{"cve":"CVE-2025-21858","nvd":{"published":"2025-03-12T10:15:18.720","modified":"2026-10-15T02:17:38.807","status":"Modified","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)->geneve_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---","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/3ce92ca990cfac88a87c61df3cc0b5880e688ecf","https://git.kernel.org/stable/c/5a0538ac6826807d6919f6aecbb8996c2865af2c","https://git.kernel.org/stable/c/788dbca056a8783ec063da3c9d49a3a71c76c283","https://git.kernel.org/stable/c/904e746b2e7fa952ab8801b303ce826a63153d78","https://git.kernel.org/stable/c/9593172d93b9f91c362baec4643003dc29802929"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:00:17.429720821+00:00"},"epss":{"cve":"CVE-2025-21858","score":0.0025,"percentile":0.16171,"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."]}