GHSA-7VG6-6285-WMRM

Vulnerability from github – Published: 2026-09-17 18:31 – Updated: 2026-09-17 18:31
VLAI
Details

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->response 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->payload_sz at offset 8 of an 8-byte allocation:

[ 3697.841381] ================================================================== [ 3697.844099] BUG: KASAN: slab-out-of-bounds in ipc_msg_send_request+0x763/0x800 [ 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 + 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] [ 3697.850952] __dump_stack+0x21/0x60 [ 3697.851239] dump_stack_lvl+0xc2/0x100 [ 3697.851528] print_address_description+0x77/0x200 [ 3697.851816] ? ipc_msg_send_request+0x763/0x800 [ 3697.852024] print_report+0x58/0x70 [ 3697.852316] kasan_report+0x117/0x150 [ 3697.852585] ? down_write+0x146/0x1f0 [ 3697.852809] ? ipc_msg_send_request+0x763/0x800 [ 3697.853082] ipc_msg_send_request+0x763/0x800 [ 3697.853385] ? __pfx_ipc_msg_send_request+0x10/0x10 [ 3697.853604] ? kasan_unpoison+0x48/0x70 [ 3697.853936] ? __pfxupread+0x10/0x10 [ 3697.854221] ksmbd_rpc_ioctl+0x380/0x520 [ 3697.854542] ? pfx_ksmbd_rpc_ioctl+0x10/0x10 [ 3697.854757] ? kasan_unpoison+0x48/0x70 [ 3697.854962] ? copy_from_kernel_nofault+0x32c/0x4e0 [ 3697.855166] ? kasan_unpoison+0x48/0x70 [ 3697.855416] fsctl_pipe_transceive+0x139/0x7a0 [ 3697.855705] ? __pfx_copy_from_kernel_nofault+0x10/0x10 [ 3697.855937] ? __pfx_fsctl_pipe_transceive+0x10/0x10 [ 3697.856388] ? __sanitizer_cov_trace_switch+0x7b/0x140 [ 3697.856620] smb2_ioctl+0x1141/0x3420 [ 3697.856994] ? __pfx_smb2_ioctl+0x10/0x10 [ 3697.857182] ? get_smb2_cmd_val+0xe3/0x1c0 [ 3697.857655] handle_ksmbd_work+0x9ad/0x15e0 [ 3697.858034] ? __pfx_handle_ksmbd_work+0x10/0x10 [ 3697.858251] ? lock_release+0xf7/0x360 [ 3697.858466] ? process_scheduled_works+0x954/0x1600 [ 3697.858698] ? process_scheduled_works+0x954/0x1600 [ 3697.858905] process_scheduled_works+0xc22/0x1600 [ 3697.859368] ? __pfx_process_scheduled_works+0x10/0x10 [ 3697.859637] ? __pfx_assign_work+0x10/0x10 [ 3697.859896] ? lock_is_held_type+0x7b/0x110 [ 3697.860146] worker_thread+0x975/0xee0 [ 3697.860524] ? __pfx_do_raw_spin_lock+0x10/0x10 [ 3697.860830] ? __kthread_parkme+0x21e/0x260 [ 3697.861105] kthread+0x3a6/0x490 [ 3697.861423] ? __pfx_worker_thread+0x10/0x10 [ 3697.861643] ? __pfx_kthread+0x10/0x10 [ 3697.861878] ret_from_fork+0x55a/0xa20 [ 3697.862194] ? __pfx_ret_from_fork+0x10/0x10 [ 3697.862480] ? __pfx_kthread+0x10/0x10 [ 3697.862714] ret_from_fork_asm+0x1a/0x30 [ 3697.862965] [ 3697.863039] [ 3697.938882] Allocated by task 20761: [ 3697.940257] kasan_save_track+0x3e/0x80 [ 3697.941782] __kasan_kmalloc+0x72/0x90 [ 3697.943228] __kvmalloc_node_noprof+0x3e9/0x6a0 [ 3697.944948] handle_generic_event+0x59b/0x750 [ 3697.946592] genl_family_rcv_msg_doit+0x3d6/0x560 [ 3697.946977] genl_rcv_msg+0x67c/0x900 [ 3697.947224] netlink_rcv_skb+0x286/0x580 [ 3697.947488] genl_rcv+0x2d/0x80 [ 3 ---truncated---

Show details on source website
To clipboard 

{
  "affected": [],
  "aliases": [
    "CVE-2026-90170"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-17T17:17:10Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: validate ipc response length before dereferencing its fields\n\nipc_validate_msg() computes the expected message size by reading length\nfields out of the response buffer supplied by the userspace ksmbd daemon\n(payload_sz, session_key_len, ngroups, ...).  Those fields are read before\nthe buffer is verified to be large enough to contain the struct they belong\nto, so a short response makes the read land past the end of the allocation.\n\nhandle_response() sizes entry-\u003eresponse purely from the netlink attribute\nlength (nla_len()) and only guards the leading handle read, so the daemon\ncan install a response as small as the kmalloc-8 object seen below.  When\nipc_msg_send_request() then calls ipc_validate_msg() for a\nKSMBD_EVENT_RPC_REQUEST, the cast to struct ksmbd_rpc_command reads\nresp-\u003epayload_sz at offset 8 of an 8-byte allocation:\n\n[ 3697.841381] ==================================================================\n[ 3697.844099] BUG: KASAN: slab-out-of-bounds in ipc_msg_send_request+0x763/0x800\n[ 3697.846604] Read of size 4 at addr ffff888105f95910 by task kworker/4:3/20682\n[ 3697.849061]\n[ 3697.849801] CPU: 4 UID: 0 PID: 20682 Comm: kworker/4:3 Not tainted 7.2.0-rc3-next-20260717-virtme #117 PREEMPT(lazy)\n[ 3697.850077] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-debian-1.17.0-1 04/01/2014\n[ 3697.850303] Workqueue: ksmbd-io handle_ksmbd_work\n[ 3697.850592] Call Trace:\n[ 3697.850794]  \u003cTASK\u003e\n[ 3697.850952]  __dump_stack+0x21/0x60\n[ 3697.851239]  dump_stack_lvl+0xc2/0x100\n[ 3697.851528]  print_address_description+0x77/0x200\n[ 3697.851816]  ? ipc_msg_send_request+0x763/0x800\n[ 3697.852024]  print_report+0x58/0x70\n[ 3697.852316]  kasan_report+0x117/0x150\n[ 3697.852585]  ? down_write+0x146/0x1f0\n[ 3697.852809]  ? ipc_msg_send_request+0x763/0x800\n[ 3697.853082]  ipc_msg_send_request+0x763/0x800\n[ 3697.853385]  ? __pfx_ipc_msg_send_request+0x10/0x10\n[ 3697.853604]  ? kasan_unpoison+0x48/0x70\n[ 3697.853936]  ? __pfx___up_read+0x10/0x10\n[ 3697.854221]  ksmbd_rpc_ioctl+0x380/0x520\n[ 3697.854542]  ? __pfx_ksmbd_rpc_ioctl+0x10/0x10\n[ 3697.854757]  ? kasan_unpoison+0x48/0x70\n[ 3697.854962]  ? copy_from_kernel_nofault+0x32c/0x4e0\n[ 3697.855166]  ? kasan_unpoison+0x48/0x70\n[ 3697.855416]  fsctl_pipe_transceive+0x139/0x7a0\n[ 3697.855705]  ? __pfx_copy_from_kernel_nofault+0x10/0x10\n[ 3697.855937]  ? __pfx_fsctl_pipe_transceive+0x10/0x10\n[ 3697.856388]  ? __sanitizer_cov_trace_switch+0x7b/0x140\n[ 3697.856620]  smb2_ioctl+0x1141/0x3420\n[ 3697.856994]  ? __pfx_smb2_ioctl+0x10/0x10\n[ 3697.857182]  ? get_smb2_cmd_val+0xe3/0x1c0\n[ 3697.857655]  handle_ksmbd_work+0x9ad/0x15e0\n[ 3697.858034]  ? __pfx_handle_ksmbd_work+0x10/0x10\n[ 3697.858251]  ? lock_release+0xf7/0x360\n[ 3697.858466]  ? process_scheduled_works+0x954/0x1600\n[ 3697.858698]  ? process_scheduled_works+0x954/0x1600\n[ 3697.858905]  process_scheduled_works+0xc22/0x1600\n[ 3697.859368]  ? __pfx_process_scheduled_works+0x10/0x10\n[ 3697.859637]  ? __pfx_assign_work+0x10/0x10\n[ 3697.859896]  ? lock_is_held_type+0x7b/0x110\n[ 3697.860146]  worker_thread+0x975/0xee0\n[ 3697.860524]  ? __pfx_do_raw_spin_lock+0x10/0x10\n[ 3697.860830]  ? __kthread_parkme+0x21e/0x260\n[ 3697.861105]  kthread+0x3a6/0x490\n[ 3697.861423]  ? __pfx_worker_thread+0x10/0x10\n[ 3697.861643]  ? __pfx_kthread+0x10/0x10\n[ 3697.861878]  ret_from_fork+0x55a/0xa20\n[ 3697.862194]  ? __pfx_ret_from_fork+0x10/0x10\n[ 3697.862480]  ? __pfx_kthread+0x10/0x10\n[ 3697.862714]  ret_from_fork_asm+0x1a/0x30\n[ 3697.862965]  \u003c/TASK\u003e\n[ 3697.863039]\n[ 3697.938882] Allocated by task 20761:\n[ 3697.940257]  kasan_save_track+0x3e/0x80\n[ 3697.941782]  __kasan_kmalloc+0x72/0x90\n[ 3697.943228]  __kvmalloc_node_noprof+0x3e9/0x6a0\n[ 3697.944948]  handle_generic_event+0x59b/0x750\n[ 3697.946592]  genl_family_rcv_msg_doit+0x3d6/0x560\n[ 3697.946977]  genl_rcv_msg+0x67c/0x900\n[ 3697.947224]  netlink_rcv_skb+0x286/0x580\n[ 3697.947488]  genl_rcv+0x2d/0x80\n[ 3\n---truncated---",
  "id": "GHSA-7vg6-6285-wmrm",
  "modified": "2026-09-17T18:31:54Z",
  "published": "2026-09-17T18:31:53Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-90170"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0aa8f94bfd4d818284c8a7ce0040d40ca1ec3595"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/17b7d1a2b4d5473df5dca8c9a07d65021806c23a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/398cba4b646a6c08ff3d79e6b1e70e5ddae8a065"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c494fcf8e89e3c970e13d78ebe62bf5d8f2b1c52"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e9b33376bd07bca4175f7bcc2d6034ef250f8181"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.