CVE-2024-46735 ublk_drv: fix NULL pointer dereference in ublk_ctrl_start_recovery()
A local attacker can trigger a kernel crash by submitting duplicate recovery commands to the ublk driver, causing a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-46735?
CVE-2024-46735 is a medium-severity vulnerability in Linux kernel, published on 18 Sep 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
ublk_drv: fix NULL pointer dereference in ublk_ctrl_start_recovery()
When two UBLK_CMD_START_USER_RECOVERY commands are submitted, the first one sets 'ubq->ubq_daemon' to NULL, and the second one triggers WARN in ublk_queue_reinit() and subsequently a NULL pointer dereference issue.
Fix it by adding the check in ublk_ctrl_start_recovery() and return immediately in case of zero 'ub->nr_queues_ready'.
BUG: kernel NULL pointer dereference, address: 0000000000000028 RIP: 0010:ublk_ctrl_start_recovery.constprop.0+0x82/0x180 Call Trace: <TASK> ? __die+0x20/0x70 ? page_fault_oops+0x75/0x170 ? exc_page_fault+0x64/0x140 ? asm_exc_page_fault+0x22/0x30 ? ublk_ctrl_start_recovery.constprop.0+0x82/0x180 ublk_ctrl_uring_cmd+0x4f7/0x6c0 ? pick_next_task_idle+0x26/0x40 io_uring_cmd+0x9a/0x1b0 io_issue_sqe+0x193/0x3f0 io_wq_submit_work+0x9b/0x390 io_worker_handle_work+0x165/0x360 io_wq_worker+0xcb/0x2f0 ? finish_task_switch.isra.0+0x203/0x290 ? finish_task_switch.isra.0+0x203/0x290 ? __pfx_io_wq_worker+0x10/0x10 ret_from_fork+0x2d/0x50 ? __pfx_io_wq_worker+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK>
Weakness: CWE-476
Which versions are affected by CVE-2024-46735?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-46735?
Apply the vendor's patch.
Is CVE-2024-46735 being exploited?
There is no known exploitation of CVE-2024-46735 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2024-46735, DEBIAN-CVE-2024-46735, GHSA-h642-rg9x-ww4c, UBUNTU-CVE-2024-46735.