{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2025-40064",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2025-04-16T07:20:57.159Z",
        "datePublished": "2025-10-28T11:48:35.155Z",
        "dateUpdated": "2026-09-02T12:49:24.811Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-09-02T12:49:24.811Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmc: Fix use-after-free in __pnet_find_base_ndev().\n\nsyzbot reported use-after-free of net_device in __pnet_find_base_ndev(),\nwhich was called during connect(). [0]\n\nsmc_pnet_find_ism_resource() fetches sk_dst_get(sk)->dev and passes\ndown to pnet_find_base_ndev(), where RTNL is held.  Then, UAF happened\nat __pnet_find_base_ndev() when the dev is first used.\n\nThis means dev had already been freed before acquiring RTNL in\npnet_find_base_ndev().\n\nWhile dev is going away, dst->dev could be swapped with blackhole_netdev,\nand the dev's refcnt by dst will be released.\n\nWe must hold dev's refcnt before calling smc_pnet_find_ism_resource().\n\nAlso, smc_pnet_find_roce_resource() has the same problem.\n\nLet's use __sk_dst_get() and dst_dev_rcu() in the two functions.\n\n[0]:\nBUG: KASAN: use-after-free in __pnet_find_base_ndev+0x1b1/0x1c0 net/smc/smc_pnet.c:926\nRead of size 1 at addr ffff888036bac33a by task syz.0.3632/18609\n\nCPU: 1 UID: 0 PID: 18609 Comm: syz.0.3632 Not tainted syzkaller #0 PREEMPT(full)\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025\nCall Trace:\n <TASK>\n dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120\n print_address_description mm/kasan/report.c:378 [inline]\n print_report+0xca/0x240 mm/kasan/report.c:482\n kasan_report+0x118/0x150 mm/kasan/report.c:595\n __pnet_find_base_ndev+0x1b1/0x1c0 net/smc/smc_pnet.c:926\n pnet_find_base_ndev net/smc/smc_pnet.c:946 [inline]\n smc_pnet_find_ism_by_pnetid net/smc/smc_pnet.c:1103 [inline]\n smc_pnet_find_ism_resource+0xef/0x390 net/smc/smc_pnet.c:1154\n smc_find_ism_device net/smc/af_smc.c:1030 [inline]\n smc_find_proposal_devices net/smc/af_smc.c:1115 [inline]\n __smc_connect+0x372/0x1890 net/smc/af_smc.c:1545\n smc_connect+0x877/0xd90 net/smc/af_smc.c:1715\n __sys_connect_file net/socket.c:2086 [inline]\n __sys_connect+0x313/0x440 net/socket.c:2105\n __do_sys_connect net/socket.c:2111 [inline]\n __se_sys_connect net/socket.c:2108 [inline]\n __x64_sys_connect+0x7a/0x90 net/socket.c:2108\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\nRIP: 0033:0x7f47cbf8eba9\nCode: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48\nRSP: 002b:00007f47ccdb1038 EFLAGS: 00000246 ORIG_RAX: 000000000000002a\nRAX: ffffffffffffffda RBX: 00007f47cc1d5fa0 RCX: 00007f47cbf8eba9\nRDX: 0000000000000010 RSI: 0000200000000280 RDI: 000000000000000b\nRBP: 00007f47cc011e19 R08: 0000000000000000 R09: 0000000000000000\nR10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000\nR13: 00007f47cc1d6038 R14: 00007f47cc1d5fa0 R15: 00007ffc512f8aa8\n </TASK>\n\nThe buggy address belongs to the physical page:\npage: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888036bacd00 pfn:0x36bac\nflags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)\nraw: 00fff00000000000 ffffea0001243d08 ffff8880b863fdc0 0000000000000000\nraw: ffff888036bacd00 0000000000000000 00000000ffffffff 0000000000000000\npage dumped because: kasan: bad access detected\npage_owner tracks the page as freed\npage last allocated via order 2, migratetype Unmovable, gfp_mask 0x446dc0(GFP_KERNEL_ACCOUNT|__GFP_ZERO|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_COMP), pid 16741, tgid 16741 (syz-executor), ts 343313197788, free_ts 380670750466\n set_page_owner include/linux/page_owner.h:32 [inline]\n post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851\n prep_new_page mm/page_alloc.c:1859 [inline]\n get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3858\n __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148\n alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416\n ___kmalloc_large_node+0x5f/0x1b0 mm/slub.c:4317\n __kmalloc_large_node_noprof+0x18/0x90 mm/slub.c:4348\n __do_kmalloc_node mm/slub.c:4364 [inline]\n __kvmalloc_node\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 triggered through the connect() syscall on a locally created AF_SMC socket, combined with locally driven netdev teardown (rtnl_dellink) to free the device. Although the same helpers are also reached from the server-side listen path, the freeing side of the race is not remotely controllable, so local access is the realistic delivery vector.\nAC:L - The attacker controls both sides of the race: they create the netdev and route in their own network namespace, initiate the SMC connect that caches the dst, and delete the device concurrently; the reader blocks on rtnl_lock held by the deleting task and dereferences the device immediately after netdev_run_todo() frees it, making the window wide and the trigger reliably repeatable in a loop.\nPR:L - No capability check exists on AF_SMC socket creation and the module autoloads via net-pf-43 for unprivileged users; the netdev create/delete side needs only CAP_NET_ADMIN inside a user+network namespace obtainable with unshare -Urn by any unprivileged local user.\nUI:N - The attacker performs every step — socket creation, local SMC listener, connect, and device deletion — with no action required from any other user or administrator.\nS:U - The use-after-free corrupts kernel memory within the same kernel security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - The freed net_device is read and its adj_list is walked, yielding an attacker-influenceable pointer that is further dereferenced (dev.parent, dev_port, dev_net()->net_generic()); with a page-level heap spray of the freed kvmalloc allocation this provides an arbitrary-read oriented primitive over kernel memory.\nI:H - Controlling the freed net_device contents lets the attacker steer base_ndev to a crafted address that is then used for mutex_lock(&pnettable->lock) and list traversal, giving a controlled write/corruption primitive suitable for privilege escalation.\nA:H - The use-after-free reliably produces a KASAN-detected invalid access and, on production kernels, wild-pointer dereferences leading to kernel oops or panic, and it can be re-triggered at will."
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/smc/smc_pnet.c"
                    ],
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                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "net/smc/smc_pnet.c"
                    ],
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                            "version": "4.19",
                            "status": "affected"
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                        {
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                            "status": "unaffected",
                            "versionType": "semver"
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                            "version": "6.1.187",
                            "lessThanOrEqual": "6.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
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                        {
                            "version": "6.6.156",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.108",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.17.3",
                            "lessThanOrEqual": "6.17.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }
            ],
            "cpeApplicability": [
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                    "nodes": [
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                            "operator": "OR",
                            "negate": false,
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            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/005a7173d8e4710646043a681af36f79ce05a29b"
                },
                {
                    "url": "https://git.kernel.org/stable/c/302dbed4760bcd19a661cc1c282d91bb7481307e"
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                {
                    "url": "https://git.kernel.org/stable/c/3d3466878afd8d43ec0ca2facfbc7f03e40d0f79"
                }
            ],
            "title": "smc: Fix use-after-free in __pnet_find_base_ndev().",
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        "adp": [
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                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-06-16T19:39:09.971835Z",
                                "id": "CVE-2025-40064",
                                "options": [
                                    {
                                        "Exploitation": "none"
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}