ghsa-c93g-8734-9cr8
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
cachefiles: remove requests from xarray during flushing requests
Even with CACHEFILES_DEAD set, we can still read the requests, so in the following concurrency the request may be used after it has been freed:
mount | daemon_thread1 | daemon_thread2
cachefiles_ondemand_init_object cachefiles_ondemand_send_req REQ_A = kzalloc(sizeof(*req) + data_len) wait_for_completion(&REQ_A->done) cachefiles_daemon_read cachefiles_ondemand_daemon_read // close dev fd cachefiles_flush_reqs complete(&REQ_A->done) kfree(REQ_A) xa_lock(&cache->reqs); cachefiles_ondemand_select_req req->msg.opcode != CACHEFILES_OP_READ // req use-after-free !!! xa_unlock(&cache->reqs); xa_destroy(&cache->reqs)
Hence remove requests from cache->reqs when flushing them to avoid accessing freed requests.
{
"affected": [],
"aliases": [
"CVE-2024-40900"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-07-12T13:15:13Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\ncachefiles: remove requests from xarray during flushing requests\n\nEven with CACHEFILES_DEAD set, we can still read the requests, so in the\nfollowing concurrency the request may be used after it has been freed:\n\n mount | daemon_thread1 | daemon_thread2\n------------------------------------------------------------\n cachefiles_ondemand_init_object\n cachefiles_ondemand_send_req\n REQ_A = kzalloc(sizeof(*req) + data_len)\n wait_for_completion(\u0026REQ_A-\u003edone)\n cachefiles_daemon_read\n cachefiles_ondemand_daemon_read\n // close dev fd\n cachefiles_flush_reqs\n complete(\u0026REQ_A-\u003edone)\n kfree(REQ_A)\n xa_lock(\u0026cache-\u003ereqs);\n cachefiles_ondemand_select_req\n req-\u003emsg.opcode != CACHEFILES_OP_READ\n // req use-after-free !!!\n xa_unlock(\u0026cache-\u003ereqs);\n xa_destroy(\u0026cache-\u003ereqs)\n\nHence remove requests from cache-\u003ereqs when flushing them to avoid\naccessing freed requests.",
"id": "GHSA-c93g-8734-9cr8",
"modified": "2024-07-12T15:31:27Z",
"published": "2024-07-12T15:31:27Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-40900"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/0fc75c5940fa634d84e64c93bfc388e1274ed013"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/37e19cf86a520d65de1de9cb330415c332a40d19"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/50d0e55356ba5b84ffb51c42704126124257e598"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/9f13aacdd4ee9a7644b2a3c96d67113cd083c9c7"
}
],
"schema_version": "1.4.0",
"severity": []
}
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.