CVE-2025-21926
In the Linux kernel, the following vulnerability has been resolved: net: gso: fix ownership in __udp_gso_segment In __udp_gso_segment the skb destructor is removed before segmenting the skb but the socket reference is kept as-is.
Does this matter?
Lower severity and a low EPSS score (0.24%). Track it; it rarely justifies an emergency change on its own.
Description
In the Linux kernel, the following vulnerability has been resolved: net: gso: fix ownership in __udp_gso_segment In __udp_gso_segment the skb destructor is removed before segmenting the skb but the socket reference is kept as-is. This is an issue if the original skb is later orphaned as we can hit the following bug: kernel BUG at ./include/linux/skbuff.h:3312! (skb_orphan) RIP: 0010:ip_rcv_core+0x8b2/0xca0 Call Trace: ip_rcv+0xab/0x6e0 __netif_receive_skb_one_core+0x168/0x1b0 process_backlog+0x384/0x1100 __napi_poll.constprop.0+0xa1/0x370 net_rx_action+0x925/0xe50 The above can happen following a sequence of events when using OpenVSwitch, when an OVS_ACTION_ATTR_USERSPACE action precedes an OVS_ACTION_ATTR_OUTPUT action: 1. OVS_ACTION_ATTR_USERSPACE is handled (in do_execute_actions): the skb goes through queue_gso_packets and then __udp_gso_segment, where its destructor is removed. 2. The segments' data are copied and sent to userspace. 3. OVS_ACTION_ATTR_OUTPUT is handled (in do_execute_actions) and the same original skb is sent to its path. 4. If it later hits skb_orphan, we hit the bug. Fix this by also removing the reference to the socket in __udp_gso_segment.
- CVSS 3.1
- 5.5 MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.24% probability · 15th percentile
- CISA KEV
- Not listed
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/01a83237644d6822bc7df2c5564fc81b0df84358Patch
- https://git.kernel.org/stable/c/084819b0d8b1bd433b90142371eb9450d657f8caPatch
- https://git.kernel.org/stable/c/455217ac9db0cf9349b3933664355e907bb1a569Patch
- https://git.kernel.org/stable/c/9f28205ddb76e86cac418332e952241d85fed0dcPatch
- https://git.kernel.org/stable/c/a2d1cca955ed34873e524cc2e6e885450d262f05Patch
- https://git.kernel.org/stable/c/c32da44cc9298eaa6109e3fc2c2b4e07cc4bf11bPatch
- https://git.kernel.org/stable/c/e8db70537878e1bb3fd83e5abcc6feefc0587828Patch
- https://git.kernel.org/stable/c/ee01b2f2d7d0010787c2343463965bbc283a497fPatch
- https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html
- https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.