{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-23195", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-01-13T15:37:45.985Z", "datePublished": "2026-02-14T16:27:21.621Z", "dateUpdated": "2026-08-05T12:20:36.969Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:20:36.969Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncgroup/dmem: avoid pool UAF\n\nAn UAF issue was observed:\n\nBUG: KASAN: slab-use-after-free in page_counter_uncharge+0x65/0x150\nWrite of size 8 at addr ffff888106715440 by task insmod/527\n\nCPU: 4 UID: 0 PID: 527 Comm: insmod 6.19.0-rc7-next-20260129+ #11\nTainted: [O]=OOT_MODULE\nCall Trace:\n\ndump_stack_lvl+0x82/0xd0\nkasan_report+0xca/0x100\nkasan_check_range+0x39/0x1c0\npage_counter_uncharge+0x65/0x150\ndmem_cgroup_uncharge+0x1f/0x260\n\nAllocated by task 527:\n\nFreed by task 0:\n\nThe buggy address belongs to the object at ffff888106715400\nwhich belongs to the cache kmalloc-512 of size 512\nThe buggy address is located 64 bytes inside of\nfreed 512-byte region [ffff888106715400, ffff888106715600)\n\nThe buggy address belongs to the physical page:\n\nMemory state around the buggy address:\nffff888106715300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc\nffff888106715380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc\n>ffff888106715400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb\n\t\t\t\t ^\nffff888106715480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb\nffff888106715500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb\n\nThe issue occurs because a pool can still be held by a caller after its\nassociated memory region is unregistered. The current implementation frees\nthe pool even if users still hold references to it (e.g., before uncharge\noperations complete).\n\nThis patch adds a reference counter to each pool, ensuring that a pool is\nonly freed when its reference count drops to zero." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerability is triggered through local DRM device ioctls (GPU buffer allocation/deallocation) combined with cgroup device memory accounting. No network or adjacent access path exists.\nAC:H - An unprivileged attacker can hold GPU memory charges, but triggering the UAF requires a device removal event (module unload, device unbind) which is beyond the unprivileged attacker's control. The attacker cannot independently cause region unregistration.\nPR:L - An unprivileged local user with DRM device access (e.g., /dev/dri/renderD128, commonly accessible to video group users) can allocate GPU buffers that hold cgroup charge references, setting up the UAF condition exploitable when device removal occurs.\nUI:N - No user interaction is required. The attacker's process holds GPU allocations, and the UAF triggers automatically when the device is removed and cleanup runs.\nS:U - The vulnerability stays within the kernel's security authority. There is no crossing of a security boundary such as VM escape or IOMMU bypass.\nC:H - The UAF dereferences the parent pointer chain in freed page_counter structures, reading from freed/reallocated memory. An attacker who heap-sprays the freed kmalloc-512 slot can leak kernel data through the pointer-following behavior.\nI:H - The page_counter_uncharge performs atomic_long_sub_return on freed memory at a known offset, providing a controlled write primitive. Following the parent chain can cause writes at multiple attacker-influenced locations via heap spray.\nA:H - The KASAN report confirms a kernel crash (slab-use-after-free). The write to freed memory causes a kernel oops that crashes the system." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/cgroup/dmem.c" ], "versions": [ { "version": "b168ed458ddecc176f3b9a1f4bcd83d7a4541c14", "lessThan": "d3081353acaa6a638dcf75726066ea556a2de8d5", "status": "affected", "versionType": "git" }, { "version": "b168ed458ddecc176f3b9a1f4bcd83d7a4541c14", "lessThan": "99a2ef500906138ba58093b9893972a5c303c734", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "kernel/cgroup/dmem.c" ], "versions": [ { "version": "6.14", "status": "affected" }, { "version": "0", "lessThan": "6.14", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.10", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.19", "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": "6.14", "versionEndExcluding": "6.18.10" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.14", "versionEndExcluding": "6.19" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/d3081353acaa6a638dcf75726066ea556a2de8d5" }, { "url": "https://git.kernel.org/stable/c/99a2ef500906138ba58093b9893972a5c303c734" } ], "title": "cgroup/dmem: avoid pool UAF", "x_generator": { "engine": "bippy-1.2.0" } } } }