{"cve":"CVE-2025-21867","nvd":{"published":"2025-03-27T14:15:47.750","modified":"2026-10-15T02:17:40.617","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf, test_run: Fix use-after-free issue in eth_skb_pkt_type()\n\nKMSAN reported a use-after-free issue in eth_skb_pkt_type()[1]. The\ncause of the issue was that eth_skb_pkt_type() accessed skb's data\nthat didn't contain an Ethernet header. This occurs when\nbpf_prog_test_run_xdp() passes an invalid value as the user_data\nargument to bpf_test_init().\n\nFix this by returning an error when user_data is less than ETH_HLEN in\nbpf_test_init(). Additionally, remove the check for \"if (user_size >\nsize)\" as it is unnecessary.\n\n[1]\nBUG: KMSAN: use-after-free in eth_skb_pkt_type include/linux/etherdevice.h:627 [inline]\nBUG: KMSAN: use-after-free in eth_type_trans+0x4ee/0x980 net/ethernet/eth.c:165\n eth_skb_pkt_type include/linux/etherdevice.h:627 [inline]\n eth_type_trans+0x4ee/0x980 net/ethernet/eth.c:165\n __xdp_build_skb_from_frame+0x5a8/0xa50 net/core/xdp.c:635\n xdp_recv_frames net/bpf/test_run.c:272 [inline]\n xdp_test_run_batch net/bpf/test_run.c:361 [inline]\n bpf_test_run_xdp_live+0x2954/0x3330 net/bpf/test_run.c:390\n bpf_prog_test_run_xdp+0x148e/0x1b10 net/bpf/test_run.c:1318\n bpf_prog_test_run+0x5b7/0xa30 kernel/bpf/syscall.c:4371\n __sys_bpf+0x6a6/0xe20 kernel/bpf/syscall.c:5777\n __do_sys_bpf kernel/bpf/syscall.c:5866 [inline]\n __se_sys_bpf kernel/bpf/syscall.c:5864 [inline]\n __x64_sys_bpf+0xa4/0xf0 kernel/bpf/syscall.c:5864\n x64_sys_call+0x2ea0/0x3d90 arch/x86/include/generated/asm/syscalls_64.h:322\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0xd9/0x1d0 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nUninit was created at:\n free_pages_prepare mm/page_alloc.c:1056 [inline]\n free_unref_page+0x156/0x1320 mm/page_alloc.c:2657\n __free_pages+0xa3/0x1b0 mm/page_alloc.c:4838\n bpf_ringbuf_free kernel/bpf/ringbuf.c:226 [inline]\n ringbuf_map_free+0xff/0x1e0 kernel/bpf/ringbuf.c:235\n bpf_map_free kernel/bpf/syscall.c:838 [inline]\n bpf_map_free_deferred+0x17c/0x310 kernel/bpf/syscall.c:862\n process_one_work kernel/workqueue.c:3229 [inline]\n process_scheduled_works+0xa2b/0x1b60 kernel/workqueue.c:3310\n worker_thread+0xedf/0x1550 kernel/workqueue.c:3391\n kthread+0x535/0x6b0 kernel/kthread.c:389\n ret_from_fork+0x6e/0x90 arch/x86/kernel/process.c:147\n ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244\n\nCPU: 1 UID: 0 PID: 17276 Comm: syz.1.16450 Not tainted 6.12.0-05490-g9bb88c659673 #8\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-3.fc41 04/01/2014","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":["CWE-416"],"references":["https://git.kernel.org/stable/c/1a9e1284e87d59b1303b69d1808d310821d6e5f7","https://git.kernel.org/stable/c/6b3d638ca897e099fa99bd6d02189d3176f80a47","https://git.kernel.org/stable/c/972bafed67ca73ad9a56448384281eb5fd5c0ba3","https://git.kernel.org/stable/c/d56d8a23d95100b65f40438639dd82db2af81c11","https://git.kernel.org/stable/c/f615fccfc689cb48977d275ac2e391297b52392b"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:00:28.034033815+00:00"},"epss":{"cve":"CVE-2025-21867","score":0.00211,"percentile":0.11217,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}