CVE-2022-49086
What it is
In the Linux kernel, the following vulnerability has been resolved: net: openvswitch: fix leak of nested actions While parsing user-provided actions, openvswitch module may dynamically allocate memory and store pointers in the internal copy of the actions. So this memory has to be freed while destroying the actions. Currently there are only two such actions: ct() and set(). However, there are many actions that can hold nested lists of actions and ovs_nla_free_flow_actions() just jumps over them leaking the memory. For example, removal of the flow with the following actions will lead to a leak of the memory allocated by nf_ct_tmpl_alloc(): actions:clone(ct(commit),0) Non-freed set() action may also leak the 'dst' structure for the tunnel info including device references. Under certain conditions with a high rate of flow rotation that may cause significant memory leak problem (2MB per second in reporter's case). The problem is also hard to mitigate, because the user doesn't have direct control over the datapath flows generated by OVS. Fix that by iterating over all the nested actions and freeing everything that needs to be freed recursively. New build time assertion should protect us from this problem if new actions will be added in the future. Unfortunately, openvswitch module doesn't use NLA_F_NESTED, so all attributes has to be explicitly checked. sample() and clone() actions are mixing extra attributes into the user-provided action list. That prevents some code generalization too.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of service disruption.
- Exploit odds
- 0.3% 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: 0.3% in the next 30 days (EPSS).
- Severity: 5.5 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.3% · EPSS, next 30 days
- Weakness
- CWE-401
- Record status
- Analyzed
Affected
- Linux Kernel < 4.19.249
- Linux Kernel < 5.4.200
- Linux Kernel < 5.10.111
- Linux Kernel < 5.15.34
- Linux Kernel < 5.16.20
- Linux Kernel < 5.17.3
- Linux Kernel 5.18
Attack profile CVSS 3.1 · 5.5
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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-2022-49086.md and follow it. Check whether this project is affected by CVE-2022-49086. 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/1f30fb9166d4f15a1aa19449b9da871fe0ed4796
- https://git.kernel.org/stable/c/3554c214b83ec9a839ed574263a34218f372990c
- https://git.kernel.org/stable/c/53bce9d19b0a9d245b25cd050b81652ed974a509
- https://git.kernel.org/stable/c/5ae05b5eb58773cfec307ff88aff4cfd843c4cff
- https://git.kernel.org/stable/c/7438dc55c0709819b813f4778aec2c48b782990b
- https://git.kernel.org/stable/c/837b96d8103938e35e7d92cd9db96af914ca4fff
- https://git.kernel.org/stable/c/ef6f9ce0a79aa23b10fc5f3b3cab3814a25aac40
References
- https://git.kernel.org/stable/c/1f30fb9166d4f15a1aa19449b9da871fe0ed4796
- https://git.kernel.org/stable/c/3554c214b83ec9a839ed574263a34218f372990c
- https://git.kernel.org/stable/c/53bce9d19b0a9d245b25cd050b81652ed974a509
- https://git.kernel.org/stable/c/5ae05b5eb58773cfec307ff88aff4cfd843c4cff
- https://git.kernel.org/stable/c/7438dc55c0709819b813f4778aec2c48b782990b
- https://git.kernel.org/stable/c/837b96d8103938e35e7d92cd9db96af914ca4fff
- https://git.kernel.org/stable/c/ef6f9ce0a79aa23b10fc5f3b3cab3814a25aac40