{"id":"CVE-2025-21926","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: gso: fix ownership in __udp_gso_segment\n\nIn __udp_gso_segment the skb destructor is removed before segmenting the\nskb but the socket reference is kept as-is","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: gso: fix ownership in __udp_gso_segment\n\nIn __udp_gso_segment the skb destructor is removed before segmenting the\nskb but the socket reference is kept as-is. This …","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 4.18, < 5.4.291","linux_kernel >= 5.5, < 5.10.235","linux_kernel >= 5.11, < 5.15.179","linux_kernel >= 5.16, < 6.1.131","linux_kernel >= 6.2, < 6.6.83","linux_kernel >= 6.7, < 6.12.19","linux_kernel >= 6.13, < 6.13.7","linux_kernel = 6.14"],"patched":["linux_kernel 6.13.7"],"published":"2025-04-01","updated":"2026-07-14","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2025-21926","references":[{"url":"https://git.kernel.org/stable/c/01a83237644d6822bc7df2c5564fc81b0df84358","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/084819b0d8b1bd433b90142371eb9450d657f8ca","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/455217ac9db0cf9349b3933664355e907bb1a569","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/9f28205ddb76e86cac418332e952241d85fed0dc","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a2d1cca955ed34873e524cc2e6e885450d262f05","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/c32da44cc9298eaa6109e3fc2c2b4e07cc4bf11b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e8db70537878e1bb3fd83e5abcc6feefc0587828","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ee01b2f2d7d0010787c2343463965bbc283a497f","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-019113.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","cve.org"],"epss":0.00239,"epssPercentile":0.15198,"ingestedAt":"2026-07-14T13:36:56.091Z","slug":"CVE-2025-21926","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnet: gso: fix ownership in __udp_gso_segment\n\nIn __udp_gso_segment the skb destructor is removed before segmenting the\nskb but the socket reference is kept as-is. This is an issue if the\noriginal skb is later orphaned as we can hit the following bug:\n\n  kernel BUG at ./include/linux/skbuff.h:3312!  (skb_orphan)\n  RIP: 0010:ip_rcv_core+0x8b2/0xca0\n  Call Trace:\n   ip_rcv+0xab/0x6e0\n   __netif_receive_skb_one_core+0x168/0x1b0\n   process_backlog+0x384/0x1100\n   __napi_poll.constprop.0+0xa1/0x370\n   net_rx_action+0x925/0xe50\n\nThe above can happen following a sequence of events when using\nOpenVSwitch, when an OVS_ACTION_ATTR_USERSPACE action precedes an\nOVS_ACTION_ATTR_OUTPUT action:\n\n1. OVS_ACTION_ATTR_USERSPACE is handled (in do_execute_actions): the skb\n   goes through queue_gso_packets and then __udp_gso_segment, where its\n   destructor is removed.\n2. The segments' data are copied and sent to userspace.\n3. OVS_ACTION_ATTR_OUTPUT is handled (in do_execute_actions) and the\n   same original skb is sent to its path.\n4. If it later hits skb_orphan, we hit the bug.\n\nFix this by also removing the reference to the socket in\n__udp_gso_segment.\n\n## Affected\n\n- `linux_kernel >= 4.18, < 5.4.291`\n- `linux_kernel >= 5.5, < 5.10.235`\n- `linux_kernel >= 5.11, < 5.15.179`\n- `linux_kernel >= 5.16, < 6.1.131`\n- `linux_kernel >= 6.2, < 6.6.83`\n- `linux_kernel >= 6.7, < 6.12.19`\n- `linux_kernel >= 6.13, < 6.13.7`\n- `linux_kernel = 6.14`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.13.7`","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}