In the Linux kernel, the following vulnerability has been resolved:
padata: avoid UAF for reorder_work
Although the previous patch can avoid ps and ps UAF for _do_serial, it
can not avoid potential UAF issue for reorder_work. This issue can
happen just as below:
crypto_request crypto_request crypto_del_alg
padata_do_serial
...
padata_reorder
// processes all remaining
// requests then breaks
while (1) {
if (!padata)
break;
...
}
padata_do_serial
// new request added
list_add
// sees the new request
queue_work(reorder_work)
padata_reorder
queue_work_on(squeue->work)
...
padata_serial_worker
// completes new request,
// no more outstanding
// requests
crypto_del_alg
// free pd
invoke_padata_reorder
// UAF of pd
To avoid UAF for 'reorder_work', get 'pd' ref before put 'reorder_work'
into the 'serial_wq' and put 'pd' ref until the 'serial_wq' finish.
CVE ID: CVE-2025-21726
Vendor: Linux, Linux
Product: Linux, Linux
EPSS Score: 0.02% (probability of being exploited)
EPSS Percentile: 1.85% (scored less or equal to compared to others)
EPSS Date: 2025-03-27 (when was this score calculated)