{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-47237 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2021-47237 is a medium-severity denial of service vulnerability in Linux kernel, published on 21 May 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-2021-47237 and fix it if it is affected.\n\nWhat it is: CVE-2021-47237 is a medium-severity denial of service vulnerability in Linux kernel, published on 21 May 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-2021-47237 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-2021-47237/ (Markdown: https://insights.sbomify.com/CVE-2021-47237/index.md)","id":"CVE-2021-47237","markdown":"https://insights.sbomify.com/CVE-2021-47237/index.md","name":"CVE-2021-47237","record":{"aliases":["DEBIAN-CVE-2021-47237","GHSA-7r2w-9mrv-hfqg","UBUNTU-CVE-2021-47237"],"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 memory leak in the Linux kernel's hamradio driver allows local attackers to exhaust system memory, causing a denial of service.","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":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-401","name":"Missing Release of Memory after Effective Lifetime"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: hamradio: fix memory leak in mkiss_close\n\nMy local syzbot instance hit memory leak in\nmkiss_open()[1]. The problem was in missing\nfree_netdev() in mkiss_close().\n\nIn mkiss_open() netdevice is allocated and then\nregistered, but in mkiss_close() netdevice was\nonly unregistered, but not freed.\n\nFail log:\n\nBUG: memory leak\nunreferenced object 0xffff8880281ba000 (size 4096):\n  comm \"syz-executor.1\", pid 11443, jiffies 4295046091 (age 17.660s)\n  hex dump (first 32 bytes):\n    61 78 30 00 00 00 00 00 00 00 00 00 00 00 00 00  ax0.............\n    00 27 fa 2a 80 88 ff ff 00 00 00 00 00 00 00 00  .'.*............\n  backtrace:\n    [\u003cffffffff81a27201\u003e] kvmalloc_node+0x61/0xf0\n    [\u003cffffffff8706e7e8\u003e] alloc_netdev_mqs+0x98/0xe80\n    [\u003cffffffff84e64192\u003e] mkiss_open+0xb2/0x6f0 [1]\n    [\u003cffffffff842355db\u003e] tty_ldisc_open+0x9b/0x110\n    [\u003cffffffff84236488\u003e] tty_set_ldisc+0x2e8/0x670\n    [\u003cffffffff8421f7f3\u003e] tty_ioctl+0xda3/0x1440\n    [\u003cffffffff81c9f273\u003e] __x64_sys_ioctl+0x193/0x200\n    [\u003cffffffff8911263a\u003e] do_syscall_64+0x3a/0xb0\n    [\u003cffffffff89200068\u003e] entry_SYSCALL_64_after_hwframe+0x44/0xae\n\nBUG: memory leak\nunreferenced object 0xffff8880141a9a00 (size 96):\n  comm \"syz-executor.1\", pid 11443, jiffies 4295046091 (age 17.660s)\n  hex dump (first 32 bytes):\n    e8 a2 1b 28 80 88 ff ff e8 a2 1b 28 80 88 ff ff  ...(.......(....\n    98 92 9c aa b0 40 02 00 00 00 00 00 00 00 00 00  .....@..........\n  backtrace:\n    [\u003cffffffff8709f68b\u003e] __hw_addr_create_ex+0x5b/0x310\n    [\u003cffffffff8709fb38\u003e] __hw_addr_add_ex+0x1f8/0x2b0\n    [\u003cffffffff870a0c7b\u003e] dev_addr_init+0x10b/0x1f0\n    [\u003cffffffff8706e88b\u003e] alloc_netdev_mqs+0x13b/0xe80\n    [\u003cffffffff84e64192\u003e] mkiss_open+0xb2/0x6f0 [1]\n    [\u003cffffffff842355db\u003e] tty_ldisc_open+0x9b/0x110\n    [\u003cffffffff84236488\u003e] tty_set_ldisc+0x2e8/0x670\n    [\u003cffffffff8421f7f3\u003e] tty_ioctl+0xda3/0x1440\n    [\u003cffffffff81c9f273\u003e] __x64_sys_ioctl+0x193/0x200\n    [\u003cffffffff8911263a\u003e] do_syscall_64+0x3a/0xb0\n    [\u003cffffffff89200068\u003e] entry_SYSCALL_64_after_hwframe+0x44/0xae\n\nBUG: memory leak\nunreferenced object 0xffff8880219bfc00 (size 512):\n  comm \"syz-executor.1\", pid 11443, jiffies 4295046091 (age 17.660s)\n  hex dump (first 32 bytes):\n    00 a0 1b 28 80 88 ff ff 80 8f b1 8d ff ff ff ff  ...(............\n    80 8f b1 8d ff ff ff ff 00 00 00 00 00 00 00 00  ................\n  backtrace:\n    [\u003cffffffff81a27201\u003e] kvmalloc_node+0x61/0xf0\n    [\u003cffffffff8706eec7\u003e] alloc_netdev_mqs+0x777/0xe80\n    [\u003cffffffff84e64192\u003e] mkiss_open+0xb2/0x6f0 [1]\n    [\u003cffffffff842355db\u003e] tty_ldisc_open+0x9b/0x110\n    [\u003cffffffff84236488\u003e] tty_set_ldisc+0x2e8/0x670\n    [\u003cffffffff8421f7f3\u003e] tty_ioctl+0xda3/0x1440\n    [\u003cffffffff81c9f273\u003e] __x64_sys_ioctl+0x193/0x200\n    [\u003cffffffff8911263a\u003e] do_syscall_64+0x3a/0xb0\n    [\u003cffffffff89200068\u003e] entry_SYSCALL_64_after_hwframe+0x44/0xae\n\nBUG: memory leak\nunreferenced object 0xffff888029b2b200 (size 256):\n  comm \"syz-executor.1\", pid 11443, jiffies 4295046091 (age 17.660s)\n  hex dump (first 32 bytes):\n    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................\n    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................\n  backtrace:\n    [\u003cffffffff81a27201\u003e] kvmalloc_node+0x61/0xf0\n    [\u003cffffffff8706f062\u003e] alloc_netdev_mqs+0x912/0xe80\n    [\u003cffffffff84e64192\u003e] mkiss_open+0xb2/0x6f0 [1]\n    [\u003cffffffff842355db\u003e] tty_ldisc_open+0x9b/0x110\n    [\u003cffffffff84236488\u003e] tty_set_ldisc+0x2e8/0x670\n    [\u003cffffffff8421f7f3\u003e] tty_ioctl+0xda3/0x1440\n    [\u003cffffffff81c9f273\u003e] __x64_sys_ioctl+0x193/0x200\n    [\u003cffffffff8911263a\u003e] do_syscall_64+0x3a/0xb0\n    [\u003cffffffff89200068\u003e] entry_SYSCALL_64_after_hwframe+0x44/0xae","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":"net: hamradio: fix memory leak in mkiss_close","id":"CVE-2021-47237","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":8,"next":{"headline":"net: ipv4: fix memory leak in ip_mc_add1_src","id":"CVE-2021-47238"},"packages":[],"prev":{"headline":"net: cdc_eem: fix tx fixup skb leak","id":"CVE-2021-47236"},"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":"partial"},"state":"PUBLISHED","updated":"2026-05-11","vendors":["Linux"]},"summary":"A memory leak in the Linux kernel's hamradio driver allows local attackers to exhaust system memory, causing a denial of service.","url":"https://insights.sbomify.com/CVE-2021-47237/"}