{"cve":"CVE-2021-47559","nvd":{"published":"2024-05-24T15:15:20.537","modified":"2026-08-04T10:17:08.870","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/smc: Fix NULL pointer dereferencing in smc_vlan_by_tcpsk()\n\nCoverity reports a possible NULL dereferencing problem:\n\nin smc_vlan_by_tcpsk():\n6. returned_null: netdev_lower_get_next returns NULL (checked 29 out of 30 times).\n7. var_assigned: Assigning: ndev = NULL return value from netdev_lower_get_next.\n1623                ndev = (struct net_device *)netdev_lower_get_next(ndev, &lower);\nCID 1468509 (#1 of 1): Dereference null return value (NULL_RETURNS)\n8. dereference: Dereferencing a pointer that might be NULL ndev when calling is_vlan_dev.\n1624                if (is_vlan_dev(ndev)) {\n\nRemove the manual implementation and use netdev_walk_all_lower_dev() to\niterate over the lower devices. While on it remove an obsolete function\nparameter comment.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-476"],"references":["https://git.kernel.org/stable/c/587acad41f1bc48e16f42bb2aca63bf323380be8","https://git.kernel.org/stable/c/bb851d0fb02547d03cd40106b5f2391c4fed6ed1","https://git.kernel.org/stable/c/c94cbd262b6aa3b54d73a1ed1f9c0d19df57f4ff","https://git.kernel.org/stable/c/587acad41f1bc48e16f42bb2aca63bf323380be8","https://git.kernel.org/stable/c/bb851d0fb02547d03cd40106b5f2391c4fed6ed1"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:50:30.954589733+00:00"},"epss":{"cve":"CVE-2021-47559","score":0.00468,"percentile":0.4051,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}