{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-21858", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-12-29T08:45:45.780Z", "datePublished": "2025-03-12T09:42:11.343Z", "dateUpdated": "2026-08-05T11:54:57.165Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:54:57.165Z" }, "descriptions": [ { "lang": "en", "value": "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---" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerability is reached only through RTM_NEWLINK rtnetlink messages sent on an AF_NETLINK socket, requiring local system access. The geneve_list is used solely by the control plane (geneve_configure/geneve_dellink), never by the packet receive path, so no remote packet can trigger it.\nAC:L - The attacker deterministically creates both network namespaces, creates the geneve device cross-netns, destroys the device-owning netns, then creates a second geneve device to dereference the stale list entry — no race must be won and the dangling pointer persists indefinitely, allowing unhurried heap grooming of the freed 4096-byte slab object.\nPR:L - CAP_NET_ADMIN is required in the owning user namespaces of both netns, but an unprivileged user obtains exactly that with `unshare -Urn` plus a nested `unshare -n`, since both namespaces are owned by their own user_ns and the checks are ns_capable-based. The geneve module is autoloaded on demand from the same unprivileged rtnl_newlink path.\nUI:N - The full sequence is performed by the attacker's own processes via netlink and namespace file descriptors, with no action by any other user.\nS:U - The use-after-free corrupts kernel heap state and is exploited for kernel privilege escalation within the same security authority; no hypervisor, IOMMU, or other authority boundary is crossed.\nC:H - The stale list entry points into a freed kmalloc-cg-4k object the attacker can reallocate and fill, so the list traversal in geneve_find_dev() follows an attacker-controlled `next` pointer and reads arbitrary kernel addresses, with the -EBUSY/-EPERM/success result acting as a disclosure oracle.\nI:H - Later list_del()/list_add() operations on the corrupted geneve_list write through attacker-controlled prev/next pointers, yielding a classic unlink write-what-where primitive suitable for control-flow hijacking and privilege escalation.\nA:H - The bug is a confirmed slab use-after-free (KASAN slab-use-after-free reported by syzkaller) that reliably corrupts a kernel linked list, causing oops or panic even without successful exploitation." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/geneve.c" ], "versions": [ { "version": "2d07dc79fe04a43d82a346ced6bbf07bdb523f1b", "lessThan": "d5e86e27de0936f3cb0a299ce519d993e9cf3886", "status": "affected", "versionType": "git" }, { "version": "2d07dc79fe04a43d82a346ced6bbf07bdb523f1b", "lessThan": "5a0538ac6826807d6919f6aecbb8996c2865af2c", "status": "affected", "versionType": "git" }, { "version": "2d07dc79fe04a43d82a346ced6bbf07bdb523f1b", "lessThan": "f74f6560146714241c6e167b03165ee77a86e316", "status": "affected", "versionType": "git" }, { "version": "2d07dc79fe04a43d82a346ced6bbf07bdb523f1b", "lessThan": "904e746b2e7fa952ab8801b303ce826a63153d78", "status": "affected", "versionType": "git" }, { "version": "2d07dc79fe04a43d82a346ced6bbf07bdb523f1b", "lessThan": "3ce92ca990cfac88a87c61df3cc0b5880e688ecf", "status": "affected", "versionType": "git" }, { "version": "2d07dc79fe04a43d82a346ced6bbf07bdb523f1b", "lessThan": "da9b0ae47f084014b1e4b3f31f70a0defd047ff3", "status": "affected", "versionType": "git" }, { "version": "2d07dc79fe04a43d82a346ced6bbf07bdb523f1b", "lessThan": "788dbca056a8783ec063da3c9d49a3a71c76c283", "status": "affected", "versionType": "git" }, { "version": "2d07dc79fe04a43d82a346ced6bbf07bdb523f1b", "lessThan": "9593172d93b9f91c362baec4643003dc29802929", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/geneve.c" ], "versions": [ { "version": "4.2", "status": "affected" }, { "version": "0", "lessThan": "4.2", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.291", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.235", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.179", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.130", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.80", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.17", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.13.5", "lessThanOrEqual": "6.13.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.14", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.2", "versionEndExcluding": "5.4.291" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.2", "versionEndExcluding": "5.10.235" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.2", "versionEndExcluding": "5.15.179" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.2", "versionEndExcluding": "6.1.130" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.2", "versionEndExcluding": "6.6.80" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.2", "versionEndExcluding": "6.12.17" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.2", "versionEndExcluding": "6.13.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.2", "versionEndExcluding": "6.14" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/d5e86e27de0936f3cb0a299ce519d993e9cf3886" }, { "url": "https://git.kernel.org/stable/c/5a0538ac6826807d6919f6aecbb8996c2865af2c" }, { "url": "https://git.kernel.org/stable/c/f74f6560146714241c6e167b03165ee77a86e316" }, { "url": "https://git.kernel.org/stable/c/904e746b2e7fa952ab8801b303ce826a63153d78" }, { "url": "https://git.kernel.org/stable/c/3ce92ca990cfac88a87c61df3cc0b5880e688ecf" }, { "url": "https://git.kernel.org/stable/c/da9b0ae47f084014b1e4b3f31f70a0defd047ff3" }, { "url": "https://git.kernel.org/stable/c/788dbca056a8783ec063da3c9d49a3a71c76c283" }, { "url": "https://git.kernel.org/stable/c/9593172d93b9f91c362baec4643003dc29802929" } ], "title": "geneve: Fix use-after-free in geneve_find_dev().", 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"2025-03-12T13:23:48.652Z" } }, { "title": "CVE Program Container", "references": [ { "url": "https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html" }, { "url": "https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T19:38:13.635Z" } }, { "x_adpType": "supplier", "providerMetadata": { "orgId": "0b142b55-0307-4c5a-b3c9-f314f3fb7c5e", "shortName": "siemens-SADP", "dateUpdated": "2026-05-12T12:04:06.094Z" }, "affected": [ { "vendor": "Siemens", "product": "SIMATIC S7-1500 TM MFP - GNU/Linux subsystem", "versions": [ { "status": "affected", "version": "0", "lessThan": "*", "versionType": "custom" } ], "defaultStatus": "unknown" } ], "references": [ { "url": "https://cert-portal.siemens.com/productcert/html/ssa-265688.html" } ] } ] } }