{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2021-47592", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-05-24T15:11:00.733Z", "datePublished": "2024-06-19T14:53:55.574Z", "dateUpdated": "2026-05-11T13:57:31.447Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-05-11T13:57:31.447Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: stmmac: fix tc flower deletion for VLAN priority Rx steering\n\nTo replicate the issue:-\n\n1) Add 1 flower filter for VLAN Priority based frame steering:-\n$ IFDEVNAME=eth0\n$ tc qdisc add dev $IFDEVNAME ingress\n$ tc qdisc add dev $IFDEVNAME root mqprio num_tc 8 \\\n map 0 1 2 3 4 5 6 7 0 0 0 0 0 0 0 0 \\\n queues 1@0 1@1 1@2 1@3 1@4 1@5 1@6 1@7 hw 0\n$ tc filter add dev $IFDEVNAME parent ffff: protocol 802.1Q \\\n flower vlan_prio 0 hw_tc 0\n\n2) Get the 'pref' id\n$ tc filter show dev $IFDEVNAME ingress\n\n3) Delete a specific tc flower record (say pref 49151)\n$ tc filter del dev $IFDEVNAME parent ffff: pref 49151\n\nFrom dmesg, we will observe kernel NULL pointer ooops\n\n[ 197.170464] BUG: kernel NULL pointer dereference, address: 0000000000000000\n[ 197.171367] #PF: supervisor read access in kernel mode\n[ 197.171367] #PF: error_code(0x0000) - not-present page\n[ 197.171367] PGD 0 P4D 0\n[ 197.171367] Oops: 0000 [#1] PREEMPT SMP NOPTI\n\n\n\n[ 197.171367] RIP: 0010:tc_setup_cls+0x20b/0x4a0 [stmmac]\n\n\n\n[ 197.171367] Call Trace:\n[ 197.171367] \n[ 197.171367] ? __stmmac_disable_all_queues+0xa8/0xe0 [stmmac]\n[ 197.171367] stmmac_setup_tc_block_cb+0x70/0x110 [stmmac]\n[ 197.171367] tc_setup_cb_destroy+0xb3/0x180\n[ 197.171367] fl_hw_destroy_filter+0x94/0xc0 [cls_flower]\n\nThe above issue is due to previous incorrect implementation of\ntc_del_vlan_flow(), shown below, that uses flow_cls_offload_flow_rule()\nto get struct flow_rule *rule which is no longer valid for tc filter\ndelete operation.\n\n struct flow_rule *rule = flow_cls_offload_flow_rule(cls);\n struct flow_dissector *dissector = rule->match.dissector;\n\nSo, to ensure tc_del_vlan_flow() deletes the right VLAN cls record for\nearlier configured RX queue (configured by hw_tc) in tc_add_vlan_flow(),\nthis patch introduces stmmac_rfs_entry as driver-side flow_cls_offload\nrecord for 'RX frame steering' tc flower, currently used for VLAN\npriority. The implementation has taken consideration for future extension\nto include other type RX frame steering such as EtherType based.\n\nv2:\n - Clean up overly extensive backtrace and rewrite git message to better\n explain the kernel NULL pointer issue." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/ethernet/stmicro/stmmac/stmmac.h", "drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c" ], "versions": [ { "version": "0e039f5cf86ce2fcb62077a163e7ff3d7b7b7cf3", "lessThan": "97cb5c82aa1dd85a39b1bd021c8b5f18af623779", "status": "affected", "versionType": "git" }, { "version": "0e039f5cf86ce2fcb62077a163e7ff3d7b7b7cf3", "lessThan": "aeb7c75cb77478fdbf821628e9c95c4baa9adc63", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/ethernet/stmicro/stmmac/stmmac.h", "drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c" ], "versions": [ { "version": "5.13", "status": "affected" }, { "version": "0", "lessThan": "5.13", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.11", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.16", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.13", "versionEndExcluding": "5.15.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.13", "versionEndExcluding": "5.16" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/97cb5c82aa1dd85a39b1bd021c8b5f18af623779" }, { "url": "https://git.kernel.org/stable/c/aeb7c75cb77478fdbf821628e9c95c4baa9adc63" } ], "title": "net: stmmac: fix tc flower deletion for VLAN priority Rx steering", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "problemTypes": [ { "descriptions": [ { "type": "CWE", "cweId": "CWE-476", "lang": "en", "description": "CWE-476 NULL Pointer Dereference" } ] } ], "metrics": [ { "cvssV3_1": { "scope": "UNCHANGED", "version": "3.1", "baseScore": 5.5, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE" } }, { "other": { "type": "ssvc", "content": { "timestamp": "2024-06-20T15:19:38.436561Z", "id": "CVE-2021-47592", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-11-06T15:17:09.361Z" } }, { "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T05:47:39.480Z" }, "title": "CVE Program Container", "references": [ { "url": "https://git.kernel.org/stable/c/97cb5c82aa1dd85a39b1bd021c8b5f18af623779", "tags": [ "x_transferred" ] }, { "url": "https://git.kernel.org/stable/c/aeb7c75cb77478fdbf821628e9c95c4baa9adc63", "tags": [ "x_transferred" ] } ] } ] } }