{"id":"CVE-2021-47266","state":"PUBLISHED","title":"RDMA/ipoib: Fix warning caused by destroying non-initial netns","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 <0f> 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.","publishedAt":"2024-05-21T14:19:57.249Z","updatedAt":"2026-05-23T15:19:37.056Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"dc1d4c658b9c123e31054fffcbc0b23566694b1a","status":"affected","lessThan":"64f1fb6acc2ab95982fc4334f351d7576c26f313","versionType":"git"},{"version":"5ce2dced8e95e76ff7439863a118a053a7fc6f91","status":"affected","lessThan":"67cf4e447b5e5e9e94996cb6812ae2828e0e0e27","versionType":"git"},{"version":"5ce2dced8e95e76ff7439863a118a053a7fc6f91","status":"affected","lessThan":"0a672f7d89db2da17ae02733ccc08458be72a6f8","versionType":"git"},{"version":"5ce2dced8e95e76ff7439863a118a053a7fc6f91","status":"affected","lessThan":"a3e74fb9247cd530dca246699d5eb5a691884d32","versionType":"git"},{"version":"938e97b946ecf5aa3ccc04ff4ad116e92d894270","status":"affected","versionType":"git"},{"version":"86e76dbea6379bb272bceb36fe4217f34ff6858d","status":"affected","versionType":"git"},{"version":"5.4.73","status":"affected","lessThan":"5.4.126","versionType":"semver"},{"version":"5.8.17","status":"affected","lessThan":"5.9","versionType":"semver"},{"version":"5.9.2","status":"affected","lessThan":"5.10","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/infiniband/ulp/ipoib/ipoib_netlink.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.10","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.10","versionType":"semver"},{"version":"5.4.126","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.44","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.12.11","status":"unaffected","lessThanOrEqual":"5.12.*","versionType":"semver"},{"version":"5.13","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/infiniband/ulp/ipoib/ipoib_netlink.c"]}],"references":["https://git.kernel.org/stable/c/64f1fb6acc2ab95982fc4334f351d7576c26f313","https://git.kernel.org/stable/c/67cf4e447b5e5e9e94996cb6812ae2828e0e0e27","https://git.kernel.org/stable/c/0a672f7d89db2da17ae02733ccc08458be72a6f8","https://git.kernel.org/stable/c/a3e74fb9247cd530dca246699d5eb5a691884d32"],"weaknesses":[],"ingestedAt":"2026-10-29T19:49:19.404Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2021/47xxx/CVE-2021-47266.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2021-47266","state":"PUBLISHED","datePublished":"2024-05-21T14:19:57.249Z","dateUpdated":"2026-05-23T15:19:37.056Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-05-21T13:27:52.126Z"},"containers":{"cna":{"title":"RDMA/ipoib: Fix warning caused by destroying non-initial netns","descriptions":[{"lang":"en","value":"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 <0f> 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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"dc1d4c658b9c123e31054fffcbc0b23566694b1a","status":"affected","lessThan":"64f1fb6acc2ab95982fc4334f351d7576c26f313","versionType":"git"},{"version":"5ce2dced8e95e76ff7439863a118a053a7fc6f91","status":"affected","lessThan":"67cf4e447b5e5e9e94996cb6812ae2828e0e0e27","versionType":"git"},{"version":"5ce2dced8e95e76ff7439863a118a053a7fc6f91","status":"affected","lessThan":"0a672f7d89db2da17ae02733ccc08458be72a6f8","versionType":"git"},{"version":"5ce2dced8e95e76ff7439863a118a053a7fc6f91","status":"affected","lessThan":"a3e74fb9247cd530dca246699d5eb5a691884d32","versionType":"git"},{"version":"938e97b946ecf5aa3ccc04ff4ad116e92d894270","status":"affected","versionType":"git"},{"version":"86e76dbea6379bb272bceb36fe4217f34ff6858d","status":"affected","versionType":"git"},{"version":"5.4.73","status":"affected","lessThan":"5.4.126","versionType":"semver"},{"version":"5.8.17","status":"affected","lessThan":"5.9","versionType":"semver"},{"version":"5.9.2","status":"affected","lessThan":"5.10","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/infiniband/ulp/ipoib/ipoib_netlink.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.10","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.10","versionType":"semver"},{"version":"5.4.126","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.44","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.12.11","status":"unaffected","lessThanOrEqual":"5.12.*","versionType":"semver"},{"version":"5.13","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/infiniband/ulp/ipoib/ipoib_netlink.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/64f1fb6acc2ab95982fc4334f351d7576c26f313"},{"url":"https://git.kernel.org/stable/c/67cf4e447b5e5e9e94996cb6812ae2828e0e0e27"},{"url":"https://git.kernel.org/stable/c/0a672f7d89db2da17ae02733ccc08458be72a6f8"},{"url":"https://git.kernel.org/stable/c/a3e74fb9247cd530dca246699d5eb5a691884d32"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-23T15:19:37.056Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.4.73","versionEndExcluding":"5.4.126"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"5.10.44"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"5.12.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"5.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.8.17"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.9.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2024-06-12T15:25:18.906799Z","id":"CVE-2021-47266","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2024-06-12T15:25:33.969Z"}},{"title":"CVE Program Container","references":[{"url":"https://git.kernel.org/stable/c/64f1fb6acc2ab95982fc4334f351d7576c26f313","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/67cf4e447b5e5e9e94996cb6812ae2828e0e0e27","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/0a672f7d89db2da17ae02733ccc08458be72a6f8","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/a3e74fb9247cd530dca246699d5eb5a691884d32","tags":["x_transferred"]}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2024-08-04T05:32:08.117Z"}}]}}}