CVE-2025-23154 io_uring/net: fix io_req_post_cqe abuse by send bundle
A logic error in the Linux kernel's io_uring subsystem allows triggering a kernel warning via send bundles, potentially leading to 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-2025-23154?
CVE-2025-23154 is a medium-severity vulnerability in Linux kernel, published on 1 May 2025. 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:
io_uring/net: fix io_req_post_cqe abuse by send bundle
[ 114.987980][ T5313] WARNING: CPU: 6 PID: 5313 at io_uring/io_uring.c:872 io_req_post_cqe+0x12e/0x4f0 [ 114.991597][ T5313] RIP: 0010:io_req_post_cqe+0x12e/0x4f0 [ 115.001880][ T5313] Call Trace: [ 115.002222][ T5313] <TASK> [ 115.007813][ T5313] io_send+0x4fe/0x10f0 [ 115.009317][ T5313] io_issue_sqe+0x1a6/0x1740 [ 115.012094][ T5313] io_wq_submit_work+0x38b/0xed0 [ 115.013223][ T5313] io_worker_handle_work+0x62a/0x1600 [ 115.013876][ T5313] io_wq_worker+0x34f/0xdf0
As the comment states, io_req_post_cqe() should only be used by multishot requests, i.e. REQ_F_APOLL_MULTISHOT, which bundled sends are not. Add a flag signifying whether a request wants to post multiple CQEs. Eventually REQ_F_APOLL_MULTISHOT should imply the new flag, but that's left out for simplicity.
Which versions are affected by CVE-2025-23154?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2025-23154?
Apply the vendor's patch.
Is CVE-2025-23154 being exploited?
There is no known exploitation of CVE-2025-23154 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2025-23154, DEBIAN-CVE-2025-23154, GHSA-f6mf-84fx-cph2, UBUNTU-CVE-2025-23154.