| { |
| "containers": { |
| "cna": { |
| "providerMetadata": { |
| "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038" |
| }, |
| "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" |
| } |
| } |
| }, |
| "cveMetadata": { |
| "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038", |
| "cveID": "CVE-2021-47584", |
| "requesterUserId": "gregkh@kernel.org", |
| "serial": "1", |
| "state": "PUBLISHED" |
| }, |
| "dataType": "CVE_RECORD", |
| "dataVersion": "5.0" |
| } |
