GHSA-XCG5-9P3P-FGRJ

Vulnerability from github – Published: 2026-02-14 18:30 – Updated: 2026-02-14 18:30
VLAI?
Details

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

cgroup/dmem: avoid pool UAF

An UAF issue was observed:

BUG: KASAN: slab-use-after-free in page_counter_uncharge+0x65/0x150 Write of size 8 at addr ffff888106715440 by task insmod/527

CPU: 4 UID: 0 PID: 527 Comm: insmod 6.19.0-rc7-next-20260129+ #11 Tainted: [O]=OOT_MODULE Call Trace: dump_stack_lvl+0x82/0xd0 kasan_report+0xca/0x100 kasan_check_range+0x39/0x1c0 page_counter_uncharge+0x65/0x150 dmem_cgroup_uncharge+0x1f/0x260

Allocated by task 527:

Freed by task 0:

The buggy address belongs to the object at ffff888106715400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 64 bytes inside of freed 512-byte region [ffff888106715400, ffff888106715600)

The buggy address belongs to the physical page:

Memory state around the buggy address: ffff888106715300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888106715380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc

ffff888106715400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888106715480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888106715500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

The issue occurs because a pool can still be held by a caller after its associated memory region is unregistered. The current implementation frees the pool even if users still hold references to it (e.g., before uncharge operations complete).

This patch adds a reference counter to each pool, ensuring that a pool is only freed when its reference count drops to zero.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2026-23195"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-02-14T17:15:57Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ncgroup/dmem: avoid pool UAF\n\nAn UAF issue was observed:\n\nBUG: KASAN: slab-use-after-free in page_counter_uncharge+0x65/0x150\nWrite of size 8 at addr ffff888106715440 by task insmod/527\n\nCPU: 4 UID: 0 PID: 527 Comm: insmod    6.19.0-rc7-next-20260129+ #11\nTainted: [O]=OOT_MODULE\nCall Trace:\n\u003cTASK\u003e\ndump_stack_lvl+0x82/0xd0\nkasan_report+0xca/0x100\nkasan_check_range+0x39/0x1c0\npage_counter_uncharge+0x65/0x150\ndmem_cgroup_uncharge+0x1f/0x260\n\nAllocated by task 527:\n\nFreed by task 0:\n\nThe buggy address belongs to the object at ffff888106715400\nwhich belongs to the cache kmalloc-512 of size 512\nThe buggy address is located 64 bytes inside of\nfreed 512-byte region [ffff888106715400, ffff888106715600)\n\nThe buggy address belongs to the physical page:\n\nMemory state around the buggy address:\nffff888106715300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc\nffff888106715380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc\n\u003effff888106715400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb\n\t\t\t\t     ^\nffff888106715480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb\nffff888106715500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb\n\nThe issue occurs because a pool can still be held by a caller after its\nassociated memory region is unregistered. The current implementation frees\nthe pool even if users still hold references to it (e.g., before uncharge\noperations complete).\n\nThis patch adds a reference counter to each pool, ensuring that a pool is\nonly freed when its reference count drops to zero.",
  "id": "GHSA-xcg5-9p3p-fgrj",
  "modified": "2026-02-14T18:30:16Z",
  "published": "2026-02-14T18:30:16Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23195"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/99a2ef500906138ba58093b9893972a5c303c734"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d3081353acaa6a638dcf75726066ea556a2de8d5"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}


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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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  • 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.


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