In the Linux kernel, the following vulnerability has been resolved: KVM: SEV: Protect *all* of sev_mem_enc_register_region() with kvm->lock Take and hold kvm->lock for before checking sev_guest() in sev_mem_enc_register_region(), as sev_guest() isn't stable unless kvm->lock is held (or KVM can guarantee KVM_SEV_INIT{2} has completed and can't rollack state). If KVM_SEV_INIT{2} fails, KVM can end up trying to add to a not-yet-initialized sev->regions_list, e.g. triggering a #GP Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 110 UID: 0 PID: 72717 Comm: syz.15.11462 Tainted: G U W O 6.16.0-smp-DEV #1 NONE Tainted: [U]=USER, [W]=WARN, [O]=OOT_MODULE Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 12.52.0-0 10/28/2024 RIP: 0010:sev_mem_enc_register_region+0x3f0/0x4f0 ../include/linux/list.h:83 Code: <41> 80 3c 04 00 74 08 4c 89 ff e8 f1 c7 a2 00 49 39 ed 0f 84 c6 00 RSP: 0018:ffff88838647fbb8 EFLAGS: 00010256 RAX: dffffc0000000000 RBX: 1ffff92015cf1e0b RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000001000 RDI: ffff888367870000 RBP: ffffc900ae78f050 R08: ffffea000d9e0007 R09: 1ffffd4001b3c000 R10: dffffc0000000000 R11: fffff94001b3c001 R12: 0000000000000000 R13: ffff8982ab0bde00 R14: ffffc900ae78f058 R15: 0000000000000000 FS: 00007f34e9dc66c0(0000) GS:ffff89ee64d33000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe180adef98 CR3: 000000047210e000 CR4: 0000000000350ef0 Call Trace: <TASK> kvm_arch_vm_ioctl+0xa72/0x1240 ../arch/x86/kvm/x86.c:7371 kvm_vm_ioctl+0x649/0x990 ../virt/kvm/kvm_main.c:5363 __se_sys_ioctl+0x101/0x170 ../fs/ioctl.c:51 do_syscall_x64 ../arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x6f/0x1f0 ../arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f34e9f7e9a9 Code: <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f34e9dc6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f34ea1a6080 RCX: 00007f34e9f7e9a9 RDX: 0000200000000280 RSI: 000000008010aebb RDI: 0000000000000007 RBP: 00007f34ea000d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f34ea1a6080 R15: 00007ffce77197a8 </TASK> with a syzlang reproducer that looks like: syz_kvm_add_vcpu$x86(0x0, &(0x7f0000000040)={0x0, &(0x7f0000000180)=ANY=[], 0x70}) (async) syz_kvm_add_vcpu$x86(0x0, &(0x7f0000000080)={0x0, &(0x7f0000000180)=ANY=[@ANYBLOB="..."], 0x4f}) (async) r0 = openat$kvm(0xffffffffffffff9c, &(0x7f0000000200), 0x0, 0x0) r1 = ioctl$KVM_CREATE_VM(r0, 0xae01, 0x0) r2 = openat$kvm(0xffffffffffffff9c, &(0x7f0000000240), 0x0, 0x0) r3 = ioctl$KVM_CREATE_VM(r2, 0xae01, 0x0) ioctl$KVM_SET_CLOCK(r3, 0xc008aeba, &(0x7f0000000040)={0x1, 0x8, 0x0, 0x5625e9b0}) (async) ioctl$KVM_SET_PIT2(r3, 0x8010aebb, &(0x7f0000000280)={[...], 0x5}) (async) ioctl$KVM_SET_PIT2(r1, 0x4070aea0, 0x0) (async) r4 = ioctl$KVM_CREATE_VM(0xffffffffffffffff, 0xae01, 0x0) openat$kvm(0xffffffffffffff9c, 0x0, 0x0, 0x0) (async) ioctl$KVM_SET_USER_MEMORY_REGION(r4, 0x4020ae46, &(0x7f0000000400)={0x0, 0x0, 0x0, 0x2000, &(0x7f0000001000/0x2000)=nil}) (async) r5 = ioctl$KVM_CREATE_VCPU(r4, 0xae41, 0x2) close(r0) (async) openat$kvm(0xffffffffffffff9c, &(0x7f0000000000), 0x8000, 0x0) (async) ioctl$KVM_SET_GUEST_DEBUG(r5, 0x4048ae9b, &(0x7f0000000300)={0x4376ea830d46549b, 0x0, [0x46, 0x0, 0x0, 0x0, 0x0, 0x1000]}) (async) ioctl$KVM_RUN(r5, 0xae80, 0x0) Opportunistically use guard() to avoid having to define a new error label and goto usage.

It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2026-1693 advisory.

    In the Linux kernel, the following vulnerability has been resolved:

    af_unix: Give up GC if MSG_PEEK intervened. (CVE-2026-23394)

    In the Linux kernel, the following vulnerability has been resolved:

    ipv6: add NULL checks for idev in SRv6 paths (CVE-2026-23442)

    In the Linux kernel, the following vulnerability has been resolved:

    netfilter: ipset: drop logically empty buckets in mtype_del (CVE-2026-31418)

    In the Linux kernel, the following vulnerability has been resolved:

    net: skb: fix cross-cache free of KFENCE-allocated skb head (CVE-2026-31429)

    In the Linux kernel, the following vulnerability has been resolved:

    X.509: Fix out-of-bounds access when parsing extensions (CVE-2026-31430)

    In the Linux kernel, the following vulnerability has been resolved:

    ipv4: nexthop: allocate skb dynamically in rtm_get_nexthop() (CVE-2026-31531)

    In the Linux kernel, the following vulnerability has been resolved:

    can: raw: fix ro->uniq use-after-free in raw_rcv() (CVE-2026-31532)

    In the Linux kernel, the following vulnerability has been resolved:

    net/tls: fix use-after-free in -EBUSY error path of tls_do_encryption (CVE-2026-31533)

    In the Linux kernel, the following vulnerability has been resolved:

    mm/userfaultfd: fix hugetlb fault mutex hash calculation (CVE-2026-31575)

    In the Linux kernel, the following vulnerability has been resolved:

    wireguard: device: use exit_rtnl callback instead of manual rtnl_lock in pre_exit (CVE-2026-31579)

    In the Linux kernel, the following vulnerability has been resolved:

    bcache: fix cached_dev.sb_bio use-after-free and crash (CVE-2026-31580)

    In the Linux kernel, the following vulnerability has been resolved:

    mm: blk-cgroup: fix use-after-free in cgwb_release_workfn() (CVE-2026-31586)

    In the Linux kernel, the following vulnerability has been resolved:

    KVM: x86: Use scratch field in MMIO fragment to hold small write values (CVE-2026-31588)

    In the Linux kernel, the following vulnerability has been resolved:

    KVM: SEV: Lock all vCPUs when synchronzing VMSAs for SNP launch finish (CVE-2026-31591)

    In the Linux kernel, the following vulnerability has been resolved:

    KVM: SEV: Protect *all* of sev_mem_enc_register_region() with kvm->lock (CVE-2026-31592)

    In the Linux kernel, the following vulnerability has been resolved:

    KVM: SEV: Reject attempts to sync VMSA of an already-launched/encrypted vCPU (CVE-2026-31593)

    In the Linux kernel, the following vulnerability has been resolved:

    arm64: mm: Handle invalid large leaf mappings correctly (CVE-2026-31600)

    In the Linux kernel, the following vulnerability has been resolved:

    usbip: validate number_of_packets in usbip_pack_ret_submit() (CVE-2026-31607)

    In the Linux kernel, the following vulnerability has been resolved:

    smb: client: fix OOB reads parsing symlink error response (CVE-2026-31613)

    In the Linux kernel, the following vulnerability has been resolved:

    smb: client: fix off-by-8 bounds check in check_wsl_eas() (CVE-2026-31614)

    In the Linux kernel, the following vulnerability has been resolved:

    HID: core: clamp report_size in s32ton() to avoid undefined shift (CVE-2026-31624)

    In the Linux kernel, the following vulnerability has been resolved:

    HID: alps: fix NULL pointer dereference in alps_raw_event() (CVE-2026-31625)

    In the Linux kernel, the following vulnerability has been resolved:

    x86/CPU: Fix FPDSS on Zen1 (CVE-2026-31628)

    In the Linux kernel, the following vulnerability has been resolved:

    rxrpc: fix reference count leak in rxrpc_server_keyring() (CVE-2026-31634)

    In the Linux kernel, the following vulnerability has been resolved:

    rxrpc: reject undecryptable rxkad response tickets (CVE-2026-31637)

    In the Linux kernel, the following vulnerability has been resolved:

    mm: filemap: fix nr_pages calculation overflow in filemap_map_pages() (CVE-2026-31648)

    In the Linux kernel, the following vulnerability has been resolved:

    mm/damon/sysfs: dealloc repeat_call_control if damon_call() fails (CVE-2026-31653)

    In the Linux kernel, the following vulnerability has been resolved:

    drm/i915/gt: fix refcount underflow in intel_engine_park_heartbeat (CVE-2026-31656)

    In the Linux kernel, the following vulnerability has been resolved:

    tipc: fix bc_ackers underflow on duplicate GRP_ACK_MSG (CVE-2026-31662)

    In the Linux kernel, the following vulnerability has been resolved:

    xfrm: hold dev ref until after transport_finish NF_HOOK (CVE-2026-31663)

    In the Linux kernel, the following vulnerability has been resolved:

    xfrm: clear trailing padding in build_polexpire() (CVE-2026-31664)

    In the Linux kernel, the following vulnerability has been resolved:

    netfilter: nft_ct: fix use-after-free in timeout object destroy (CVE-2026-31665)

    In the Linux kernel, the following vulnerability has been resolved:

    btrfs: fix incorrect return value after changing leaf in lookup_extent_data_ref() (CVE-2026-31666)

    In the Linux kernel, the following vulnerability has been resolved:

    Input: uinput - fix circular locking dependency with ff-core (CVE-2026-31667)

    In the Linux kernel, the following vulnerability has been resolved:

    seg6: separate dst_cache for input and output paths in seg6 lwtunnel (CVE-2026-31668)

    In the Linux kernel, the following vulnerability has been resolved:

    mptcp: fix slab-use-after-free in __inet_lookup_established (CVE-2026-31669)

    In the Linux kernel, the following vulnerability has been resolved:

    xfrm_user: fix info leak in build_report() (CVE-2026-31671)

    In the Linux kernel, the following vulnerability has been resolved:

    af_unix: read UNIX_DIAG_VFS data under unix_state_lock (CVE-2026-31673)

    In the Linux kernel, the following vulnerability has been resolved:

    netfilter: xt_multiport: validate range encoding in checkentry (CVE-2026-31681)

    In the Linux kernel, the following vulnerability has been resolved:

    net: sched: act_csum: validate nested VLAN headers (CVE-2026-31684)

    In the Linux kernel, the following vulnerability has been resolved:

    netfilter: ip6t_eui64: reject invalid MAC header for all packets (CVE-2026-31685)

    In the Linux kernel, the following vulnerability has been resolved:

    EDAC/mc: Fix error path ordering in edac_mc_alloc() (CVE-2026-31689)

    In the Linux kernel, the following vulnerability has been resolved:

    igb: remove napi_synchronize() in igb_down() (CVE-2026-31691)

    In the Linux kernel, the following vulnerability has been resolved:

    rtnetlink: add missing netlink_ns_capable() check for peer netns (CVE-2026-31692)

    In the Linux kernel, the following vulnerability has been resolved:

    fuse: reject oversized dirents in page cache (CVE-2026-31694)

    In the Linux kernel, the following vulnerability has been resolved:

    net/packet: fix TOCTOU race on mmap'd vnet_hdr in tpacket_snd() (CVE-2026-31700)

    In the Linux kernel, the following vulnerability has been resolved:

    writeback: Fix use after free in inode_switch_wbs_work_fn() (CVE-2026-31703)

    In the Linux kernel, the following vulnerability has been resolved:

    smb: client: fix OOB read in smb2_ioctl_query_info QUERY_INFO path (CVE-2026-31708)

    In the Linux kernel, the following vulnerability has been resolved:

    fuse: abort on fatal signal during sync init (CVE-2026-31713)

    In the Linux kernel, the following vulnerability has been resolved:

    fs/ntfs3: validate rec->used in journal-replay file record check (CVE-2026-31716)

    In the Linux kernel, the following vulnerability has been resolved:

    crypto: krb5enc - fix async decrypt skipping hash verification (CVE-2026-31719)

    In the Linux kernel, the following vulnerability has been resolved:

    dcache: Limit the minimal number of bucket to two (CVE-2026-43071)

    In the Linux kernel, the following vulnerability has been resolved:

    x86-64: rename misleadingly named '__copy_user_nocache()' function (CVE-2026-43073)

    In the Linux kernel, the following vulnerability has been resolved:

    eventpoll: defer struct eventpoll free to RCU grace period (CVE-2026-43074)

    In the Linux kernel, the following vulnerability has been resolved:

    perf/x86/intel/uncore: Skip discovery table for offline dies (CVE-2026-43079)

    In the Linux kernel, the following vulnerability has been resolved:

    net: ioam6: fix OOB and missing lock (CVE-2026-43083)

    In the Linux kernel, the following vulnerability has been resolved:

    netfilter: nfnetlink_queue: make hash table per queue (CVE-2026-43084)

    In the Linux kernel, the following vulnerability has been resolved:

    netfilter: nfnetlink_log: initialize nfgenmsg in NLMSG_DONE terminator (CVE-2026-43085)

    In the Linux kernel, the following vulnerability has been resolved:

    ipvs: fix NULL deref in ip_vs_add_service error path (CVE-2026-43086)

    In the Linux kernel, the following vulnerability has been resolved:

    xfrm_user: fix info leak in build_mapping() (CVE-2026-43089)

    In the Linux kernel, the following vulnerability has been resolved:

    xfrm: fix refcount leak in xfrm_migrate_policy_find (CVE-2026-43090)

    In the Linux kernel, the following vulnerability has been resolved:

    xfrm: Wait for RCU readers during policy netns exit (CVE-2026-43091)

    In the Linux kernel, the following vulnerability has been resolved:

    xsk: validate MTU against usable frame size on bind (CVE-2026-43092)

    In the Linux kernel, the following vulnerability has been resolved:

    xsk: tighten UMEM headroom validation to account for tailroom and min frame (CVE-2026-43093)

    In the Linux kernel, the following vulnerability has been resolved:

    ixgbevf: add missing negotiate_features op to Hyper-V ops table (CVE-2026-43094)

    In the Linux kernel, the following vulnerability has been resolved:

    ipv4: icmp: fix null-ptr-deref in icmp_build_probe() (CVE-2026-43099)

    In the Linux kernel, the following vulnerability has been resolved:

    bridge: guard local VLAN-0 FDB helpers against NULL vlan group (CVE-2026-43100)

    In the Linux kernel, the following vulnerability has been resolved:

    ipv6: ioam: fix potential NULL dereferences in __ioam6_fill_trace_data() (CVE-2026-43101)

    In the Linux kernel, the following vulnerability has been resolved:

    xfrm: account XFRMA_IF_ID in aevent size calculation (CVE-2026-43107)

    In the Linux kernel, the following vulnerability has been resolved:

    x86: shadow stacks: proper error handling for mmap lock (CVE-2026-43109)

    In the Linux kernel, the following vulnerability has been resolved:

    fs/smb/client: fix out-of-bounds read in cifs_sanitize_prepath (CVE-2026-43112)

    In the Linux kernel, the following vulnerability has been resolved:

    netfilter: nft_set_pipapo_avx2: don't return non-matching entry on expiry (CVE-2026-43114)

    In the Linux kernel, the following vulnerability has been resolved:

    netfilter: ctnetlink: ensure safe access to master conntrack (CVE-2026-43116)

    In the Linux kernel, the following vulnerability has been resolved:

    btrfs: tracepoints: get correct superblock from dentry in event btrfs_sync_file() (CVE-2026-43117)

    In the Linux kernel, the following vulnerability has been resolved:

    btrfs: fix zero size inode with non-zero size after log replay (CVE-2026-43118)

    In the Linux kernel, the following vulnerability has been resolved:xfrm: esp: avoid in-place decrypt on     shared skb frags

    Dirty Frag and other issues in Amazon Linux kernels:https://aws.amazon.com/security/security-     bulletins/2026-027-aws/ (CVE-2026-43284)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - KVM: SEV: Protect *all* of sev_mem_enc_register_region() with kvm->lock Take and hold kvm->lock for before     checking sev_guest() in sev_mem_enc_register_region(), as sev_guest() isn't stable unless kvm->lock is     held (or KVM can guarantee KVM_SEV_INIT{2} has completed and can't rollack state). If KVM_SEV_INIT{2}     fails, KVM can end up trying to add to a not-yet-initialized sev->regions_list, e.g. triggering a #GP     Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN     NOPTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 110 UID: 0 PID: 72717     Comm: syz.15.11462 Tainted: G U W O 6.16.0-smp-DEV #1 NONE Tainted: [U]=USER, [W]=WARN, [O]=OOT_MODULE     Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 12.52.0-0 10/28/2024 RIP:
    0010:sev_mem_enc_register_region+0x3f0/0x4f0 ../include/linux/list.h:83 Code: <41> 80 3c 04 00 74 08 4c 89     ff e8 f1 c7 a2 00 49 39 ed 0f 84 c6 00 RSP: 0018:ffff88838647fbb8 EFLAGS: 00010256 RAX: dffffc0000000000     RBX: 1ffff92015cf1e0b RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000001000 RDI:
    ffff888367870000 RBP: ffffc900ae78f050 R08: ffffea000d9e0007 R09: 1ffffd4001b3c000 R10: dffffc0000000000     R11: fffff94001b3c001 R12: 0000000000000000 R13: ffff8982ab0bde00 R14: ffffc900ae78f058 R15:
    0000000000000000 FS: 00007f34e9dc66c0(0000) GS:ffff89ee64d33000(0000) knlGS:0000000000000000 CS: 0010 DS:
    0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe180adef98 CR3: 000000047210e000 CR4: 0000000000350ef0 Call     Trace: <TASK> kvm_arch_vm_ioctl+0xa72/0x1240 ../arch/x86/kvm/x86.c:7371 kvm_vm_ioctl+0x649/0x990     ../virt/kvm/kvm_main.c:5363 __se_sys_ioctl+0x101/0x170 ../fs/ioctl.c:51 do_syscall_x64     ../arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x6f/0x1f0 ../arch/x86/entry/syscall_64.c:94     entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f34e9f7e9a9 Code: <48> 3d 01 f0 ff ff 73 01 c3 48 c7     c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f34e9dc6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010     RAX: ffffffffffffffda RBX: 00007f34ea1a6080 RCX: 00007f34e9f7e9a9 RDX: 0000200000000280 RSI:
    000000008010aebb RDI: 0000000000000007 RBP: 00007f34ea000d69 R08: 0000000000000000 R09: 0000000000000000     R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14:
    00007f34ea1a6080 R15: 00007ffce77197a8 </TASK> with a syzlang reproducer that looks like:
    syz_kvm_add_vcpu$x86(0x0, &(0x7f0000000040)={0x0, &(0x7f0000000180)=ANY=[], 0x70}) (async)     syz_kvm_add_vcpu$x86(0x0, &(0x7f0000000080)={0x0, &(0x7f0000000180)=ANY=[@ANYBLOB=...], 0x4f}) (async)     r0 = openat$kvm(0xffffffffffffff9c, &(0x7f0000000200), 0x0, 0x0) r1 = ioctl$KVM_CREATE_VM(r0, 0xae01, 0x0)     r2 = openat$kvm(0xffffffffffffff9c, &(0x7f0000000240), 0x0, 0x0) r3 = ioctl$KVM_CREATE_VM(r2, 0xae01, 0x0)     ioctl$KVM_SET_CLOCK(r3, 0xc008aeba, &(0x7f0000000040)={0x1, 0x8, 0x0, 0x5625e9b0}) (async)     ioctl$KVM_SET_PIT2(r3, 0x8010aebb, &(0x7f0000000280)={[...], 0x5}) (async) ioctl$KVM_SET_PIT2(r1,     0x4070aea0, 0x0) (async) r4 = ioctl$KVM_CREATE_VM(0xffffffffffffffff, 0xae01, 0x0)     openat$kvm(0xffffffffffffff9c, 0x0, 0x0, 0x0) (async) ioctl$KVM_SET_USER_MEMORY_REGION(r4, 0x4020ae46,     &(0x7f0000000400)={0x0, 0x0, 0x0, 0x2000, &(0x7f0000001000/0x2000)=nil}) (async) r5 =     ioctl$KVM_CREATE_VCPU(r4, 0xae41, 0x2) close(r0) (async) openat$kvm(0xffffffffffffff9c, &(0x7f0000000000),     0x8000, 0x0) (async) ioctl$KVM_SET_GUEST_DEBUG(r5, 0x4048ae9b, &(0x7f0000000300)={0x4376ea830d46549b, 0x0,     [0x46, 0x0, 0x0, 0x0, 0x0, 0x1000]}) (async) ioctl$KVM_RUN(r5, 0xae80, 0x0) Opportunistically use guard()     to avoid having to define a new error label and goto usage. (CVE-2026-31592)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Severity
313525	Amazon Linux 2023 : bpftool6.18, kernel6.18, kernel6.18-devel (ALAS2023-2026-1693)	Nessus	Amazon Linux Local Security Checks	high
310487	Linux Distros Unpatched Vulnerability : CVE-2026-31592	Nessus	Misc.	medium

Detections

Analytics

CVE-2026-31592

medium

Tenable Plugins

high

medium