{"id":"CVE-2021-47316","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix NULL dereference in nfs3svc_encode_getaclres\n\nIn error cases the dentry may be NULL.\n\nBefore 20798dfe249a, the encoder also checked dentry and\nd_really_is_pos…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix NULL dereference in nfs3svc_encode_getaclres\n\nIn error cases the dentry may be NULL.\n\nBefore 20798dfe249a, the encoder also checked dentry and\nd_really_is_pos…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cwe":["CWE-476"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 5.13, < 5.13.4"],"patched":["linux_kernel 5.13.4"],"published":"2024-05-21","updated":"2026-10-14","sourceUpdated":"2026-10-14T13:17:13.620","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2021-47316","references":[{"url":"https://git.kernel.org/stable/c/650e6f383a6eb40f7c0a010982a74ab4b6893870","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ab1016d39cc052064e32f25ad18ef8767a0ee3b8","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e79057d15d96ef19de4de6d7e479bae3d58a2a8d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/650e6f383a6eb40f7c0a010982a74ab4b6893870","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/ab1016d39cc052064e32f25ad18ef8767a0ee3b8","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/e79057d15d96ef19de4de6d7e479bae3d58a2a8d","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-265688.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-355557.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","cve.org"],"epss":0.00622,"epssPercentile":0.49616,"ingestedAt":"2026-10-14T13:30:58.420Z","ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2024-05-21T18:45:04.809482Z"},"slug":"CVE-2021-47316","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnfsd: fix NULL dereference in nfs3svc_encode_getaclres\n\nIn error cases the dentry may be NULL.\n\nBefore 20798dfe249a, the encoder also checked dentry and\nd_really_is_positive(dentry), but that looks like overkill to me--zero\nstatus should be enough to guarantee a positive dentry.\n\nThis isn't the first time we've seen an error-case NULL dereference\nhidden in the initialization of a local variable in an xdr encoder.  But\nI went back through the other recent rewrites and didn't spot any\nsimilar bugs.\n\n## Affected\n\n- `linux_kernel >= 5.13, < 5.13.4`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 5.13.4`","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}