{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-47590 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2021-47590 is a medium-severity vulnerability in Linux kernel, published on 19 Jun 2024. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2021-47590 and fix it if it is affected.\n\nWhat it is: CVE-2021-47590 is a medium-severity vulnerability in Linux kernel, published on 19 Jun 2024. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2021-47590 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-2021-47590/ (Markdown: https://insights.sbomify.com/CVE-2021-47590/index.md)","id":"CVE-2021-47590","markdown":"https://insights.sbomify.com/CVE-2021-47590/index.md","name":"CVE-2021-47590","record":{"aliases":["DEBIAN-CVE-2021-47590","GHSA-phj6-5vrc-g27m","UBUNTU-CVE-2021-47590"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A deadlock in the Linux kernel MPTCP subsystem allows local attackers to cause a denial of service by triggering a specific socket lock contention scenario.","user_interaction":"not_required","vuln_class":"race_condition"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":5.5,"severity":"medium","source":"nvd","vector":"CVSS:3.1/AV:L/AC:L/PR:L/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 deadlock in __mptcp_push_pending()\n\n__mptcp_push_pending() may call mptcp_flush_join_list() with subflow\nsocket lock held. If such call hits mptcp_sockopt_sync_all() then\nsubsequently __mptcp_sockopt_sync() could try to lock the subflow\nsocket for itself, causing a deadlock.\n\nsysrq: Show Blocked State\ntask:ss-server       state:D stack:    0 pid:  938 ppid:     1 flags:0x00000000\nCall Trace:\n \u003cTASK\u003e\n __schedule+0x2d6/0x10c0\n ? __mod_memcg_state+0x4d/0x70\n ? csum_partial+0xd/0x20\n ? _raw_spin_lock_irqsave+0x26/0x50\n schedule+0x4e/0xc0\n __lock_sock+0x69/0x90\n ? do_wait_intr_irq+0xa0/0xa0\n __lock_sock_fast+0x35/0x50\n mptcp_sockopt_sync_all+0x38/0xc0\n __mptcp_push_pending+0x105/0x200\n mptcp_sendmsg+0x466/0x490\n sock_sendmsg+0x57/0x60\n __sys_sendto+0xf0/0x160\n ? do_wait_intr_irq+0xa0/0xa0\n ? fpregs_restore_userregs+0x12/0xd0\n __x64_sys_sendto+0x20/0x30\n do_syscall_64+0x38/0x90\n entry_SYSCALL_64_after_hwframe+0x44/0xae\nRIP: 0033:0x7f9ba546c2d0\nRSP: 002b:00007ffdc3b762d8 EFLAGS: 00000246 ORIG_RAX: 000000000000002c\nRAX: ffffffffffffffda RBX: 00007f9ba56c8060 RCX: 00007f9ba546c2d0\nRDX: 000000000000077a RSI: 0000000000e5e180 RDI: 0000000000000234\nRBP: 0000000000cc57f0 R08: 0000000000000000 R09: 0000000000000000\nR10: 0000000000000000 R11: 0000000000000246 R12: 00007f9ba56c8060\nR13: 0000000000b6ba60 R14: 0000000000cc7840 R15: 41d8685b1d7901b8\n \u003c/TASK\u003e\n\nFix the issue by using __mptcp_flush_join_list() instead of plain\nmptcp_flush_join_list() inside __mptcp_push_pending(), as suggested by\nFlorian. The sockopt sync will be deferred to the workqueue.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"mptcp: fix deadlock in __mptcp_push_pending()","id":"CVE-2021-47590","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"race_condition","year":"2021"},"n_packages":0,"n_references":2,"next":{"headline":"mptcp: remove tcp ulp setsockopt support","id":"CVE-2021-47591"},"packages":[],"prev":{"headline":"igbvf: fix double free in `igbvf_probe`","id":"CVE-2021-47589"},"products":["Linux"],"published":"2024-06-19","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":"partial"},"state":"PUBLISHED","updated":"2026-05-11","vendors":["Linux"]},"summary":"A deadlock in the Linux kernel MPTCP subsystem allows local attackers to cause a denial of service by triggering a specific socket lock contention scenario.","url":"https://insights.sbomify.com/CVE-2021-47590/"}