CVE-2026-53289

Published Jun 26, 2026

Last updated a month ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: ice: fix NULL pointer dereference in ice_reset_all_vfs() ice_reset_all_vfs() ignores the return value of ice_vf_rebuild_vsi(). When the VSI rebuild fails (e.g. during NVM firmware update via nvmupdate64e), ice_vsi_rebuild() tears down the VSI on its error path, leaving txq_map and rxq_map as NULL. The subsequent unconditional call to ice_vf_post_vsi_rebuild() leads to a NULL pointer dereference in ice_ena_vf_q_mappings() when it accesses vsi->txq_map[0]. The single-VF reset path in ice_reset_vf() already handles this correctly by checking the return value of ice_vf_reconfig_vsi() and skipping ice_vf_post_vsi_rebuild() on failure. Apply the same pattern to ice_reset_all_vfs(): check the return value of ice_vf_rebuild_vsi() and skip ice_vf_post_vsi_rebuild() and ice_eswitch_attach_vf() on failure. The VF is left safely disabled (ICE_VF_STATE_INIT not set, VFGEN_RSTAT not set to VFACTIVE) and can be recovered via a VFLR triggered by a PCI reset of the VF (sysfs reset or driver rebind). Note that this patch does not prevent the VF VSI rebuild from failing during NVM update — the underlying cause is firmware being in a transitional state while the EMP reset is processed, which can cause Admin Queue commands (ice_add_vsi, ice_cfg_vsi_lan) to fail. This patch only prevents the subsequent NULL pointer dereference that crashes the kernel when the rebuild does fail. crash> bt PID: 50795 TASK: ff34c9ee708dc680 CPU: 1 COMMAND: "kworker/u512:5" #0 [ff72159bcfe5bb50] machine_kexec at ffffffffaa8850ee #1 [ff72159bcfe5bba8] __crash_kexec at ffffffffaaa15fba #2 [ff72159bcfe5bc68] crash_kexec at ffffffffaaa16540 #3 [ff72159bcfe5bc70] oops_end at ffffffffaa837eda #4 [ff72159bcfe5bc90] page_fault_oops at ffffffffaa893997 #5 [ff72159bcfe5bce8] exc_page_fault at ffffffffab528595 #6 [ff72159bcfe5bd10] asm_exc_page_fault at ffffffffab600bb2 [exception RIP: ice_ena_vf_q_mappings+0x79] RIP: ffffffffc0a85b29 RSP: ff72159bcfe5bdc8 RFLAGS: 00010206 RAX: 00000000000f0000 RBX: ff34c9efc9c00000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000010 RDI: ff34c9efc9c00000 RBP: ff34c9efc27d4828 R8: 0000000000000093 R9: 0000000000000040 R10: ff34c9efc27d4828 R11: 0000000000000040 R12: 0000000000100000 R13: 0000000000000010 R14: R15: ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #7 [ff72159bcfe5bdf8] ice_sriov_post_vsi_rebuild at ffffffffc0a85e2e [ice] #8 [ff72159bcfe5be08] ice_reset_all_vfs at ffffffffc0a920b4 [ice] #9 [ff72159bcfe5be48] ice_service_task at ffffffffc0a31519 [ice] #10 [ff72159bcfe5be88] process_one_work at ffffffffaa93dca4 #11 [ff72159bcfe5bec8] worker_thread at ffffffffaa93e9de #12 [ff72159bcfe5bf18] kthread at ffffffffaa946663 #13 [ff72159bcfe5bf50] ret_from_fork at ffffffffaa8086b9 The panic occurs attempting to dereference the NULL pointer in RDX at ice_sriov.c:294, which loads vsi->txq_map (offset 0x4b8 in ice_vsi). The faulting VSI is an allocated slab object but not fully initialized after a failed ice_vsi_rebuild(): crash> struct ice_vsi 0xff34c9efc27d4828 netdev = 0x0, rx_rings = 0x0, tx_rings = 0x0, q_vectors = 0x0, txq_map = 0x0, rxq_map = 0x0, alloc_txq = 0x10, num_txq = 0x10, alloc_rxq = 0x10, num_rxq = 0x10, The nvmupdate64e process was performing NVM firmware update: crash> bt 0xff34c9edd1a30000 PID: 49858 TASK: ff34c9edd1a30000 CPU: 1 COMMAND: "nvmupdate64e" #0 [ff72159bcd617618] __schedule at ffffffffab5333f8 #4 [ff72159bcd617750] ice_sq_send_cmd at ffffffffc0a35347 [ice] #5 [ff72159bcd6177a8] ice_sq_send_cmd_retry at ffffffffc0a35b47 [ice] #6 [ff72159bcd617810] ice_aq_send_cmd at ffffffffc0a38018 [ice] #7 [ff72159bcd617848] ice_aq_read_nvm at ffffffffc0a40254 [ice] #8 ---truncated---
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Analyzed
Products
linux_kernel

Risk scores

CVSS 3.1

Type
Primary
Base score
5.5
Impact score
3.6
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Severity
MEDIUM

Weaknesses

nvd@nist.gov
CWE-476

Social media

Hype score
Not currently trending

Configurations

  1. In the Linux kernel, the following vulnerability has been resolved: KVM: x86/mmu: Ensure hugepage is in by slot before checking max mapping level When recovering hugepages in the shadow MMU, verify that the base gfn of the shadow page is actually contained within the target memslot, *before* querying the max mapping level given the shadow page's gfn. Failure to pre-check the validity of the gfn can lead to an out-of-bounds access to the slot's lpage_info (which typically manifests as a host #PF because the lpage_info is vmalloc'd) if the guest creates a hugepage mapping (in its PTEs) that extends "below" the bounds of a memslot. When faulting in memory for a guest, and the size of the guest mapping is greater than KVM's (current) max mapping, then KVM will create a "direct" shadow page (direct in that there are no gPTEs to shadow, and so the target gfn is a direct calculation given the base gfn of the shadow page). The hugepage recovery flow looks for such direct shadow pages, as forcing 4KiB mappings when dirty logging generates the guest > host mapping size case. When the 4KiB restriction is lifted, then KVM can replace the shadow page with a hugepage. But if KVM originally used a smaller mapping than the guest because the range of memory covered by the guest hugepage exceeds the bounds of a memslot, then KVM will link a direct shadow page with a gfn that is outside the bounds of the memslot being used to fault in memory. The rmap entry added for the leaf mapping is correct and within bounds, but the gfn of the leaf SPTE's parent shadow page will be out of bounds. BUG: unable to handle page fault for address: ffffc90000806ffc #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 100000067 P4D 100000067 PUD 1002a7067 PMD 10612f067 PTE 0 Oops: Oops: 0000 [#1] SMP CPU: 13 UID: 1000 PID: 757 Comm: mmu_stress_test Not tainted 7.1.0-rc1-48ce1e26eace-x86_pir_to_irr_comments-vm #341 PREEMPT Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:kvm_mmu_max_mapping_level+0x79/0x2b0 [kvm] Call Trace: <TASK> kvm_mmu_recover_huge_pages+0x21b/0x320 [kvm] kvm_set_memslot+0x1ee/0x590 [kvm] kvm_set_memory_region.part.0+0x3a1/0x4d0 [kvm] kvm_vm_ioctl+0x9bf/0x15d0 [kvm] __x64_sys_ioctl+0x8a/0xd0 do_syscall_64+0xb7/0xbb0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x7f21c0f1a9bf </TASK> Don't bother pre-checking the bounds of the potential hugepage, i.e. don't check that e.g. sp->gfn + KVM_PAGES_PER_HPAGE(sp->role.level + 1) is also within the memslot, as the checks performed by kvm_mmu_max_mapping_level() are a superset of the basic bounds checks. I.e. pre-checking the full range would be a dubious micro-optimization.CVE-2026-63807
  2. In the Linux kernel, the following vulnerability has been resolved: KVM: Replace guest-triggerable BUG_ON() in ioeventfd datamatch with get_unaligned() Drop a BUG_ON() that has been reachable since it was first added, way back in 2009, and instead use get_unaligned() to perform potentially-unaligned accesses. For a given store, KVM x86's emulator tracks the entire value in the destination operand, x86_emulate_ctxt.dst. If the destination is memory, and the target splits multiple pages and/or is emulated MMIO, then KVM handles each fragment independently. E.g. on a page split starting at page offset 0xffc, KVM writes 4 bytes to the first page, then the remaining bytes to the second page, using ctxt->dst as the source for both (with appropriate offsets). If the destination splits a page *and* hits emulated MMIO on the second page, then KVM will complete the write to the first page, then emulate the MMIO access to the second page. If there is a datamatch-enabled ioeventfd at offset 0 of the second page, then KVM will process the remainder of the store as a potential ioeventfd signal. Putting it all together, if the guest emits a store that splits a page starting at page offset N, and the second page has a datamatch-enabled ioeventfd at offset 0, then KVM will check for datamatch using &dst.valptr[N] as the source. Due to dst (and thus dst.valptr) being 32-byte aligned, if N is not aligned to @len, the BUG_ON() fires. E.g. with a 16-byte store at page offset 0xffc, to an ioeventfd of len 8, all initial checks in ioeventfd_in_range() will succeed, and the BUG_ON() fires due to @val being 4-byte aligned, but not 8-byte aligned. ------------[ cut here ]------------ kernel BUG at arch/x86/kvm/../../../virt/kvm/eventfd.c:783! Oops: invalid opcode: 0000 [#1] SMP CPU: 0 UID: 1000 PID: 615 Comm: repro Not tainted 7.1.0-rc2-ff238429d1ea #365 PREEMPT Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:ioeventfd_write+0x6c/0x70 [kvm] Call Trace: <TASK> __kvm_io_bus_write+0x85/0xb0 [kvm] kvm_io_bus_write+0x53/0x80 [kvm] vcpu_mmio_write+0x66/0xf0 [kvm] emulator_read_write_onepage+0x12a/0x540 [kvm] emulator_read_write+0x109/0x2b0 [kvm] x86_emulate_insn+0x4f8/0xfb0 [kvm] x86_emulate_instruction+0x181/0x790 [kvm] kvm_mmu_page_fault+0x313/0x630 [kvm] vmx_handle_exit+0x18a/0x590 [kvm_intel] kvm_arch_vcpu_ioctl_run+0xc81/0x1c90 [kvm] kvm_vcpu_ioctl+0x2d5/0x970 [kvm] __x64_sys_ioctl+0x8a/0xd0 do_syscall_64+0xb7/0x890 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x7f19c931a9bf </TASK> Modules linked in: kvm_intel kvm irqbypass ---[ end trace 0000000000000000 ]--- In a perfect world, the fix would be to simply delete the BUG_ON(), as KVM x86 doesn't perform alignment checks on "normal" memory accesses at CPL0. Sadly, C99 ruins all the fun; while the x86 architecture plays nice, dereferencing an unaligned pointer directly is undefined behavior in C, e.g. triggers splats when running with CONFIG_UBSAN_ALIGNMENT=y.CVE-2026-63806
  3. In the Linux kernel, the following vulnerability has been resolved: hdlc_ppp: sync per-proto timers before freeing hdlc state Each PPP control protocol (LCP/IPCP/IPV6CP) embedded in struct ppp registers a timer via timer_setup(). That struct ppp is the hdlc->state allocation, which detach_hdlc_protocol() frees with kfree() in both teardown paths: unregister_hdlc_device() and the re-attach inside attach_hdlc_protocol(). The ppp proto never registered a .detach callback, so detach_hdlc_protocol() performs no timer synchronization before the kfree(). The only cancel, timer_delete(&proto->timer) in ppp_cp_event(), is partial (it does not wait for a running callback) and only runs on the ->CLOSED transition; ppp_stop()/ppp_close() do not sync either. A ppp_timer callback already executing (blocked on ppp->lock) survives the kfree and then dereferences proto->state / ppp->lock in freed memory, leading to a use-after-free. Fix this by adding a .detach helper that calls timer_shutdown_sync() on every per-proto timer. detach_hdlc_protocol() invokes proto->detach(dev) before kfree(hdlc->state), so timer_shutdown_sync() now runs on both free paths. timer_shutdown_sync() is used instead of timer_delete_sync() because the keepalive path re-arms the timer through add_timer()/mod_timer() and shutdown blocks any re-activation during teardown. Initialize the per-protocol timers in ppp_ioctl() when the protocol is attached, and remove the now-redundant timer_setup() from ppp_start(), so that the timers are initialized exactly once at attach time and ppp_timer_release() never operates on uninitialized timer_list structures. attach_hdlc_protocol() uses kmalloc() (not kzalloc), so struct ppp's protos[i].timer is uninitialized garbage until the first timer_setup(); without this init-at-attach, attaching the PPP protocol without ever bringing the device up would leave timer_shutdown_sync() operating on uninitialized memory in .detach. Moving the init out of ppp_start() (which only runs on NETDEV_UP) into the attach path makes the initialization unconditional and avoids initializing the same timer_list twice. This bug was found by static analysis.CVE-2026-63803