GHSA-G3QQ-FG79-63V4
Vulnerability from github – Published: 2025-10-04 18:31 – Updated: 2025-10-04 18:31In the Linux kernel, the following vulnerability has been resolved:
nilfs2: fix potential UAF of struct nilfs_sc_info in nilfs_segctor_thread()
The finalization of nilfs_segctor_thread() can race with nilfs_segctor_kill_thread() which terminates that thread, potentially causing a use-after-free BUG as KASAN detected.
At the end of nilfs_segctor_thread(), it assigns NULL to "sc_task" member of "struct nilfs_sc_info" to indicate the thread has finished, and then notifies nilfs_segctor_kill_thread() of this using waitqueue "sc_wait_task" on the struct nilfs_sc_info.
However, here, immediately after the NULL assignment to "sc_task", it is possible that nilfs_segctor_kill_thread() will detect it and return to continue the deallocation, freeing the nilfs_sc_info structure before the thread does the notification.
This fixes the issue by protecting the NULL assignment to "sc_task" and its notification, with spinlock "sc_state_lock" of the struct nilfs_sc_info. Since nilfs_segctor_kill_thread() does a final check to see if "sc_task" is NULL with "sc_state_lock" locked, this can eliminate the race.
{
"affected": [],
"aliases": [
"CVE-2023-53608"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-10-04T16:15:57Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnilfs2: fix potential UAF of struct nilfs_sc_info in nilfs_segctor_thread()\n\nThe finalization of nilfs_segctor_thread() can race with\nnilfs_segctor_kill_thread() which terminates that thread, potentially\ncausing a use-after-free BUG as KASAN detected.\n\nAt the end of nilfs_segctor_thread(), it assigns NULL to \"sc_task\" member\nof \"struct nilfs_sc_info\" to indicate the thread has finished, and then\nnotifies nilfs_segctor_kill_thread() of this using waitqueue\n\"sc_wait_task\" on the struct nilfs_sc_info.\n\nHowever, here, immediately after the NULL assignment to \"sc_task\", it is\npossible that nilfs_segctor_kill_thread() will detect it and return to\ncontinue the deallocation, freeing the nilfs_sc_info structure before the\nthread does the notification.\n\nThis fixes the issue by protecting the NULL assignment to \"sc_task\" and\nits notification, with spinlock \"sc_state_lock\" of the struct\nnilfs_sc_info. Since nilfs_segctor_kill_thread() does a final check to\nsee if \"sc_task\" is NULL with \"sc_state_lock\" locked, this can eliminate\nthe race.",
"id": "GHSA-g3qq-fg79-63v4",
"modified": "2025-10-04T18:31:16Z",
"published": "2025-10-04T18:31:16Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2023-53608"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/034cce77d52ba013ce62b4f5258c29907eb1ada5"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/0dbf0e64b91ee8fcb278aea93eb06fc7d56ecbcc"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/613bf23c070d11c525268f2945aa594704a9b764"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/6be49d100c22ffea3287a4b19d7639d259888e33"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/92684e02654c91a61a0b0561433b710bcece19fe"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b4d80bd6370b81a1725b6b8f7894802c23a14e9f"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/bae009a2f1b7c2011d2e92d8c84868d315c0b97e"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f32297dba338dc06d62286dedb3cdbd5175b1719"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
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