{"id":"CVE-2021-47201","state":"PUBLISHED","title":"iavf: free q_vectors before queues in iavf_disable_vf","description":"In the Linux kernel, the following vulnerability has been resolved:\n\niavf: free q_vectors before queues in iavf_disable_vf\n\niavf_free_queues() clears adapter->num_active_queues, which\niavf_free_q_vectors() relies on, so swap the order of these two function\ncalls in iavf_disable_vf(). This resolves a panic encountered when the\ninterface is disabled and then later brought up again after PF\ncommunication is restored.","publishedAt":"2024-04-10T18:56:35.774Z","updatedAt":"2026-08-05T08:46:42.381Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"65c7006f234c9ede887d468f595f259a5c5cc552","status":"affected","lessThan":"926e8c83d4c1c2dac0026637eb0d492df876489e","versionType":"git"},{"version":"65c7006f234c9ede887d468f595f259a5c5cc552","status":"affected","lessThan":"78638b47132244e3934dc5dc79f6372d5ce8e98c","versionType":"git"},{"version":"65c7006f234c9ede887d468f595f259a5c5cc552","status":"affected","lessThan":"9ef6589cac9a8c47f5544ccdf4c498093733bb3f","versionType":"git"},{"version":"65c7006f234c9ede887d468f595f259a5c5cc552","status":"affected","lessThan":"89f22f129696ab53cfbc608e0a2184d0fea46ac1","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/intel/iavf/iavf_main.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.13","versionType":"semver"},{"version":"5.4.162","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.82","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.5","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"5.16","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/intel/iavf/iavf_main.c"]}],"references":["https://git.kernel.org/stable/c/926e8c83d4c1c2dac0026637eb0d492df876489e","https://git.kernel.org/stable/c/78638b47132244e3934dc5dc79f6372d5ce8e98c","https://git.kernel.org/stable/c/9ef6589cac9a8c47f5544ccdf4c498093733bb3f","https://git.kernel.org/stable/c/89f22f129696ab53cfbc608e0a2184d0fea46ac1"],"weaknesses":[],"ingestedAt":"2026-10-29T19:49:19.404Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2021/47xxx/CVE-2021-47201.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2021-47201","state":"PUBLISHED","datePublished":"2024-04-10T18:56:35.774Z","dateUpdated":"2026-08-05T08:46:42.381Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-03-25T09:12:14.117Z"},"containers":{"cna":{"title":"iavf: free q_vectors before queues in iavf_disable_vf","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\niavf: free q_vectors before queues in iavf_disable_vf\n\niavf_free_queues() clears adapter->num_active_queues, which\niavf_free_q_vectors() relies on, so swap the order of these two function\ncalls in iavf_disable_vf(). This resolves a panic encountered when the\ninterface is disabled and then later brought up again after PF\ncommunication is restored."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"65c7006f234c9ede887d468f595f259a5c5cc552","status":"affected","lessThan":"926e8c83d4c1c2dac0026637eb0d492df876489e","versionType":"git"},{"version":"65c7006f234c9ede887d468f595f259a5c5cc552","status":"affected","lessThan":"78638b47132244e3934dc5dc79f6372d5ce8e98c","versionType":"git"},{"version":"65c7006f234c9ede887d468f595f259a5c5cc552","status":"affected","lessThan":"9ef6589cac9a8c47f5544ccdf4c498093733bb3f","versionType":"git"},{"version":"65c7006f234c9ede887d468f595f259a5c5cc552","status":"affected","lessThan":"89f22f129696ab53cfbc608e0a2184d0fea46ac1","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/intel/iavf/iavf_main.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.13","versionType":"semver"},{"version":"5.4.162","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.82","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.5","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"5.16","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/intel/iavf/iavf_main.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/926e8c83d4c1c2dac0026637eb0d492df876489e"},{"url":"https://git.kernel.org/stable/c/78638b47132244e3934dc5dc79f6372d5ce8e98c"},{"url":"https://git.kernel.org/stable/c/9ef6589cac9a8c47f5544ccdf4c498093733bb3f"},{"url":"https://git.kernel.org/stable/c/89f22f129696ab53cfbc608e0a2184d0fea46ac1"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The bug is in the iavf VF driver’s local reset/disable path (iavf_reset_task → iavf_disable_vf → iavf_free_q_vectors), reached via local netdev operations such as MTU/ethtool-driven resets or PF-reset handling—not by processing remote packets.\nAC:L - Once iavf_disable_vf runs, freeing q_vectors without netif_napi_del is fully deterministic with no race to win. A local actor can repeatedly schedule VF resets, and in the worst reasonable SR-IOV deployment PF communication failures/restoration (the commit’s own scenario) make this path reachable under attacker-driven reset pressure.\nPR:L - Triggering the reset/reopen path only requires CAP_NET_ADMIN in the netns that owns the VF (e.g. ip link set mtu / ifup). SR-IOV VFs are routinely delegated into tenant/container netnses where that capability is available via user namespaces without init-namespace root.\nUI:N - The attacker schedules resets and can bring the interface back up after PF communication is restored (or recovery proceeds via the watchdog); no separate victim action is required.\nS:U - The dangling napi_struct UAF corrupts kernel heap within the same OS authority that runs iavf. This is standard local kernel compromise/DoS, not a guest-to-host escape or IOMMU boundary bypass.\nC:H - q_vectors (containing napi_structs) are kfree’d while still linked on netdev->napi_list, leaving dangling pointers. An attacker can reoccupy the freed object; subsequent NAPI list walks read attacker-controlled state (as in the related iavf NAPI UAF CVE-2023-53556), enabling high confidentiality impact.\nI:H - Later napi_del/list walks perform list_del_rcu and related writes on the freed napi_struct, yielding arbitrary-write primitives via forged next/prev pointers, sufficient for control-flow hijacking under kernel UAF guidance.\nA:H - The commit documents a kernel panic when the interface is brought back up after PF communication is restored; any walk of the corrupted napi_list (reinit, free_netdev, etc.) can oops/panic the kernel."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T08:46:42.381Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"5.4.162"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"5.10.82"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"5.15.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.13","versionEndExcluding":"5.16"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2021-47201","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2024-04-10T19:51:02.253151Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2024-06-04T17:14:25.949Z"}},{"title":"CVE Program Container","references":[{"url":"https://git.kernel.org/stable/c/926e8c83d4c1c2dac0026637eb0d492df876489e","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/78638b47132244e3934dc5dc79f6372d5ce8e98c","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/9ef6589cac9a8c47f5544ccdf4c498093733bb3f","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/89f22f129696ab53cfbc608e0a2184d0fea46ac1","tags":["x_transferred"]}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2024-08-04T05:32:07.396Z"}}]}}}