{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-47242 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2021-47242 yet. Limit exposure of the affected software until one is available.","what":"CVE-2021-47242 is a high-severity denial of service vulnerability in Linux kernel, published on 21 May 2024. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2021-47242 and fix it if it is affected.\n\nWhat it is: CVE-2021-47242 is a high-severity denial of service vulnerability in Linux kernel, published on 21 May 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2021-47242 in the wild and no public exploit code.\n\nAffected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2021-47242/ (Markdown: https://insights.sbomify.com/CVE-2021-47242/index.md)","id":"CVE-2021-47242","markdown":"https://insights.sbomify.com/CVE-2021-47242/index.md","name":"CVE-2021-47242","record":{"aliases":["GHSA-gc8r-vh42-27g4","UBUNTU-CVE-2021-47242"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Linux kernel","requires_auth":"none","summary":"A soft lockup in the Linux kernel's MPTCP subflow error reporting can cause a denial of service by hanging the CPU.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":7.5,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-667","name":"Improper Locking"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: fix soft lookup in subflow_error_report()\n\nMaxim reported a soft lookup in subflow_error_report():\n\n watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [swapper/0:0]\n RIP: 0010:native_queued_spin_lock_slowpath\n RSP: 0018:ffffa859c0003bc0 EFLAGS: 00000202\n RAX: 0000000000000101 RBX: 0000000000000001 RCX: 0000000000000000\n RDX: ffff9195c2772d88 RSI: 0000000000000000 RDI: ffff9195c2772d88\n RBP: ffff9195c2772d00 R08: 00000000000067b0 R09: c6e31da9eb1e44f4\n R10: ffff9195ef379700 R11: ffff9195edb50710 R12: ffff9195c2772d88\n R13: ffff9195f500e3d0 R14: ffff9195ef379700 R15: ffff9195ef379700\n FS:  0000000000000000(0000) GS:ffff91961f400000(0000) knlGS:0000000000000000\n CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 000000c000407000 CR3: 0000000002988000 CR4: 00000000000006f0\n Call Trace:\n  \u003cIRQ\u003e\n _raw_spin_lock_bh\n subflow_error_report\n mptcp_subflow_data_available\n __mptcp_move_skbs_from_subflow\n mptcp_data_ready\n tcp_data_queue\n tcp_rcv_established\n tcp_v4_do_rcv\n tcp_v4_rcv\n ip_protocol_deliver_rcu\n ip_local_deliver_finish\n __netif_receive_skb_one_core\n netif_receive_skb\n rtl8139_poll 8139too\n __napi_poll\n net_rx_action\n __do_softirq\n __irq_exit_rcu\n common_interrupt\n  \u003c/IRQ\u003e\n\nThe calling function - mptcp_subflow_data_available() - can be invoked\nfrom different contexts:\n- plain ssk socket lock\n- ssk socket lock + mptcp_data_lock\n- ssk socket lock + mptcp_data_lock + msk socket lock.\n\nSince subflow_error_report() tries to acquire the mptcp_data_lock, the\nlatter two call chains will cause soft lookup.\n\nThis change addresses the issue moving the error reporting call to\nouter functions, where the held locks list is known and the we can\nacquire only the needed one.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":false,"headline":"mptcp: fix soft lookup in subflow_error_report()","id":"CVE-2021-47242","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"denial_of_service","year":"2021"},"n_packages":0,"n_references":2,"next":{"headline":"sch_cake: Fix out of bounds when parsing TCP options and header","id":"CVE-2021-47243"},"packages":[],"prev":{"headline":"ethtool: strset: fix message length calculation","id":"CVE-2021-47241"},"products":["Linux"],"published":"2024-05-21","related":[{"cvss_score":8.8,"headline":"Linux Kernel Out-of-Bounds Write","id":"CVE-2026-53266","kev_date_added":"2026-09-18","published":"2026-06-25"},{"cvss_score":8.8,"headline":"Linux Kernel Improper Input Validation","id":"CVE-2013-6282","kev_date_added":"2022-09-15","published":"2013-11-19"},{"cvss_score":8.4,"headline":"Linux Kernel Heap-Based Buffer Overflow","id":"CVE-2022-0185","kev_date_added":"2024-08-21","published":"2022-02-11"},{"cvss_score":8.4,"headline":"Linux Kernel Privilege Escalation","id":"CVE-2013-2094","kev_date_added":"2022-09-15","published":"2013-05-14"},{"cvss_score":7.8,"headline":"Linux Kernel Unspecified","id":"CVE-2026-53362","kev_date_added":"2026-08-27","published":"2026-07-04"},{"cvss_score":7.8,"headline":"Linux Kernel Missing Initialization of a Variable","id":"CVE-2026-46300","kev_date_added":"2026-10-28","published":"2026-05-23"},{"cvss_score":7.8,"headline":"Linux Kernel Race Condition","id":"CVE-2025-39964","kev_date_added":"2026-09-18","published":"2025-10-13"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-08-05","vendors":["Linux"]},"summary":"A soft lockup in the Linux kernel's MPTCP subflow error reporting can cause a denial of service by hanging the CPU.","url":"https://insights.sbomify.com/CVE-2021-47242/"}