CVE-2023-53590: sctp: add a refcnt in sctp_stream_priorities to avoid a nested loop

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-10-04 · updated 2026-06-17
Weakness: CWE-667

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.

Affected products

Linux kernel: from 5.4.226 before 5.4.235; from 5.10.158 before 5.10.173; from 5.15.82 before 5.15.100; from 6.0.12 before 6.1; from 6.1.1 before 6.1.18; from 6.2 before 6.2.5 — fixed in 5.10.173, 5.15.100, 5.4.235, 6.1, 6.1.18, 6.2.5

How to fix

Upgrade to a fixed version: Linux kernel 5.10.173, 5.15.100, 5.4.235, 6.1. Check the vendor advisory for mitigations.

References

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