffer overreads and length underflow in pkey and zcrypt CCA token validation by checking length fields against actual buffer sizes - Fix out of bounds permission bitmap access in zcrypt EP11 admin CPRB filtering on custom device nodes by using AP_DOMAINS as the limit - Fix speculative permission bitmap reads in zcrypt CCA and EP11 admin CPRB handling by sanitizing user controlled domain indexes - Fix sensitive key material left in zcrypt CCA clear key import buffers by scrubbing CPRB and temporary buffers after use * tag 's390-7.2-6' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/zcrypt: Fix missing mem scrub at clear key import in cca_clr2cipherkey() s390/zcrypt: Close speculative mem read possibility s390/zcrypt: Fix wrong domain value verification with EP11 CPRBs s390/zcrypt: Fix buffer over-read in cca_cipher2protkey s390/zcrypt: Validate length for CCA ECC private key requests s390/zcrypt: Validate length for CCA AES cipher key requests s390/pci: Fix s390_pci_mmio_write syscall error return without MIO

s390/pci: Fix s390_pci_mmio_write syscall error return without MIO

2026-07-31T11:31:19+00:00

On a machine without PCI memory-I/O (MIO) support or when running with pci=nomio the s390 specific PCI MMIO write syscall checks if the MMIO cookie is above ZPCI_IOMAP_ADDR_BASE as a sanity check before even trying to perform the MMIO. If this check fails the return value was left unchanged and thus 0 from prior operations falsely indicating success. This could potentially confuse user-space into falsely believing the MMIO, on a mapping not valid for MMIO was successful. Fix this by setting the return value to -EFAULT prior to the check following the same pattern as elsewhere in the same function. Cc: stable@vger.kernel.org Reviewed-by: Julian Ruess Reviewed-by: Farhan Ali Fixes: a67a88b0b8de ("s390/pci: remove races against pte updates") Signed-off-by: Niklas Schnelle Signed-off-by: Vasily Gorbik

Merge tag 'kvm-s390-master-7.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

2026-07-28T15:43:18+00:00

KVM: s390: Fixes for 7.2 - several fixes for PCI passthru in s390 kvm - fix a 7.2-rc regression in the adapter interrupt mapping code

KVM: s390: Fall back to short-term pinning in MAP ioctl

2026-07-27T07:23:53+00:00

FOLL_LONGTERM pinning fails for some memory types, such as file-backed guest memory. As a result, kvm_s390_adapter_map() returns -EINVAL and irqfd adapter registration fails even though interrupt delivery could still work via the existing non-atomic path. When FOLL_LONGTERM pinning fails, verify that the page is accessible using a short-term pin instead. If the short-term pin succeeds, unpin the page and add a map entry with pinned=false to preserve MAP/UNMAP symmetry. The non-atomic irqfd path already performs short-term pinning for interrupt delivery, so this restores the previous behavior for memory that cannot be pinned long-term. get_map_info() is updated to return NULL for unpinned entries so that the atomic irqfd fast path falls back to the non-atomic path. kvm_s390_adapter_unmap() and kvm_s390_unmap_all_adapters() skip dirty marking and unpin for unpinned entries. Update Documentation/virt/kvm/devices/s390_flic.rst to reflect the new MAP/UNMAP behavior. Fixes: c9a568838086 ("KVM: s390: Add map/unmap ioctl and clean mappings post-guest") Signed-off-by: Jaehoon Kim Reviewed-by: Douglas Freimuth Reviewed-by: Matthew Rosato Signed-off-by: Christian Borntraeger

KVM: s390: pci: Validate AIBV and AISB before pinning guest pages

2026-07-24T09:26:54+00:00

The AIBV holds one bit per MSI-X vector for a given function. The size of the bit vector is derived from the NOI and the AIBVO. If the size of the AIBV exceeds a single page boundary, then reject the request as we cannot safely pin the guest AIBV. Similarly reject the request if the AISB address is not 8-byte aligned as the architecture requires doubleword alignment for the summary bit address. Since the AISBO can address up to 64 bits, the size of the AISB can only be 8 bytes for the function. This also ensures the AISB doesn't exceed a single page boundary. Fixes: 3c5a1b6f0a18 ("KVM: s390: pci: provide routines for enabling/disabling interrupt forwarding") Cc: stable@vger.kernel.org Reviewed-by: Christian Borntraeger Reviewed-by: Matthew Rosato Signed-off-by: Farhan Ali Tested-by: Matthew Rosato Signed-off-by: Christian Borntraeger

KVM: s390: pci: Fix resource leak on IRQ registration failure

2026-07-24T09:26:54+00:00

Currently if kvm_zpci_set_airq() fails, kvm_s390_pci_aif_enable() returns the error code but doesn't do any resource cleanup thus leaking resources. Fix this by cleaning up all the resources such as the GAITE, AIBV, AISB and unpinning any pinned pages. While at it, remove dead code that stored FIB values that were never referenced. As part of the cleanup, we are also holding the aift_lock a bit longer, as we hold the lock while executing the MPCIFC instruction. Though this is not strictly necessary, it means we don't have to drop and re-acquire in the error case. Fixes: 3c5a1b6f0a18 ("KVM: s390: pci: provide routines for enabling/disabling interrupt forwarding") Cc: stable@vger.kernel.org Reviewed-by: Matthew Rosato Reviewed-by: Christian Borntraeger Signed-off-by: Farhan Ali Tested-by: Matthew Rosato Signed-off-by: Christian Borntraeger

KVM: s390: pci: Fix NULL dereference on AIBV allocation failure

2026-07-24T09:26:54+00:00

The airq_iv_create() can return NULL on failure, but the return value was never checked. If it fails, zdev->aibv will be NULL and fail when dereferenced in kvm_zpci_set_airq(). Add a NULL check and free the previously allocated AISB bit and zdev->aisb on failure. Fixes: 3c5a1b6f0a18 ("KVM: s390: pci: provide routines for enabling/disabling interrupt forwarding") Cc: stable@vger.kernel.org Reviewed-by: Christian Borntraeger Reviewed-by: Matthew Rosato Signed-off-by: Farhan Ali Tested-by: Matthew Rosato Signed-off-by: Christian Borntraeger

KVM: s390: pci: Fix missing error codes and memory unaccounting

2026-07-24T09:26:53+00:00

In kvm_s390_pci_aif_enable() two error paths failed to set an error code, causing the function to return 0 on failure. It also failed to rollback memory accounting on failure. Fix both by propagating an error code on failure and calling unaccount_mem() in the cleanup path. Fixes: 3c5a1b6f0a18 ("KVM: s390: pci: provide routines for enabling/disabling interrupt forwarding") Cc: stable@vger.kernel.org Reviewed-by: Christian Borntraeger Reviewed-by: Matthew Rosato Signed-off-by: Farhan Ali Tested-by: Matthew Rosato Signed-off-by: Christian Borntraeger

KVM: s390: pci: Fix memory accounting for pinned/unpinned pages

2026-07-24T09:26:53+00:00

The account_mem() and unaccount_mem() functions call get_uid() which increments the reference count of struct user_struct on every invocation. But we don't decrement the count by calling free_uid(). It also accounted/unaccounted the pages against the current->mm. But its possible the unaccount_mem() can be called from a different process context than the one that originally pinned the pages. Let's fix this by storing the pinning process user_struct and mm_struct when accounting for pinned pages, and subsequently free these resources when the pages are unpinned. Fixes: 3c5a1b6f0a18 ("KVM: s390: pci: provide routines for enabling/disabling interrupt forwarding") Cc: stable@vger.kernel.org Reviewed-by: Christian Borntraeger Reviewed-by: Matthew Rosato Signed-off-by: Farhan Ali Tested-by: Matthew Rosato [borntraeger@linux.ibm.com: Fixed whitespace] Signed-off-by: Christian Borntraeger

KVM: s390: pci: Reject adapter interrupt forwarding if already enabled

2026-07-24T09:26:53+00:00

The MPCIFC instruction doesn't allow registering adapter interrupts without first unregistering. So reject any request to enable interrupt forwarding if its already enabled for the zPCI device. This also fixes overwriting and thus leaking resources when the ioctl is called multiple times for the same device. Fixes: 3c5a1b6f0a18 ("KVM: s390: pci: provide routines for enabling/disabling interrupt forwarding") Cc: stable@vger.kernel.org Reviewed-by: Christian Borntraeger Reviewed-by: Matthew Rosato Signed-off-by: Farhan Ali Tested-by: Matthew Rosato Signed-off-by: Christian Borntraeger