{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2025-21678 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2025-21678 is a high-severity use after free vulnerability in Linux kernel, published on 31 Jan 2025. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2025-21678 and fix it if it is affected.\n\nWhat it is: CVE-2025-21678 is a high-severity use after free vulnerability in Linux kernel, published on 31 Jan 2025. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2025-21678 in the wild and no public exploit code.\n\nAffected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2025-21678/ (Markdown: https://insights.sbomify.com/CVE-2025-21678/index.md)","id":"CVE-2025-21678","markdown":"https://insights.sbomify.com/CVE-2025-21678/index.md","name":"CVE-2025-21678","record":{"aliases":["BELL-CVE-2025-21678","DEBIAN-CVE-2025-21678","GHSA-52qf-338q-xphv","UBUNTU-CVE-2025-21678"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel GTP","requires_auth":"low_privilege","summary":"A use-after-free vulnerability in the Linux kernel GTP module allows local attackers to cause a system crash by deleting network namespaces.","user_interaction":"not_required","vuln_class":"use_after_free"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":7.8,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\ngtp: Destroy device along with udp socket's netns dismantle.\n\ngtp_newlink() links the device to a list in dev_net(dev) instead of\nsrc_net, where a udp tunnel socket is created.\n\nEven when src_net is removed, the device stays alive on dev_net(dev).\nThen, removing src_net triggers the splat below. [0]\n\nIn this example, gtp0 is created in ns2, and the udp socket is created\nin ns1.\n\n  ip netns add ns1\n  ip netns add ns2\n  ip -n ns1 link add netns ns2 name gtp0 type gtp role sgsn\n  ip netns del ns1\n\nLet's link the device to the socket's netns instead.\n\nNow, gtp_net_exit_batch_rtnl() needs another netdev iteration to remove\nall gtp devices in the netns.\n\n[0]:\nref_tracker: net notrefcnt@000000003d6e7d05 has 1/2 users at\n     sk_alloc (./include/net/net_namespace.h:345 net/core/sock.c:2236)\n     inet_create (net/ipv4/af_inet.c:326 net/ipv4/af_inet.c:252)\n     __sock_create (net/socket.c:1558)\n     udp_sock_create4 (net/ipv4/udp_tunnel_core.c:18)\n     gtp_create_sock (./include/net/udp_tunnel.h:59 drivers/net/gtp.c:1423)\n     gtp_create_sockets (drivers/net/gtp.c:1447)\n     gtp_newlink (drivers/net/gtp.c:1507)\n     rtnl_newlink (net/core/rtnetlink.c:3786 net/core/rtnetlink.c:3897 net/core/rtnetlink.c:4012)\n     rtnetlink_rcv_msg (net/core/rtnetlink.c:6922)\n     netlink_rcv_skb (net/netlink/af_netlink.c:2542)\n     netlink_unicast (net/netlink/af_netlink.c:1321 net/netlink/af_netlink.c:1347)\n     netlink_sendmsg (net/netlink/af_netlink.c:1891)\n     ____sys_sendmsg (net/socket.c:711 net/socket.c:726 net/socket.c:2583)\n     ___sys_sendmsg (net/socket.c:2639)\n     __sys_sendmsg (net/socket.c:2669)\n     do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)\n\nWARNING: CPU: 1 PID: 60 at lib/ref_tracker.c:179 ref_tracker_dir_exit (lib/ref_tracker.c:179)\nModules linked in:\nCPU: 1 UID: 0 PID: 60 Comm: kworker/u16:2 Not tainted 6.13.0-rc5-00147-g4c1224501e9d #5\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014\nWorkqueue: netns cleanup_net\nRIP: 0010:ref_tracker_dir_exit (lib/ref_tracker.c:179)\nCode: 00 00 00 fc ff df 4d 8b 26 49 bd 00 01 00 00 00 00 ad de 4c 39 f5 0f 85 df 00 00 00 48 8b 74 24 08 48 89 df e8 a5 cc 12 02 90 \u003c0f\u003e 0b 90 48 8d 6b 44 be 04 00 00 00 48 89 ef e8 80 de 67 ff 48 89\nRSP: 0018:ff11000009a07b60 EFLAGS: 00010286\nRAX: 0000000000002bd3 RBX: ff1100000f4e1aa0 RCX: 1ffffffff0e40ac6\nRDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8423ee3c\nRBP: ff1100000f4e1af0 R08: 0000000000000001 R09: fffffbfff0e395ae\nR10: 0000000000000001 R11: 0000000000036001 R12: ff1100000f4e1af0\nR13: dead000000000100 R14: ff1100000f4e1af0 R15: dffffc0000000000\nFS:  0000000000000000(0000) GS:ff1100006ce80000(0000) knlGS:0000000000000000\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 00007f9b2464bd98 CR3: 0000000005286005 CR4: 0000000000771ef0\nDR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\nDR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400\nPKRU: 55555554\nCall Trace:\n \u003cTASK\u003e\n ? __warn (kernel/panic.c:748)\n ? ref_tracker_dir_exit (lib/ref_tracker.c:179)\n ? report_bug (lib/bug.c:201 lib/bug.c:219)\n ? handle_bug (arch/x86/kernel/traps.c:285)\n ? exc_invalid_op (arch/x86/kernel/traps.c:309 (discriminator 1))\n ? asm_exc_invalid_op (./arch/x86/include/asm/idtentry.h:621)\n ? _raw_spin_unlock_irqrestore (./arch/x86/include/asm/irqflags.h:42 ./arch/x86/include/asm/irqflags.h:97 ./arch/x86/include/asm/irqflags.h:155 ./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194)\n ? ref_tracker_dir_exit (lib/ref_tracker.c:179)\n ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:158)\n ? kfree (mm/slub.c:4613 mm/slub.c:4761)\n net_free (net/core/net_namespace.c:476 net/core/net_namespace.c:467)\n cleanup_net (net/core/net_namespace.c:664 (discriminator 3))\n process_one_work (kernel/workqueue.c:3229)\n worker_thread (kernel/workqueue.c:3304 kernel/workqueue.c:3391\n---truncated---","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"gtp: Destroy device along with udp socket's netns dismantle.","id":"CVE-2025-21678","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"use_after_free","year":"2025"},"n_packages":0,"n_references":7,"next":{"headline":"btrfs: add the missing error handling inside get_canonical_dev_path","id":"CVE-2025-21679"},"packages":[],"prev":{"headline":"pfcp: Destroy device along with udp socket's netns dismantle.","id":"CVE-2025-21677"},"products":["Linux"],"published":"2025-01-31","related":[{"cvss_score":8.8,"headline":"Linux Kernel Out-of-Bounds Write","id":"CVE-2026-53266","kev_date_added":"2026-09-18","published":"2026-06-25"},{"cvss_score":8.8,"headline":"Linux Kernel Improper Input Validation","id":"CVE-2013-6282","kev_date_added":"2022-09-15","published":"2013-11-19"},{"cvss_score":8.4,"headline":"Linux Kernel Heap-Based Buffer Overflow","id":"CVE-2022-0185","kev_date_added":"2024-08-21","published":"2022-02-11"},{"cvss_score":8.4,"headline":"Linux Kernel Privilege Escalation","id":"CVE-2013-2094","kev_date_added":"2022-09-15","published":"2013-05-14"},{"cvss_score":7.8,"headline":"Linux Kernel Unspecified","id":"CVE-2026-53362","kev_date_added":"2026-08-27","published":"2026-07-04"},{"cvss_score":7.8,"headline":"Linux Kernel Missing Initialization of a Variable","id":"CVE-2026-46300","kev_date_added":"2026-10-28","published":"2026-05-23"},{"cvss_score":7.8,"headline":"Linux Kernel Race Condition","id":"CVE-2025-39964","kev_date_added":"2026-09-18","published":"2025-10-13"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-10-15","vendors":["Linux"]},"summary":"A use-after-free vulnerability in the Linux kernel GTP module allows local attackers to cause a system crash by deleting network namespaces.","url":"https://insights.sbomify.com/CVE-2025-21678/"}