GHSA-RQQP-4VHV-FQRG

Vulnerability from github – Published: 2024-07-29 15:30 – Updated: 2025-11-04 00:31
VLAI
Details

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

cachefiles: fix slab-use-after-free in cachefiles_withdraw_cookie()

We got the following issue in our fault injection stress test:

================================================================== BUG: KASAN: slab-use-after-free in cachefiles_withdraw_cookie+0x4d9/0x600 Read of size 8 at addr ffff888118efc000 by task kworker/u78:0/109

CPU: 13 PID: 109 Comm: kworker/u78:0 Not tainted 6.8.0-dirty #566 Call Trace: kasan_report+0x93/0xc0 cachefiles_withdraw_cookie+0x4d9/0x600 fscache_cookie_state_machine+0x5c8/0x1230 fscache_cookie_worker+0x91/0x1c0 process_one_work+0x7fa/0x1800 [...]

Allocated by task 117: kmalloc_trace+0x1b3/0x3c0 cachefiles_acquire_volume+0xf3/0x9c0 fscache_create_volume_work+0x97/0x150 process_one_work+0x7fa/0x1800 [...]

Freed by task 120301: kfree+0xf1/0x2c0 cachefiles_withdraw_cache+0x3fa/0x920 cachefiles_put_unbind_pincount+0x1f6/0x250 cachefiles_daemon_release+0x13b/0x290 __fput+0x204/0xa00 task_work_run+0x139/0x230 do_exit+0x87a/0x29b0 [...] ==================================================================

Following is the process that triggers the issue:

       p1                |             p2

                          fscache_begin_lookup
                           fscache_begin_volume_access
                            fscache_cache_is_live(fscache_cache)

cachefiles_daemon_release cachefiles_put_unbind_pincount cachefiles_daemon_unbind cachefiles_withdraw_cache fscache_withdraw_cache fscache_set_cache_state(cache, FSCACHE_CACHE_IS_WITHDRAWN); cachefiles_withdraw_objects(cache) fscache_wait_for_objects(fscache) atomic_read(&fscache_cache->object_count) == 0 fscache_perform_lookup cachefiles_lookup_cookie cachefiles_alloc_object refcount_set(&object->ref, 1); object->volume = volume fscache_count_object(vcookie->cache); atomic_inc(&fscache_cache->object_count) cachefiles_withdraw_volumes cachefiles_withdraw_volume fscache_withdraw_volume __cachefiles_free_volume kfree(cachefiles_volume) fscache_cookie_state_machine cachefiles_withdraw_cookie cache = object->volume->cache; // cachefiles_volume UAF !!!

After setting FSCACHE_CACHE_IS_WITHDRAWN, wait for all the cookie lookups to complete first, and then wait for fscache_cache->object_count == 0 to avoid the cookie exiting after the volume has been freed and triggering the above issue. Therefore call fscache_withdraw_volume() before calling cachefiles_withdraw_objects().

This way, after setting FSCACHE_CACHE_IS_WITHDRAWN, only the following two cases will occur: 1) fscache_begin_lookup fails in fscache_begin_volume_access(). 2) fscache_withdraw_volume() will ensure that fscache_count_object() has been executed before calling fscache_wait_for_objects().

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2024-41057"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-416"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2024-07-29T15:15:13Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ncachefiles: fix slab-use-after-free in cachefiles_withdraw_cookie()\n\nWe got the following issue in our fault injection stress test:\n\n==================================================================\nBUG: KASAN: slab-use-after-free in cachefiles_withdraw_cookie+0x4d9/0x600\nRead of size 8 at addr ffff888118efc000 by task kworker/u78:0/109\n\nCPU: 13 PID: 109 Comm: kworker/u78:0 Not tainted 6.8.0-dirty #566\nCall Trace:\n \u003cTASK\u003e\n kasan_report+0x93/0xc0\n cachefiles_withdraw_cookie+0x4d9/0x600\n fscache_cookie_state_machine+0x5c8/0x1230\n fscache_cookie_worker+0x91/0x1c0\n process_one_work+0x7fa/0x1800\n [...]\n\nAllocated by task 117:\n kmalloc_trace+0x1b3/0x3c0\n cachefiles_acquire_volume+0xf3/0x9c0\n fscache_create_volume_work+0x97/0x150\n process_one_work+0x7fa/0x1800\n [...]\n\nFreed by task 120301:\n kfree+0xf1/0x2c0\n cachefiles_withdraw_cache+0x3fa/0x920\n cachefiles_put_unbind_pincount+0x1f6/0x250\n cachefiles_daemon_release+0x13b/0x290\n __fput+0x204/0xa00\n task_work_run+0x139/0x230\n do_exit+0x87a/0x29b0\n [...]\n==================================================================\n\nFollowing is the process that triggers the issue:\n\n           p1                |             p2\n------------------------------------------------------------\n                              fscache_begin_lookup\n                               fscache_begin_volume_access\n                                fscache_cache_is_live(fscache_cache)\ncachefiles_daemon_release\n cachefiles_put_unbind_pincount\n  cachefiles_daemon_unbind\n   cachefiles_withdraw_cache\n    fscache_withdraw_cache\n     fscache_set_cache_state(cache, FSCACHE_CACHE_IS_WITHDRAWN);\n    cachefiles_withdraw_objects(cache)\n    fscache_wait_for_objects(fscache)\n      atomic_read(\u0026fscache_cache-\u003eobject_count) == 0\n                              fscache_perform_lookup\n                               cachefiles_lookup_cookie\n                                cachefiles_alloc_object\n                                 refcount_set(\u0026object-\u003eref, 1);\n                                 object-\u003evolume = volume\n                                 fscache_count_object(vcookie-\u003ecache);\n                                  atomic_inc(\u0026fscache_cache-\u003eobject_count)\n    cachefiles_withdraw_volumes\n     cachefiles_withdraw_volume\n      fscache_withdraw_volume\n      __cachefiles_free_volume\n       kfree(cachefiles_volume)\n                              fscache_cookie_state_machine\n                               cachefiles_withdraw_cookie\n                                cache = object-\u003evolume-\u003ecache;\n                                // cachefiles_volume UAF !!!\n\nAfter setting FSCACHE_CACHE_IS_WITHDRAWN, wait for all the cookie lookups\nto complete first, and then wait for fscache_cache-\u003eobject_count == 0 to\navoid the cookie exiting after the volume has been freed and triggering\nthe above issue. Therefore call fscache_withdraw_volume() before calling\ncachefiles_withdraw_objects().\n\nThis way, after setting FSCACHE_CACHE_IS_WITHDRAWN, only the following two\ncases will occur:\n1) fscache_begin_lookup fails in fscache_begin_volume_access().\n2) fscache_withdraw_volume() will ensure that fscache_count_object() has\n   been executed before calling fscache_wait_for_objects().",
  "id": "GHSA-rqqp-4vhv-fqrg",
  "modified": "2025-11-04T00:31:00Z",
  "published": "2024-07-29T15:30:44Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-41057"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5d8f805789072ea7fd39504694b7bd17e5f751c4"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/8de253177112a47c9af157d23ae934779188b4e1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9e67589a4a7b7e5660b524d1d5fe61242bcbcc11"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ef81340401e8a371d6b17f69e76d861920972cfe"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.


Loading…

Loading…

Loading…

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.

Loading…

Detection rules are retrieved from Rulezet.

Loading…

Loading…

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.


Loading…