Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: ublk: fix use-after-free in ublk_partition_scan_work A race condition exists between the async partition scan work and device teardown that can lead to a use-after-free of ub->ub_disk: 1. ublk_ctrl_start_dev() schedules partition_scan_work after add_disk() 2. ublk_stop_dev() calls ublk_stop_dev_unlocked() which does: - del_gendisk(ub->ub_disk) - ublk_detach_disk() sets ub->ub_disk = NULL - put_disk() which may free the disk 3. The worker ublk_partition_scan_work() then dereferences ub->ub_disk leading to UAF Fix this by using ublk_get_disk()/ublk_put_disk() in the worker to hold a reference to the disk during the partition scan. The spinlock in ublk_get_disk() synchronizes with ublk_detach_disk() ensuring the worker either gets a valid reference or sees NULL and exits early. Also change flush_work() to cancel_work_sync() to avoid running the partition scan work unnecessarily when the disk is already detached.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 63dfbcd59b4b823eac4441efff10b1c303c8f49f before 72e28774e9644c2bdbb4920842fbf77103a15a85; affected 7fc4da6a304bdcd3de14fc946dc2c19437a9cc5a before f0d385f6689f37a2828c686fb279121df006b4cb |
| Linux / Linux | affected 6.18.4 before 6.18.6 |
CWE
No CWE identifiers supplied.