Description (CNA)
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.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 34ae932a40369be6bd6ea97d66b6686361b4370d before 7438dc55c0709819b813f4778aec2c48b782990b; affected 34ae932a40369be6bd6ea97d66b6686361b4370d before ef6f9ce0a79aa23b10fc5f3b3cab3814a25aac40; affected 34ae932a40369be6bd6ea97d66b6686361b4370d before 5ae05b5eb58773cfec307ff88aff4cfd843c4cff; affected 34ae932a40369be6bd6ea97d66b6686361b4370d before 837b96d8103938e35e7d92cd9db96af914ca4fff; affected 34ae932a40369be6bd6ea97d66b6686361b4370d before 3554c214b83ec9a839ed574263a34218f372990c; affected 34ae932a40369be6bd6ea97d66b6686361b4370d before 53bce9d19b0a9d245b25cd050b81652ed974a509; affected 34ae932a40369be6bd6ea97d66b6686361b4370d before 1f30fb9166d4f15a1aa19449b9da871fe0ed4796 |
| Linux / Linux | affected 4.3; unaffected 0 before 4.3; unaffected 4.19.249 through 4.19.*; unaffected 5.4.200 through 5.4.*; unaffected 5.10.111 through 5.10.*; unaffected 5.15.34 through 5.15.*; unaffected 5.16.20 through 5.16.*; unaffected 5.17.3 through 5.17.*; unaffected 5.18 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/7438dc55c0709819b813f4778aec2c48b782990b
- https://git.kernel.org/stable/c/ef6f9ce0a79aa23b10fc5f3b3cab3814a25aac40
- https://git.kernel.org/stable/c/5ae05b5eb58773cfec307ff88aff4cfd843c4cff
- https://git.kernel.org/stable/c/837b96d8103938e35e7d92cd9db96af914ca4fff
- https://git.kernel.org/stable/c/3554c214b83ec9a839ed574263a34218f372990c
- https://git.kernel.org/stable/c/53bce9d19b0a9d245b25cd050b81652ed974a509
- https://git.kernel.org/stable/c/1f30fb9166d4f15a1aa19449b9da871fe0ed4796