{
    "data_version": "4.0",
    "data_type": "CVE",
    "data_format": "MITRE",
    "CVE_data_meta": {
        "ID": "CVE-2024-43887",
        "ASSIGNER": "cve@kernel.org",
        "STATE": "PUBLIC"
    },
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/tcp: Disable TCP-AO static key after RCU grace period\n\nThe lifetime of TCP-AO static_key is the same as the last\ntcp_ao_info. On the socket destruction tcp_ao_info ceases to be\nwith RCU grace period, while tcp-ao static branch is currently deferred\ndestructed. The static key definition is\n: DEFINE_STATIC_KEY_DEFERRED_FALSE(tcp_ao_needed, HZ);\n\nwhich means that if RCU grace period is delayed by more than a second\nand tcp_ao_needed is in the process of disablement, other CPUs may\nyet see tcp_ao_info which atent dead, but soon-to-be.\nAnd that breaks the assumption of static_key_fast_inc_not_disabled().\n\nSee the comment near the definition:\n> * The caller must make sure that the static key can't get disabled while\n> * in this function. It doesn't patch jump labels, only adds a user to\n> * an already enabled static key.\n\nOriginally it was introduced in commit eb8c507296f6 (\"jump_label:\nPrevent key->enabled int overflow\"), which is needed for the atomic\ncontexts, one of which would be the creation of a full socket from a\nrequest socket. In that atomic context, it's known by the presence\nof the key (md5/ao) that the static branch is already enabled.\nSo, the ref counter for that static branch is just incremented\ninstead of holding the proper mutex.\nstatic_key_fast_inc_not_disabled() is just a helper for such usage\ncase. But it must not be used if the static branch could get disabled\nin parallel as it's not protected by jump_label_mutex and as a result,\nraces with jump_label_update() implementation details.\n\nHappened on netdev test-bot[1], so not a theoretical issue:\n\n[] jump_label: Fatal kernel bug, unexpected op at tcp_inbound_hash+0x1a7/0x870 [ffffffffa8c4e9b7] (eb 50 0f 1f 44 != 66 90 0f 1f 00)) size:2 type:1\n[] ------------[ cut here ]------------\n[] kernel BUG at arch/x86/kernel/jump_label.c:73!\n[] Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI\n[] CPU: 3 PID: 243 Comm: kworker/3:3 Not tainted 6.10.0-virtme #1\n[] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014\n[] Workqueue: events jump_label_update_timeout\n[] RIP: 0010:__jump_label_patch+0x2f6/0x350\n...\n[] Call Trace:\n[]  <TASK>\n[]  arch_jump_label_transform_queue+0x6c/0x110\n[]  __jump_label_update+0xef/0x350\n[]  __static_key_slow_dec_cpuslocked.part.0+0x3c/0x60\n[]  jump_label_update_timeout+0x2c/0x40\n[]  process_one_work+0xe3b/0x1670\n[]  worker_thread+0x587/0xce0\n[]  kthread+0x28a/0x350\n[]  ret_from_fork+0x31/0x70\n[]  ret_from_fork_asm+0x1a/0x30\n[]  </TASK>\n[] Modules linked in: veth\n[] ---[ end trace 0000000000000000 ]---\n[] RIP: 0010:__jump_label_patch+0x2f6/0x350\n\n[1]: https://netdev-3.bots.linux.dev/vmksft-tcp-ao-dbg/results/696681/5-connect-deny-ipv6/stderr"
            }
        ]
    },
    "problemtype": {
        "problemtype_data": [
            {
                "description": [
                    {
                        "lang": "eng",
                        "value": "n/a"
                    }
                ]
            }
        ]
    },
    "affects": {
        "vendor": {
            "vendor_data": [
                {
                    "vendor_name": "Linux",
                    "product": {
                        "product_data": [
                            {
                                "product_name": "Linux",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "<",
                                            "version_name": "67fa83f7c86a",
                                            "version_value": "954d55a59b25"
                                        },
                                        {
                                            "version_value": "not down converted",
                                            "x_cve_json_5_version_data": {
                                                "versions": [
                                                    {
                                                        "version": "6.7",
                                                        "status": "affected"
                                                    },
                                                    {
                                                        "version": "0",
                                                        "lessThan": "6.7",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.10.5",
                                                        "lessThanOrEqual": "6.10.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.11",
                                                        "lessThanOrEqual": "*",
                                                        "status": "unaffected",
                                                        "versionType": "original_commit_for_fix"
                                                    }
                                                ],
                                                "defaultStatus": "affected"
                                            }
                                        }
                                    ]
                                }
                            }
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    "references": {
        "reference_data": [
            {
                "url": "https://git.kernel.org/stable/c/954d55a59b2501f4a9bd693b40ce45a1c46cb2b3",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/954d55a59b2501f4a9bd693b40ce45a1c46cb2b3"
            },
            {
                "url": "https://git.kernel.org/stable/c/14ab4792ee120c022f276a7e4768f4dcb08f0cdd",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/14ab4792ee120c022f276a7e4768f4dcb08f0cdd"
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