Show plain JSON{"dataType": "CVE_RECORD", "dataVersion": "5.1", "cveMetadata": {"cveId": "CVE-2021-47584", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-05-24T15:11:00.731Z", "datePublished": "2024-06-19T14:53:50.119Z", "dateUpdated": "2025-05-04T07:14:10.080Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2025-05-04T07:14:10.080Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\niocost: Fix divide-by-zero on donation from low hweight cgroup\n\nThe donation calculation logic assumes that the donor has non-zero\nafter-donation hweight, so the lowest active hweight a donating cgroup can\nhave is 2 so that it can donate 1 while keeping the other 1 for itself.\nEarlier, we only donated from cgroups with sizable surpluses so this\ncondition was always true. However, with the precise donation algorithm\nimplemented, f1de2439ec43 (\"blk-iocost: revamp donation amount\ndetermination\") made the donation amount calculation exact enabling even low\nhweight cgroups to donate.\n\nThis means that in rare occasions, a cgroup with active hweight of 1 can\nenter donation calculation triggering the following warning and then a\ndivide-by-zero oops.\n\n WARNING: CPU: 4 PID: 0 at block/blk-iocost.c:1928 transfer_surpluses.cold+0x0/0x53 [884/94867]\n ...\n RIP: 0010:transfer_surpluses.cold+0x0/0x53\n Code: 92 ff 48 c7 c7 28 d1 ab b5 65 48 8b 34 25 00 ae 01 00 48 81 c6 90 06 00 00 e8 8b 3f fe ff 48 c7 c0 ea ff ff ff e9 95 ff 92 ff <0f> 0b 48 c7 c7 30 da ab b5 e8 71 3f fe ff 4c 89 e8 4d 85 ed 74 0\n4\n ...\n Call Trace:\n <IRQ>\n ioc_timer_fn+0x1043/0x1390\n call_timer_fn+0xa1/0x2c0\n __run_timers.part.0+0x1ec/0x2e0\n run_timer_softirq+0x35/0x70\n ...\n iocg: invalid donation weights in /a/b: active=1 donating=1 after=0\n\nFix it by excluding cgroups w/ active hweight < 2 from donating. Excluding\nthese extreme low hweight donations shouldn't affect work conservation in\nany meaningful way."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["block/blk-iocost.c"], "versions": [{"version": "f1de2439ec43b74764f2a26e3a310b24407e3bde", "lessThan": "a7c80674538f15f85d68138240aae440b8039519", "status": "affected", "versionType": "git"}, {"version": "f1de2439ec43b74764f2a26e3a310b24407e3bde", "lessThan": "3a1a4eb574178c21241a6200f4785572e661c472", "status": "affected", "versionType": "git"}, {"version": "f1de2439ec43b74764f2a26e3a310b24407e3bde", "lessThan": "edaa26334c117a584add6053f48d63a988d25a6e", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["block/blk-iocost.c"], "versions": [{"version": "5.10", "status": "affected"}, {"version": "0", "lessThan": "5.10", "status": "unaffected", "versionType": "semver"}, {"version": "5.10.88", "lessThanOrEqual": "5.10.*", "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": "5.10", "versionEndExcluding": "5.10.88"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "5.15.11"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.10", "versionEndExcluding": "5.16"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/a7c80674538f15f85d68138240aae440b8039519"}, {"url": "https://git.kernel.org/stable/c/3a1a4eb574178c21241a6200f4785572e661c472"}, {"url": "https://git.kernel.org/stable/c/edaa26334c117a584add6053f48d63a988d25a6e"}], "title": "iocost: Fix divide-by-zero on donation from low hweight cgroup", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2024-06-20T19:43:49.047356Z", "id": "CVE-2021-47584", "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": "2024-06-20T19:43:55.927Z"}}, {"providerMetadata": {"orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2024-08-04T05:39:59.857Z"}, "title": "CVE Program Container", "references": [{"url": "https://git.kernel.org/stable/c/a7c80674538f15f85d68138240aae440b8039519", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/3a1a4eb574178c21241a6200f4785572e661c472", "tags": ["x_transferred"]}, {"url": "https://git.kernel.org/stable/c/edaa26334c117a584add6053f48d63a988d25a6e", "tags": ["x_transferred"]}]}]}}