{"id":"CVE-2021-47087","state":"PUBLISHED","title":"tee: optee: Fix incorrect page free bug","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ntee: optee: Fix incorrect page free bug\n\nPointer to the allocated pages (struct page *page) has already\nprogressed towards the end of allocation. It is incorrect to perform\n__free_pages(page, order) using this pointer as we would free any\narbitrary pages. Fix this by stop modifying the page pointer.","publishedAt":"2024-03-04T18:10:17.107Z","updatedAt":"2026-08-05T08:45:56.013Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"3c712f14d8a9354a8807c15c64c8dd334499cc42","status":"affected","lessThan":"806142c805cacd098e61bdc0f72c778a2389fe4a","versionType":"git"},{"version":"1340dc3fb75ea69221f4f5dcb0cbace55ad0331c","status":"affected","lessThan":"ad338d825e3f7b96ee542bf313728af2d19fe9ad","versionType":"git"},{"version":"ec185dd3ab257dc2a60953fdf1b6622f524cc5b7","status":"affected","lessThan":"91e94e42f6fc49635f1a16d8ae3f79552bcfda29","versionType":"git"},{"version":"ec185dd3ab257dc2a60953fdf1b6622f524cc5b7","status":"affected","lessThan":"18549bf4b21c739a9def39f27dcac53e27286ab5","versionType":"git"},{"version":"255e17923b22cb7abd026e044416d61f6bd0eec0","status":"affected","versionType":"git"},{"version":"5.4.140","status":"affected","lessThan":"5.4.169","versionType":"semver"},{"version":"5.10.58","status":"affected","lessThan":"5.10.89","versionType":"semver"},{"version":"5.13.10","status":"affected","lessThan":"5.14","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/tee/optee/core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.14","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.14","versionType":"semver"},{"version":"5.4.169","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.89","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.12","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"5.16","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/tee/optee/core.c"]}],"references":["https://git.kernel.org/stable/c/806142c805cacd098e61bdc0f72c778a2389fe4a","https://git.kernel.org/stable/c/ad338d825e3f7b96ee542bf313728af2d19fe9ad","https://git.kernel.org/stable/c/91e94e42f6fc49635f1a16d8ae3f79552bcfda29","https://git.kernel.org/stable/c/18549bf4b21c739a9def39f27dcac53e27286ab5"],"weaknesses":[],"ingestedAt":"2026-10-29T19:49:19.404Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2021/47xxx/CVE-2021-47087.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2021-47087","state":"PUBLISHED","datePublished":"2024-03-04T18:10:17.107Z","dateUpdated":"2026-08-05T08:45:56.013Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-02-29T22:33:44.299Z"},"containers":{"cna":{"title":"tee: optee: Fix incorrect page free bug","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ntee: optee: Fix incorrect page free bug\n\nPointer to the allocated pages (struct page *page) has already\nprogressed towards the end of allocation. It is incorrect to perform\n__free_pages(page, order) using this pointer as we would free any\narbitrary pages. Fix this by stop modifying the page pointer."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"3c712f14d8a9354a8807c15c64c8dd334499cc42","status":"affected","lessThan":"806142c805cacd098e61bdc0f72c778a2389fe4a","versionType":"git"},{"version":"1340dc3fb75ea69221f4f5dcb0cbace55ad0331c","status":"affected","lessThan":"ad338d825e3f7b96ee542bf313728af2d19fe9ad","versionType":"git"},{"version":"ec185dd3ab257dc2a60953fdf1b6622f524cc5b7","status":"affected","lessThan":"91e94e42f6fc49635f1a16d8ae3f79552bcfda29","versionType":"git"},{"version":"ec185dd3ab257dc2a60953fdf1b6622f524cc5b7","status":"affected","lessThan":"18549bf4b21c739a9def39f27dcac53e27286ab5","versionType":"git"},{"version":"255e17923b22cb7abd026e044416d61f6bd0eec0","status":"affected","versionType":"git"},{"version":"5.4.140","status":"affected","lessThan":"5.4.169","versionType":"semver"},{"version":"5.10.58","status":"affected","lessThan":"5.10.89","versionType":"semver"},{"version":"5.13.10","status":"affected","lessThan":"5.14","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/tee/optee/core.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.14","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.14","versionType":"semver"},{"version":"5.4.169","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.89","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.12","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"5.16","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/tee/optee/core.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/806142c805cacd098e61bdc0f72c778a2389fe4a"},{"url":"https://git.kernel.org/stable/c/ad338d825e3f7b96ee542bf313728af2d19fe9ad"},{"url":"https://git.kernel.org/stable/c/91e94e42f6fc49635f1a16d8ae3f79552bcfda29"},{"url":"https://git.kernel.org/stable/c/18549bf4b21c739a9def39f27dcac53e27286ab5"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - Reachable only via local ioctl (TEE_IOC_SHM_ALLOC) on /dev/tee[0-9]*, the OP-TEE client character device; not exposed over the network.\nAC:L - An attacker who can open the TEE client device can reliably force the shm_register failure path (e.g., by exhausting OP-TEE dynamic SHM registration capacity or inducing allocation failure after alloc_pages succeeds), which triggers the incorrect __free_pages().\nPR:L - /dev/tee0 is the unprivileged client interface with no capability check in the driver; access is DAC-only and commonly granted to non-root teeclnt/group users or TEE client apps on Android/embedded deployments.\nUI:N - Exploitation requires only opening the device and issuing TEE_IOC_SHM_ALLOC; no victim action is needed.\nS:U - The incorrect free corrupts Normal-World kernel memory within the same OS security authority; this is standard local kernel privilege escalation, not a TrustZone/VM boundary escape.\nC:H - __free_pages() on the advanced page pointer frees unrelated in-use pages, enabling use-after-free of attacker-influenced heap objects and arbitrary kernel memory disclosure.\nI:H - Arbitrary page free yields classic UAF/heap corruption primitives that can be turned into arbitrary write and control-flow hijacking in the kernel.\nA:H - Freeing pages still owned by other kernel allocations causes oops/panic or allocator corruption and can crash the system even without a full exploit."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T08:45:56.013Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.4.140","versionEndExcluding":"5.4.169"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10.58","versionEndExcluding":"5.10.89"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.14","versionEndExcluding":"5.15.12"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.14","versionEndExcluding":"5.16"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.13.10"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2021-47087","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2024-03-06T20:26:26.296406Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2024-06-04T17:13:35.356Z"}},{"title":"CVE Program Container","references":[{"url":"https://git.kernel.org/stable/c/806142c805cacd098e61bdc0f72c778a2389fe4a","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/ad338d825e3f7b96ee542bf313728af2d19fe9ad","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/91e94e42f6fc49635f1a16d8ae3f79552bcfda29","tags":["x_transferred"]},{"url":"https://git.kernel.org/stable/c/18549bf4b21c739a9def39f27dcac53e27286ab5","tags":["x_transferred"]}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2024-08-04T05:24:39.851Z"}}]}}}