devlink: fix devlink_rel reference leak when notify work is pending
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 6.12.113, 6.18.57, 7.2.11
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
In the Linux kernel, the following vulnerability has been resolved: devlink: fix devlink_rel reference leak when notify work is pending devlink_rel_nested_in_notify_work_schedule() takes a reference on the devlink_rel for the notify work and then queues the work, ignoring the return value of schedule_delayed_work(). If the work is already pending, nothing new is queued, the work runs only once and drops only one reference, so the extra one is leaked together with the devlink_rel and its index in devlink_rels. This is easy to hit. devl_register() of a nested instance queues the work, and if the instance is unregistered before the work has run, devlink_rel_put() queues it again while it is still pending. The work also keeps rescheduling itself for as long as the parent devlink lock cannot be taken, which widens the window. Registering and unregistering a nested devlink instance 100 times while holding the parent lock leaks all 100 devlink_rel objects. The reschedule path in devlink_rel_nested_in_notify_work() has the same problem: if the work was queued again while it was running, the reference it holds is never dropped. Drop the reference in both places when the work was already pending. The pending work holds its own reference, so this can not be the last one.
Timeline
- CVE published
- First seen by cve.now
Affected versions
- Linux Linux
From c137743bce02b18c1537d4681aa515f7b80bf0a8 · fixed in 8c7830e0120e6e1f5084212fd5b79b3092496f87; From c137743bce02b18c1537d4681aa515f7b80bf0a8 · fixed in 8de57bfec3825effb57fe4d25da98ec3b8fda4c6; From c137743bce02b18c1537d4681aa515f7b80bf0a8 · fixed in dc2e787b5fb474241c8a6d18fdacb44adc6d571f; From c137743bce02b18c1537d4681aa515f7b80bf0a8 · fixed in c5381ae1cd1481cc431c2bd79460472c6f1d3ce3
- Linux Linux
6.7
- KernelLinux
From 6.7.0 · fixed in 6.12.113; From 6.13.0 · fixed in 6.18.57; From 6.19.0 · fixed in 7.2.11