GHSA-p354-hgpr-gp36 · 深刻度： unknown — In the Linux kernel, the following vulnerability has been resolved: net: openvswitch: remove...
In the Linux kernel, the following vulnerability has been resolved: net: openvswitch: remove never-working support for setting nsh fields The validation of the set(nsh(...)) action is completely wrong. It runs through the nsh_key_put_from_nlattr() function that is the same function that validates NSH keys for the flow match and the push_nsh() action. However, the set(nsh(...)) has a very different memory layout. Nested attributes in there are doubled in size in case of the masked set(). That makes proper validation impossible. There is also confusion in the code between the 'masked' flag, that says that the nested attributes are doubled in size containing both the value and the mask, and the 'is_mask' that says that the value we're parsing is the mask. This is causing kernel crash on trying to write into mask part of the match with SW_FLOW_KEY_PUT() during validation, while validate_nsh() doesn't allocate any memory for it: BUG: kernel NULL pointer dereference, address: 0000000000000018 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 1c2383067 P4D 1c2383067 PUD 20b703067 PMD 0 Oops: Oops: 0000 [#1] SMP NOPTI CPU: 8 UID: 0 Kdump: loaded Not tainted 6.17.0-rc4+ #107 PREEMPT(voluntary) RIP: 0010:nsh_key_put_from_nlattr+0x19d/0x610 [openvswitch] Call Trace: <TASK> validate_nsh+0x60/0x90 [openvswitch] validate_set.constprop.0+0x270/0x3c0 [openvswitch] __ovs_nla_copy_actions+0x477/0x860 [openvswitch] ovs_nla_copy_actions+0x8d/0x100 [openvswitch] ovs_packet_cmd_execute+0x1cc/0x310 [openvswitch] genl_family_rcv_msg_doit+0xdb/0x130 genl_family_rcv_msg+0x14b/0x220 genl_rcv_msg+0x47/0xa0 netlink_rcv_skb+0x53/0x100 genl_rcv+0x24/0x40 netlink_unicast+0x280/0x3b0 netlink_sendmsg+0x1f7/0x430 ____sys_sendmsg+0x36b/0x3a0 ___sys_sendmsg+0x87/0xd0 __sys_sendmsg+0x6d/0xd0 do_syscall_64+0x7b/0x2c0 entry_SYSCALL_64_after_hwframe+0x76/0x7e The third issue with this process is that while trying to convert the non-masked set into masked one, validate_set() copies and doubles the size of the OVS_KEY_ATTR_NSH as if it didn't have any nested attributes. It should be copying each nested attribute and doubling them in size independently. And the process must be properly reversed during the conversion back from masked to a non-masked variant during the flow dump. In the end, the only two outcomes of trying to use this action are either validation failure or a kernel crash. And if somehow someone manages to install a flow with such an action, it will most definitely not do what it is supposed to, since all the keys and the masks are mixed up. Fixing all the issues is a complex task as it requires re-writing most of the validation code. Given that and the fact that this functionality never worked since introduction, let's just remove it altogether. It's better to re-introduce it later with a proper implementation instead of trying to fix it in stable releases.
総合評価: CVE-2025-40254 は低リスク（9.4/100）。悪用される可能性が高い（EPSS 0.19%、9 パーセンタイル） 推奨対応: 総合リスクは低く緊急対応は不要です。通常の保守サイクルでパッチを適用し、CVSS / EPSS が上昇したら優先度を見直してください。
リスクは変動します。再評価に基づき、本ページの表示内容を更新しています。
EPSS は日次で悪用されやすさの相対度合いを推定します。パーセンタイルは採点済み CVE の中での相対位置（高いほど相対的に深刻）を示します。
| # | 日付 | 旧 EPSS スコア | 新 EPSS スコア | Δ（新 − 旧） |
|---|---|---|---|---|
| 1 | 2026-06-15 | 0.07% | 0.19% | +0.13% |
| 2 | 2026-05-14 | 0.05% | 0.07% | +0.02% |
| 3 | 2026-05-03 | — | 0.05% | — |
EPSS の全履歴 （全 5 件）
この CVE の CVSS 指標。
この CVE のデータセットに CVSS はありません。
GHSA-p354-hgpr-gp36 · 深刻度： unknown — In the Linux kernel, the following vulnerability has been resolved: net: openvswitch: remove...
| vendor | priority | summary | link |
|---|---|---|---|
debian
|
not yet assigned | CVE-2025-40254 not yet assigned priority: Debian including 2 source packages (linux, linux-6.1), 6 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 6. | https://security-tracker.debian.org/tracker/CVE-2025-40254 |
redhat
|
medium | — | https://access.redhat.com/security/cve/CVE-2025-40254 |
suse
|
medium | CVE-2025-40254 severity moderate: SUSE including 399 source package names (13.2-9.1:libsystemd0-254.23-1.1, 13.2-9.1:libudev1-254.23-1.1, …), 682 product×package rows across 92 product lines (Container suse/sl-micro/6.0/baremetal-os-container, Container suse/sl-micro/6.0/base-os-container, … (92 product lines)): Fixed 370, Known Affected 231, Known Not Affected 56, First Fixed 25. | https://www.suse.com/security/cve/CVE-2025-40254/ |
ubuntu
|
medium | CVE-2025-40254 medium priority: Ubuntu including 157 source packages (linux, linux-allwinner-5.19, …), 1405 status rows across 9 suites (bionic, focal, jammy, noble, plucky, questing, trusty, upstream, xenial): DNE 1010, ignored 179, released 160, needed 45, not-affected 8, pending 3. | https://ubuntu.com/security/CVE-2025-40254 |
| ベンダー | 製品 | バージョン | 生の CPE |
|---|---|---|---|
| linux | linux_kernel | >= 4.15, < 5.4.302 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 4.15, < 5.10.247 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 4.15, < 5.15.197 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 4.15, < 6.1.159 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 4.15, < 6.6.118 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 4.15, < 6.12.60 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 4.15, < 6.17.10 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| linux | linux_kernel | >= 4.15, < 6.18 | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |