{
  "cveId": "CVE-2026-90170",
  "url": "https://patchblox.com/security/cve/CVE-2026-90170",
  "summary": "CVE-2026-90170 is fixed in 2 products on 1 platform, first by DEBIAN-CVE-2026-90170, released September 23, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "ksmbd: validate ipc response length before dereferencing its fields",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  ksmbd: validate ipc response length before dereferencing its fields  ipc_validate_msg() computes the expected message size by reading length fields out of the response buffer supplied by the userspace ksmbd daemon (payload_sz, session_key_len, ngroups, ...).  Those fields are read before the buffer is verified to be large enough to contain the struct they belong to, so a short response makes the read land past the end of the allocation.  handle_response() sizes entry-\u003Eresponse purely from the netlink attribute length (nla_len()) and only guards the leading handle read, so the daemon can install a response as small as the kmalloc-8 object seen below.  When ipc_msg_send_request() then calls ipc_validate_msg() for a KSMBD_EVENT_RPC_REQUEST, the cast to struct ksmbd_rpc_command reads resp-\u003Epayload_sz at offset 8 of an 8-byte allocation:  [ 3697.841381] ================================================================== [ 3697.844099] BUG: KASAN: slab-out-of-bounds in ipc_msg_send_request\u002B0x763/0x800 [ 3697.846604] Read of size 4 at addr ffff888105f95910 by task kworker/4:3/20682 [ 3697.849061] [ 3697.849801] CPU: 4 UID: 0 PID: 20682 Comm: kworker/4:3 Not tainted 7.2.0-rc3-next-20260717-virtme #117 PREEMPT(lazy) [ 3697.850077] Hardware name: QEMU Standard PC (i440FX \u002B PIIX, 1996), BIOS 1.17.0-debian-1.17.0-1 04/01/2014 [ 3697.850303] Workqueue: ksmbd-io handle_ksmbd_work [ 3697.850592] Call Trace: [ 3697.850794]  \u003CTASK\u003E [ 3697.850952]  __dump_stack\u002B0x21/0x60 [ 3697.851239]  dump_stack_lvl\u002B0xc2/0x100 [ 3697.851528]  print_address_description\u002B0x77/0x200 [ 3697.851816]  ? ipc_msg_send_request\u002B0x763/0x800 [ 3697.852024]  print_report\u002B0x58/0x70 [ 3697.852316]  kasan_report\u002B0x117/0x150 [ 3697.852585]  ? down_write\u002B0x146/0x1f0 [ 3697.852809]  ? ipc_msg_send_request\u002B0x763/0x800 [ 3697.853082]  ipc_msg_send_request\u002B0x763/0x800 [ 3697.853385]  ? __pfx_ipc_msg_send_request\u002B0x10/0x10 [ 3697.853604]  ? kasan_unpoison\u002B0x48/0x70 [ 3697.853936]  ? __pfx___up_read\u002B0x10/0x10 [ 3697.854221]  ksmbd_rpc_ioctl\u002B0x380/0x520 [ 3697.854542]  ? __pfx_ksmbd_rpc_ioctl\u002B0x10/0x10 [ 3697.854757]  ? kasan_unpoison\u002B0x48/0x70 [ 3697.854962]  ? copy_from_kernel_nofault\u002B0x32c/0x4e0 [ 3697.855166]  ? kasan_unpoison\u002B0x48/0x70 [ 3697.855416]  fsctl_pipe_transceive\u002B0x139/0x7a0 [ 3697.855705]  ? __pfx_copy_from_kernel_nofault\u002B0x10/0x10 [ 3697.855937]  ? __pfx_fsctl_pipe_transceive\u002B0x10/0x10 [ 3697.856388]  ? __sanitizer_cov_trace_switch\u002B0x7b/0x140 [ 3697.856620]  smb2_ioctl\u002B0x1141/0x3420 [ 3697.856994]  ? __pfx_smb2_ioctl\u002B0x10/0x10 [ 3697.857182]  ? get_smb2_cmd_val\u002B0xe3/0x1c0 [ 3697.857655]  handle_ksmbd_work\u002B0x9ad/0x15e0 [ 3697.858034]  ? __pfx_handle_ksmbd_work\u002B0x10/0x10 [ 3697.858251]  ? lock_release\u002B0xf7/0x360 [ 3697.858466]  ? process_scheduled_works\u002B0x954/0x1600 [ 3697.858698]  ? process_scheduled_works\u002B0x954/0x1600 [ 3697.858905]  process_scheduled_works\u002B0xc22/0x1600 [ 3697.859368]  ? __pfx_process_scheduled_works\u002B0x10/0x10 [ 3697.859637]  ? __pfx_assign_work\u002B0x10/0x10 [ 3697.859896]  ? lock_is_held_type\u002B0x7b/0x110 [ 3697.860146]  worker_thread\u002B0x975/0xee0 [ 3697.860524]  ? __pfx_do_raw_spin_lock\u002B0x10/0x10 [ 3697.860830]  ? __kthread_parkme\u002B0x21e/0x260 [ 3697.861105]  kthread\u002B0x3a6/0x490 [ 3697.861423]  ? __pfx_worker_thread\u002B0x10/0x10 [ 3697.861643]  ? __pfx_kthread\u002B0x10/0x10 [ 3697.861878]  ret_from_fork\u002B0x55a/0xa20 [ 3697.862194]  ? __pfx_ret_from_fork\u002B0x10/0x10 [ 3697.862480]  ? __pfx_kthread\u002B0x10/0x10 [ 3697.862714]  ret_from_fork_asm\u002B0x1a/0x30 [ 3697.862965]  \u003C/TASK\u003E [ 3697.863039] [ 3697.938882] Allocated by task 20761: [ 3697.940257]  kasan_save_track\u002B0x3e/0x80 [ 3697.941782]  __kasan_kmalloc\u002B0x72/0x90 [ 3697.943228]  __kvmalloc_node_noprof\u002B0x3e9/0x6a0 [ 3697.944948]  handle_generic_event\u002B0x59b/0x750 [ 3697.946592]  genl_family_rcv_msg_doit\u002B0x3d6/0x560 [ 3697.946977]  genl_rcv_msg\u002B0x67c/0x900 [ 3697.947224]  netlink_rcv_skb\u002B0x286/0x580 [ 3697.947488]  genl_rcv\u002B0x2d/0x80 [ 3 ---truncated---",
  "published": "2026-09-17T17:17:10Z",
  "severity": "Moderate",
  "cvss": 7.1,
  "epss": 0.002,
  "epssPercentile": 0.09891,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "vendorAdvisory": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-90170",
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "6.12.111-1",
      "fix": "DEBIAN-CVE-2026-90170",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-90170",
      "released": "2026-09-23T19:19:02Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.2.6-1",
      "fix": "DEBIAN-CVE-2026-90170",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-90170",
      "released": "2026-09-23T19:19:02Z"
    },
    {
      "platform": "linux",
      "product": "linux-6.12",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "6.12.111-1~deb12u1",
      "fix": "DEBIAN-CVE-2026-90170",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-90170",
      "released": "2026-09-23T19:19:02Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T13:06:02Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}