ghsa-77p5-68v4-943h
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
cachefiles: fix slab-use-after-free in cachefiles_ondemand_daemon_read()
We got the following issue in a fuzz test of randomly issuing the restore command:
================================================================== BUG: KASAN: slab-use-after-free in cachefiles_ondemand_daemon_read+0xb41/0xb60 Read of size 8 at addr ffff888122e84088 by task ondemand-04-dae/963
CPU: 13 PID: 963 Comm: ondemand-04-dae Not tainted 6.8.0-dirty #564 Call Trace: kasan_report+0x93/0xc0 cachefiles_ondemand_daemon_read+0xb41/0xb60 vfs_read+0x169/0xb50 ksys_read+0xf5/0x1e0
Allocated by task 116: kmem_cache_alloc+0x140/0x3a0 cachefiles_lookup_cookie+0x140/0xcd0 fscache_cookie_state_machine+0x43c/0x1230 [...]
Freed by task 792: kmem_cache_free+0xfe/0x390 cachefiles_put_object+0x241/0x480 fscache_cookie_state_machine+0x5c8/0x1230 [...] ==================================================================
Following is the process that triggers the issue:
mount | daemon_thread1 | daemon_thread2
cachefiles_withdraw_cookie cachefiles_ondemand_clean_object(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
REQ_A = cachefiles_ondemand_select_req
msg->object_id = req->object->ondemand->ondemand_id
------ restore ------
cachefiles_ondemand_restore
xas_for_each(&xas, req, ULONG_MAX)
xas_set_mark(&xas, CACHEFILES_REQ_NEW)
cachefiles_daemon_read
cachefiles_ondemand_daemon_read
REQ_A = cachefiles_ondemand_select_req
copy_to_user(_buffer, msg, n)
xa_erase(&cache->reqs, id)
complete(&REQ_A->done)
------ close(fd) ------
cachefiles_ondemand_fd_release
cachefiles_put_object
cachefiles_put_object kmem_cache_free(cachefiles_object_jar, object) REQ_A->object->ondemand->ondemand_id // object UAF !!!
When we see the request within xa_lock, req->object must not have been freed yet, so grab the reference count of object before xa_unlock to avoid the above issue.
{
"affected": [],
"aliases": [
"CVE-2024-39510"
],
"database_specific": {
"cwe_ids": [
"CWE-416"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-07-12T13:15:13Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\ncachefiles: fix slab-use-after-free in cachefiles_ondemand_daemon_read()\n\nWe got the following issue in a fuzz test of randomly issuing the restore\ncommand:\n\n==================================================================\nBUG: KASAN: slab-use-after-free in cachefiles_ondemand_daemon_read+0xb41/0xb60\nRead of size 8 at addr ffff888122e84088 by task ondemand-04-dae/963\n\nCPU: 13 PID: 963 Comm: ondemand-04-dae Not tainted 6.8.0-dirty #564\nCall Trace:\n kasan_report+0x93/0xc0\n cachefiles_ondemand_daemon_read+0xb41/0xb60\n vfs_read+0x169/0xb50\n ksys_read+0xf5/0x1e0\n\nAllocated by task 116:\n kmem_cache_alloc+0x140/0x3a0\n cachefiles_lookup_cookie+0x140/0xcd0\n fscache_cookie_state_machine+0x43c/0x1230\n [...]\n\nFreed by task 792:\n kmem_cache_free+0xfe/0x390\n cachefiles_put_object+0x241/0x480\n fscache_cookie_state_machine+0x5c8/0x1230\n [...]\n==================================================================\n\nFollowing is the process that triggers the issue:\n\n mount | daemon_thread1 | daemon_thread2\n------------------------------------------------------------\ncachefiles_withdraw_cookie\n cachefiles_ondemand_clean_object(object)\n cachefiles_ondemand_send_req\n REQ_A = kzalloc(sizeof(*req) + data_len)\n wait_for_completion(\u0026REQ_A-\u003edone)\n\n cachefiles_daemon_read\n cachefiles_ondemand_daemon_read\n REQ_A = cachefiles_ondemand_select_req\n msg-\u003eobject_id = req-\u003eobject-\u003eondemand-\u003eondemand_id\n ------ restore ------\n cachefiles_ondemand_restore\n xas_for_each(\u0026xas, req, ULONG_MAX)\n xas_set_mark(\u0026xas, CACHEFILES_REQ_NEW)\n\n cachefiles_daemon_read\n cachefiles_ondemand_daemon_read\n REQ_A = cachefiles_ondemand_select_req\n copy_to_user(_buffer, msg, n)\n xa_erase(\u0026cache-\u003ereqs, id)\n complete(\u0026REQ_A-\u003edone)\n ------ close(fd) ------\n cachefiles_ondemand_fd_release\n cachefiles_put_object\n cachefiles_put_object\n kmem_cache_free(cachefiles_object_jar, object)\n REQ_A-\u003eobject-\u003eondemand-\u003eondemand_id\n // object UAF !!!\n\nWhen we see the request within xa_lock, req-\u003eobject must not have been\nfreed yet, so grab the reference count of object before xa_unlock to\navoid the above issue.",
"id": "GHSA-77p5-68v4-943h",
"modified": "2024-08-28T21:31:27Z",
"published": "2024-07-12T15:31:26Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-39510"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/3958679c49152391209b32be3357193300a51abd"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/93064676a2820420a2d37d7c8289f277fe20793d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/cb55625f8eb9d2de8be4da0c4580d48cbb32058e"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/da4a827416066191aafeeccee50a8836a826ba10"
}
],
"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"
}
]
}
- 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.