CVE-2025-38614
What it is
In the Linux kernel, the following vulnerability has been resolved: eventpoll: Fix semi-unbounded recursion Ensure that epoll instances can never form a graph deeper than EP_MAX_NESTS+1 links. Currently, ep_loop_check_proc() ensures that the graph is loop-free and does some recursion depth checks, but those recursion depth checks don't limit the depth of the resulting tree for two reasons: - They don't look upwards in the tree. - If there are multiple downwards paths of different lengths, only one of the paths is actually considered for the depth check since commit 28d82dc1c4ed ("epoll: limit paths"). Essentially, the current recursion depth check in ep_loop_check_proc() just serves to prevent it from recursing too deeply while checking for loops. A more thorough check is done in reverse_path_check() after the new graph edge has already been created; this checks, among other things, that no paths going upwards from any non-epoll file with a length of more than 5 edges exist. However, this check does not apply to non-epoll files. As a result, it is possible to recurse to a depth of at least roughly 500, tested on v6.15. (I am unsure if deeper recursion is possible; and this may have changed with commit 8c44dac8add7 ("eventpoll: Fix priority inversion problem").) To fix it: 1. In ep_loop_check_proc(), note the subtree depth of each visited node, and use subtree depths for the total depth calculation even when a subtree has already been visited. 2. Add ep_get_upwards_depth_proc() for similarly determining the maximum depth of an upwards walk. 3. In ep_loop_check(), use these values to limit the total path length between epoll nodes to EP_MAX_NESTS edges.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.
- Exploit odds
- 0.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.2% in the next 30 days (EPSS).
- Severity: 7.8 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Weakness
- CWE-674
- Record status
- Modified
Affected
- Linux Kernel < 2.6.33
- Linux Kernel < 2.6.34
- Linux Kernel < 2.6.35
- Linux Kernel < 2.6.36
- Linux Kernel < 2.6.38
- Linux Kernel < 5.15.190
- Linux Kernel < 6.1.149
- Linux Kernel < 6.6.103
Attack profile CVSS 3.1 · 7.8
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2025-38614.md and follow it. Check whether this project is affected by CVE-2025-38614. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/1b13b033062824495554e836a1ff5f85ccf6b039
- https://git.kernel.org/stable/c/2a0c0c974bea9619c6f41794775ae4b97530e0e6
- https://git.kernel.org/stable/c/3542c90797bc3ab83ebab54b737d751cf3682036
- https://git.kernel.org/stable/c/71379495ab70eaba19224bd71b5b9b399eb85e04
- https://git.kernel.org/stable/c/7a2125962c42d5336ca0495a9ce4cb38a63e9161
- https://git.kernel.org/stable/c/ea5f97dbdcb1651581a22bd10afd2f0dd9dc11d6
- https://git.kernel.org/stable/c/f2e467a48287c868818085aa35389a224d226732
References
- https://git.kernel.org/stable/c/1b13b033062824495554e836a1ff5f85ccf6b039
- https://git.kernel.org/stable/c/2a0c0c974bea9619c6f41794775ae4b97530e0e6
- https://git.kernel.org/stable/c/3542c90797bc3ab83ebab54b737d751cf3682036
- https://git.kernel.org/stable/c/71379495ab70eaba19224bd71b5b9b399eb85e04
- https://git.kernel.org/stable/c/7a2125962c42d5336ca0495a9ce4cb38a63e9161
- https://git.kernel.org/stable/c/ea5f97dbdcb1651581a22bd10afd2f0dd9dc11d6
- https://git.kernel.org/stable/c/f2e467a48287c868818085aa35389a224d226732
- https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-032379.html
- https://cert-portal.siemens.com/productcert/html/ssa-082556.html
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html