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.
Metrics
Affected Vendors & Products
| Source | ID | Title |
|---|---|---|
Debian DLA |
DLA-4008-1 | linux-6.1 security update |
Debian DSA |
DSA-5731-1 | linux security update |
Ubuntu USN |
USN-6999-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-6999-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7004-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7005-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7005-2 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7008-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7029-1 | Linux kernel vulnerabilities |
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
Mon, 03 Nov 2025 22:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
Wed, 06 Nov 2024 20:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Thu, 12 Sep 2024 20:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Wed, 11 Sep 2024 13:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Wed, 28 Aug 2024 20:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.10:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.10:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.10:rc3:*:*:*:*:*:* |
|
| Vendors & Products |
Linux
Linux linux Kernel |
|
| Metrics |
cvssV3_1
|
cvssV3_1
|
Mon, 12 Aug 2024 19:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-416 | |
| Metrics |
cvssV3_1
|
cvssV3_1
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-11-03T21:56:30.908Z
Reserved: 2024-06-25T14:23:23.753Z
Link: CVE-2024-39510
Updated: 2025-11-03T21:56:30.908Z
Status : Modified
Published: 2024-07-12T13:15:13.283
Modified: 2025-11-03T22:17:06.787
Link: CVE-2024-39510
OpenCVE Enrichment
No data.
Debian DLA
Debian DSA
Ubuntu USN