CVE-2023-53590 sctp: add a refcnt in sctp_stream_priorities to avoid a nested loop
A nested loop in the Linux kernel SCTP implementation can cause a CPU soft lockup, leading to 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-2023-53590?
CVE-2023-53590 is a medium-severity denial of service vulnerability in Linux kernel, published on 4 Oct 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:
sctp: add a refcnt in sctp_stream_priorities to avoid a nested loop
With this refcnt added in sctp_stream_priorities, we don't need to traverse all streams to check if the prio is used by other streams when freeing one stream's prio in sctp_sched_prio_free_sid(). This can avoid a nested loop (up to 65535 * 65535), which may cause a stuck as Ying reported:
watchdog: BUG: soft lockup - CPU#23 stuck for 26s! [ksoftirqd/23:136] Call Trace: <TASK> sctp_sched_prio_free_sid+0xab/0x100 [sctp] sctp_stream_free_ext+0x64/0xa0 [sctp] sctp_stream_free+0x31/0x50 [sctp] sctp_association_free+0xa5/0x200 [sctp]
Note that it doesn't need to use refcount_t type for this counter, as its accessing is always protected under the sock lock.
v1->v2: - add a check in sctp_sched_prio_set to avoid the possible prio_head refcnt overflow.
Weakness: CWE-667
Which versions are affected by CVE-2023-53590?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2023-53590?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2023-53590 being exploited?
There is no known exploitation of CVE-2023-53590 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2023-53590, DEBIAN-CVE-2023-53590, GHSA-h343-797x-8cg9, UBUNTU-CVE-2023-53590.