{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-47266 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2021-47266 is a medium-severity 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-2021-47266 and fix it if it is affected.\n\nWhat it is: CVE-2021-47266 is a medium-severity 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-2021-47266 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-2021-47266/ (Markdown: https://insights.sbomify.com/CVE-2021-47266/index.md)","id":"CVE-2021-47266","markdown":"https://insights.sbomify.com/CVE-2021-47266/index.md","name":"CVE-2021-47266","record":{"aliases":["DEBIAN-CVE-2021-47266","GHSA-8cxw-6695-4jq3","UBUNTU-CVE-2021-47266"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel RDMA","requires_auth":"low_privilege","summary":"A null pointer dereference in the Linux kernel RDMA/ipoib module causes a system crash when destroying a non-initial network namespace.","user_interaction":"not_required","vuln_class":"null_dereference"},"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-476","name":"NULL Pointer Dereference"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/ipoib: Fix warning caused by destroying non-initial netns\n\nAfter the commit 5ce2dced8e95 (\"RDMA/ipoib: Set rtnl_link_ops for ipoib\ninterfaces\"), if the IPoIB device is moved to non-initial netns,\ndestroying that netns lets the device vanish instead of moving it back to\nthe initial netns, This is happening because default_device_exit() skips\nthe interfaces due to having rtnl_link_ops set.\n\nSteps to reporoduce:\n  ip netns add foo\n  ip link set mlx5_ib0 netns foo\n  ip netns delete foo\n\nWARNING: CPU: 1 PID: 704 at net/core/dev.c:11435 netdev_exit+0x3f/0x50\nModules linked in: xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT\nnf_reject_ipv4 nft_compat nft_counter nft_chain_nat nf_nat nf_conntrack\nnf_defrag_ipv6 nf_defrag_ipv4 nf_tables nfnetlink tun d\n fuse\nCPU: 1 PID: 704 Comm: kworker/u64:3 Tainted: G S      W  5.13.0-rc1+ #1\nHardware name: Dell Inc. PowerEdge R630/02C2CP, BIOS 2.1.5 04/11/2016\nWorkqueue: netns cleanup_net\nRIP: 0010:netdev_exit+0x3f/0x50\nCode: 48 8b bb 30 01 00 00 e8 ef 81 b1 ff 48 81 fb c0 3a 54 a1 74 13 48\n8b 83 90 00 00 00 48 81 c3 90 00 00 00 48 39 d8 75 02 5b c3 \u003c0f\u003e 0b 5b\nc3 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 0f 1f 44 00\nRSP: 0018:ffffb297079d7e08 EFLAGS: 00010206\nRAX: ffff8eb542c00040 RBX: ffff8eb541333150 RCX: 000000008010000d\nRDX: 000000008010000e RSI: 000000008010000d RDI: ffff8eb440042c00\nRBP: ffffb297079d7e48 R08: 0000000000000001 R09: ffffffff9fdeac00\nR10: ffff8eb5003be000 R11: 0000000000000001 R12: ffffffffa1545620\nR13: ffffffffa1545628 R14: 0000000000000000 R15: ffffffffa1543b20\nFS:  0000000000000000(0000) GS:ffff8ed37fa00000(0000) knlGS:0000000000000000\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 00005601b5f4c2e8 CR3: 0000001fc8c10002 CR4: 00000000003706e0\nDR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\nDR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\nCall Trace:\n ops_exit_list.isra.9+0x36/0x70\n cleanup_net+0x234/0x390\n process_one_work+0x1cb/0x360\n ? process_one_work+0x360/0x360\n worker_thread+0x30/0x370\n ? process_one_work+0x360/0x360\n kthread+0x116/0x130\n ? kthread_park+0x80/0x80\n ret_from_fork+0x22/0x30\n\nTo avoid the above warning and later on the kernel panic that could happen\non shutdown due to a NULL pointer dereference, make sure to set the\nnetns_refund flag that was introduced by commit 3a5ca857079e (\"can: dev:\nMove device back to init netns on owning netns delete\") to properly\nrestore the IPoIB interfaces to the initial netns.","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":"RDMA/ipoib: Fix warning caused by destroying non-initial netns","id":"CVE-2021-47266","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"null_dereference","year":"2021"},"n_packages":0,"n_references":4,"next":{"headline":"usb: fix various gadget panics on 10gbps cabling","id":"CVE-2021-47267"},"packages":[],"prev":{"headline":"RDMA: Verify port when creating flow rule","id":"CVE-2021-47265"},"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":"2026-05-23","vendors":["Linux"]},"summary":"A null pointer dereference in the Linux kernel RDMA/ipoib module causes a system crash when destroying a non-initial network namespace.","url":"https://insights.sbomify.com/CVE-2021-47266/"}