{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2025-21858 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2025-21858 is a high-severity use after free vulnerability in Linux kernel, published on 12 Mar 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-2025-21858 and fix it if it is affected.\n\nWhat it is: CVE-2025-21858 is a high-severity use after free vulnerability in Linux kernel, published on 12 Mar 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-2025-21858 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-2025-21858/ (Markdown: https://insights.sbomify.com/CVE-2025-21858/index.md)","id":"CVE-2025-21858","markdown":"https://insights.sbomify.com/CVE-2025-21858/index.md","name":"CVE-2025-21858","record":{"aliases":["AZL-58515","AZL-58584","BELL-CVE-2025-21858","DEBIAN-CVE-2025-21858","GHSA-r9xq-fh23-wm6f","ROOT-OS-UBUNTU-2404-CVE-2025-21858","UBUNTU-CVE-2025-21858"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["code_execution","privilege_escalation"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A use-after-free in the Linux kernel's GENEVE driver allows local attackers to potentially execute code or escalate privileges via crafted network namespace operations.","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":[{"id":"CWE-416","name":"Use After Free"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\ngeneve: Fix use-after-free in geneve_find_dev().\n\nsyzkaller reported a use-after-free in geneve_find_dev() [0]\nwithout repro.\n\ngeneve_configure() links struct geneve_dev.next to\nnet_generic(net, geneve_net_id)-\u003egeneve_list.\n\nThe net here could differ from dev_net(dev) if IFLA_NET_NS_PID,\nIFLA_NET_NS_FD, or IFLA_TARGET_NETNSID is set.\n\nWhen dev_net(dev) is dismantled, geneve_exit_batch_rtnl() finally\ncalls unregister_netdevice_queue() for each dev in the netns,\nand later the dev is freed.\n\nHowever, its geneve_dev.next is still linked to the backend UDP\nsocket netns.\n\nThen, use-after-free will occur when another geneve dev is created\nin the netns.\n\nLet's call geneve_dellink() instead in geneve_destroy_tunnels().\n\n[0]:\nBUG: KASAN: slab-use-after-free in geneve_find_dev drivers/net/geneve.c:1295 [inline]\nBUG: KASAN: slab-use-after-free in geneve_configure+0x234/0x858 drivers/net/geneve.c:1343\nRead of size 2 at addr ffff000054d6ee24 by task syz.1.4029/13441\n\nCPU: 1 UID: 0 PID: 13441 Comm: syz.1.4029 Not tainted 6.13.0-g0ad9617c78ac #24 dc35ca22c79fb82e8e7bc5c9c9adafea898b1e3d\nHardware name: linux,dummy-virt (DT)\nCall trace:\n show_stack+0x38/0x50 arch/arm64/kernel/stacktrace.c:466 (C)\n __dump_stack lib/dump_stack.c:94 [inline]\n dump_stack_lvl+0xbc/0x108 lib/dump_stack.c:120\n print_address_description mm/kasan/report.c:378 [inline]\n print_report+0x16c/0x6f0 mm/kasan/report.c:489\n kasan_report+0xc0/0x120 mm/kasan/report.c:602\n __asan_report_load2_noabort+0x20/0x30 mm/kasan/report_generic.c:379\n geneve_find_dev drivers/net/geneve.c:1295 [inline]\n geneve_configure+0x234/0x858 drivers/net/geneve.c:1343\n geneve_newlink+0xb8/0x128 drivers/net/geneve.c:1634\n rtnl_newlink_create+0x23c/0x868 net/core/rtnetlink.c:3795\n __rtnl_newlink net/core/rtnetlink.c:3906 [inline]\n rtnl_newlink+0x1054/0x1630 net/core/rtnetlink.c:4021\n rtnetlink_rcv_msg+0x61c/0x918 net/core/rtnetlink.c:6911\n netlink_rcv_skb+0x1dc/0x398 net/netlink/af_netlink.c:2543\n rtnetlink_rcv+0x34/0x50 net/core/rtnetlink.c:6938\n netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline]\n netlink_unicast+0x618/0x838 net/netlink/af_netlink.c:1348\n netlink_sendmsg+0x5fc/0x8b0 net/netlink/af_netlink.c:1892\n sock_sendmsg_nosec net/socket.c:713 [inline]\n __sock_sendmsg net/socket.c:728 [inline]\n ____sys_sendmsg+0x410/0x6f8 net/socket.c:2568\n ___sys_sendmsg+0x178/0x1d8 net/socket.c:2622\n __sys_sendmsg net/socket.c:2654 [inline]\n __do_sys_sendmsg net/socket.c:2659 [inline]\n __se_sys_sendmsg net/socket.c:2657 [inline]\n __arm64_sys_sendmsg+0x12c/0x1c8 net/socket.c:2657\n __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]\n invoke_syscall+0x90/0x278 arch/arm64/kernel/syscall.c:49\n el0_svc_common+0x13c/0x250 arch/arm64/kernel/syscall.c:132\n do_el0_svc+0x54/0x70 arch/arm64/kernel/syscall.c:151\n el0_svc+0x4c/0xa8 arch/arm64/kernel/entry-common.c:744\n el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:762\n el0t_64_sync+0x198/0x1a0 arch/arm64/kernel/entry.S:600\n\nAllocated by task 13247:\n kasan_save_stack mm/kasan/common.c:47 [inline]\n kasan_save_track+0x30/0x68 mm/kasan/common.c:68\n kasan_save_alloc_info+0x44/0x58 mm/kasan/generic.c:568\n poison_kmalloc_redzone mm/kasan/common.c:377 [inline]\n __kasan_kmalloc+0x84/0xa0 mm/kasan/common.c:394\n kasan_kmalloc include/linux/kasan.h:260 [inline]\n __do_kmalloc_node mm/slub.c:4298 [inline]\n __kmalloc_node_noprof+0x2a0/0x560 mm/slub.c:4304\n __kvmalloc_node_noprof+0x9c/0x230 mm/util.c:645\n alloc_netdev_mqs+0xb8/0x11a0 net/core/dev.c:11470\n rtnl_create_link+0x2b8/0xb50 net/core/rtnetlink.c:3604\n rtnl_newlink_create+0x19c/0x868 net/core/rtnetlink.c:3780\n __rtnl_newlink net/core/rtnetlink.c:3906 [inline]\n rtnl_newlink+0x1054/0x1630 net/core/rtnetlink.c:4021\n rtnetlink_rcv_msg+0x61c/0x918 net/core/rtnetlink.c:6911\n netlink_rcv_skb+0x1dc/0x398 net/netlink/af_netlink.c:2543\n rtnetlink_rcv+0x34/0x50 net/core/rtnetlink.c:6938\n netlink_unicast_kernel net/netlink/af_n\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":"geneve: Fix use-after-free in geneve_find_dev().","id":"CVE-2025-21858","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":8,"next":{"headline":"USB: gadget: f_midi: f_midi_complete to call queue_work","id":"CVE-2025-21859"},"packages":[],"prev":{"headline":"net/sched: cls_api: fix error handling causing NULL dereference","id":"CVE-2025-21857"},"products":["Linux"],"published":"2025-03-12","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":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-10-15","vendors":["Linux"]},"summary":"A use-after-free in the Linux kernel's GENEVE driver allows local attackers to potentially execute code or escalate privileges via crafted network namespace operations.","url":"https://insights.sbomify.com/CVE-2025-21858/"}