{
  "cveId": "CVE-2026-90174",
  "url": "https://patchblox.com/security/cve/CVE-2026-90174",
  "summary": "CVE-2026-90174 is fixed in linux on 1 platform, first by DEBIAN-CVE-2026-90174, released September 23, 2026. It is not reported as exploited. Patch Radar priority: High.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  ksmbd: fix slab-out-of-bounds read in ksmbd_allo...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  ksmbd: fix slab-out-of-bounds read in ksmbd_alloc_user()  ksmbd_alloc_user() copies resp-\u003Ehash_sz bytes out of the mountd IPC login response with  \tuser-\u003Epasskey_sz = resp-\u003Ehash_sz; \tuser-\u003Epasskey = kmalloc(resp-\u003Ehash_sz, KSMBD_DEFAULT_GFP); \tif (user-\u003Epasskey) \t\tmemcpy(user-\u003Epasskey, resp-\u003Ehash, resp-\u003Ehash_sz);  resp-\u003Ehash_sz is a __u16 supplied by the response, but resp-\u003Ehash[] is only KSMBD_REQ_MAX_HASH_SZ bytes.  A malformed or malicious login response can set hash_sz well beyond that (up to 65535), so the memcpy() reads past the end of the response object.  ipc_validate_msg() does not bound hash_sz, so reject any response whose hash_sz exceeds the on-stack hash[] buffer before allocating and copying.  [ 2030.238706] BUG: KASAN: slab-out-of-bounds in ksmbd_alloc_user\u002B0x278/0x680 [ 2030.240549] Read of size 65535 at addr ffff888121bb6680 by task kworker/4:1/18611 [ 2030.242296] [ 2030.242710] CPU: 4 UID: 0 PID: 18611 Comm: kworker/4:1 Not tainted 7.1.0-next-20260623-virtme #96 PREEMPT(lazy) [ 2030.242732] Hardware name: QEMU Standard PC (i440FX \u002B PIIX, 1996), BIOS 1.17.0-debian-1.17.0-1 04/01/2014 [ 2030.242743] Workqueue: ksmbd-io handle_ksmbd_work [ 2030.242763] Call Trace: [ 2030.242769]  \u003CTASK\u003E [ 2030.242776]  dump_stack_lvl\u002B0xa2/0xd0 [ 2030.242794]  print_address_description\u002B0x77/0x200 [ 2030.242815]  ? ksmbd_alloc_user\u002B0x278/0x680 [ 2030.242831]  print_report\u002B0x58/0x70 [ 2030.242848]  kasan_report\u002B0x117/0x150 [ 2030.242869]  ? ksmbd_alloc_user\u002B0x278/0x680 [ 2030.242888]  kasan_check_range\u002B0x3c7/0x3f0 [ 2030.242908]  ? ksmbd_alloc_user\u002B0x278/0x680 [ 2030.242925]  __asan_memcpy\u002B0x29/0x70 [ 2030.242942]  ksmbd_alloc_user\u002B0x278/0x680 [ 2030.242960]  ksmbd_login_user\u002B0xc3/0x120 [ 2030.242978]  ntlm_authenticate\u002B0x5e6/0x1b00 [ 2030.243017]  ? __pfx_ntlm_authenticate\u002B0x10/0x10 [ 2030.243035]  ? ksmbd_session_lookup\u002B0x188/0x1d0 [ 2030.243054]  ? __pfx_ksmbd_session_lookup\u002B0x10/0x10 [ 2030.243090]  ? __sanitizer_cov_trace_switch\u002B0x7b/0x140 [ 2030.243108]  smb2_sess_setup\u002B0x1e4a/0x27b0 [ 2030.243126]  ? copy_from_kernel_nofault\u002B0x199/0x300 [ 2030.243156]  ? __pfx_smb2_sess_setup\u002B0x10/0x10 [ 2030.243173]  ? get_smb2_cmd_val\u002B0xe3/0x1c0 [ 2030.243208]  handle_ksmbd_work\u002B0x954/0x1280 [ 2030.243230]  ? __pfx_handle_ksmbd_work\u002B0x10/0x10 [ 2030.243249]  ? process_scheduled_works\u002B0xa07/0x1490 [ 2030.243270]  ? process_scheduled_works\u002B0xa07/0x1490 [ 2030.243291]  process_scheduled_works\u002B0xa70/0x1490 [ 2030.243320]  ? __pfx_process_scheduled_works\u002B0x10/0x10 [ 2030.243340]  ? do_raw_spin_lock\u002B0x130/0x300 [ 2030.243358]  ? lock_is_held_type\u002B0x7b/0x110 [ 2030.243388]  worker_thread\u002B0x932/0xe20 [ 2030.243415]  kthread\u002B0x38a/0x470 [ 2030.243431]  ? __pfx_worker_thread\u002B0x10/0x10 [ 2030.243451]  ? __pfx_kthread\u002B0x10/0x10 [ 2030.243467]  ret_from_fork\u002B0x484/0x910 [ 2030.243485]  ? __pfx_ret_from_fork\u002B0x10/0x10 [ 2030.243501]  ? __switch_to\u002B0xc77/0x12c0 [ 2030.243523]  ? __pfx_kthread\u002B0x10/0x10 [ 2030.243540]  ret_from_fork_asm\u002B0x1a/0x30 [ 2030.243564]  \u003C/TASK\u003E [ 2030.243570] [ 2030.290164] Allocated by task 19279: [ 2030.290911]  kasan_save_track\u002B0x3e/0x80 [ 2030.292179]  __kasan_kmalloc\u002B0x72/0x90 [ 2030.293217]  __kvmalloc_node_noprof\u002B0x3ff/0x6b0 [ 2030.294467]  handle_generic_event\u002B0x59b/0x750 [ 2030.295345]  genl_family_rcv_msg_doit\u002B0x238/0x340 [ 2030.296553]  genl_rcv_msg\u002B0x606/0x7b0 [ 2030.297129]  netlink_rcv_skb\u002B0x22b/0x4a0 [ 2030.298500]  genl_rcv\u002B0x2d/0x40 [ 2030.299273]  netlink_unicast\u002B0x7ba/0x930 [ 2030.300019]  netlink_sendmsg\u002B0x8c3/0xb00 [ 2030.301073]  __sock_sendmsg\u002B0xec/0x140 [ 2030.301579]  __sys_sendto\u002B0x357/0x470 [ 2030.302255]  __x64_sys_sendto\u002B0xe3/0x100 [ 2030.303425]  do_syscall_64\u002B0x135/0x460 [ 2030.304763]  entry_SYSCALL_64_after_hwframe\u002B0x77/0x7f [ 2030.305594] [ 2030.305819] The buggy address belongs to the object at ffff888121bb6640 [ 2030.305819]  which belongs to the cache kmalloc-192 of size 192 [ 2030.309595] The buggy address  ---truncated---",
  "published": "2026-09-17T17:17:11Z",
  "severity": "high",
  "cvss": 7.1,
  "cvssVector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
  "epss": 0.00167,
  "epssPercentile": 0.05951,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "6.12.115-2",
      "fix": "DEBIAN-CVE-2026-90174",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-90174",
      "released": "2026-09-23T19:19:02Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "7.2.6-1",
      "fix": "DEBIAN-CVE-2026-90174",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2026-90174",
      "released": "2026-09-23T19:19:02Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T00:53:09Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}