ghsa-f8rq-3pf9-vf74
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix KASAN use-after-free Read in compute_effective_progs
Syzbot found a Use After Free bug in compute_effective_progs(). The reproducer creates a number of BPF links, and causes a fault injected alloc to fail, while calling bpf_link_detach on them. Link detach triggers the link to be freed by bpf_link_free(), which calls __cgroup_bpf_detach() and update_effective_progs(). If the memory allocation in this function fails, the function restores the pointer to the bpf_cgroup_link on the cgroup list, but the memory gets freed just after it returns. After this, every subsequent call to update_effective_progs() causes this already deallocated pointer to be dereferenced in prog_list_length(), and triggers KASAN UAF error.
To fix this issue don't preserve the pointer to the prog or link in the list, but remove it and replace it with a dummy prog without shrinking the table. The subsequent call to __cgroup_bpf_detach() or __cgroup_bpf_detach() will correct it.
{
"affected": [],
"aliases": [
"CVE-2022-50219"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-06-18T11:15:52Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix KASAN use-after-free Read in compute_effective_progs\n\nSyzbot found a Use After Free bug in compute_effective_progs().\nThe reproducer creates a number of BPF links, and causes a fault\ninjected alloc to fail, while calling bpf_link_detach on them.\nLink detach triggers the link to be freed by bpf_link_free(),\nwhich calls __cgroup_bpf_detach() and update_effective_progs().\nIf the memory allocation in this function fails, the function restores\nthe pointer to the bpf_cgroup_link on the cgroup list, but the memory\ngets freed just after it returns. After this, every subsequent call to\nupdate_effective_progs() causes this already deallocated pointer to be\ndereferenced in prog_list_length(), and triggers KASAN UAF error.\n\nTo fix this issue don\u0027t preserve the pointer to the prog or link in the\nlist, but remove it and replace it with a dummy prog without shrinking\nthe table. The subsequent call to __cgroup_bpf_detach() or\n__cgroup_bpf_detach() will correct it.",
"id": "GHSA-f8rq-3pf9-vf74",
"modified": "2025-06-18T12:30:56Z",
"published": "2025-06-18T12:30:56Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-50219"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1f8ca9c40e6222ce431e9ba5dae3cccce8ef9443"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/3527e3cbb84d8868c4d4e91ba55915f96d39ec3d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/4c46091ee985ae84c60c5e95055d779fcd291d87"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/6336388715afa419cc97d0255bda3bba1b96b7ca"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/be001f9da71eaa3b61e186fb88bde3279728bdca"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date |
|---|
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