{"id":"CVE-2026-99004","kind":"vulnerability","aliases":["CVE-2026-99004"],"related":[],"title":"Linux DRM imagination driver: page table sizing bug causes memory exhaustion","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/imagination: Size page table preallocation by device address\n\nCommit 0a8224058a58 (\"drm/imagination: Fix page count for page table for\nmap() interface\") passed the device address to\npvr_mmu_op_context_create(), but the preallocation is still sized from\ndevice_addr + sgt_offset with an exclusive end. The offset into the\nobject's pages has no place in a device-virtual range, and the exclusive\nend allocates one table too many when the range ends on a table\nboundary.\n\nCount the tables from device_addr and the inclusive end of the range.\n\nThe new calculation does not take page table indices into account. This\nfixes another issue with the previous implementation, where the\ndifference between start and end indices could underflow when a mapping\ncrossed a page table boundary. This would lead to the driver\npreallocating a huge number of MMU pages, exhausting system memory and\ntriggering an out of memory panic.\n\n[Alessio: add paragraph to point out OOM bug being fixed, cc stable]","summary":"The Linux kernel's Imagination GPU (drm/imagination) driver sizes its MMU page table preallocation incorrectly when a mapping crosses a page table boundary. The arithmetic can underflow and preallocate a huge number of MMU pages, exhausting system memory and causing an out-of-memory panic.","severity":"unknown","cvss":null,"epss":0.00209,"exploited":false,"exploited_at":null,"products":[],"ecosystems":[],"tags":["arm","embedded","imagination-gpu","linux-kernel","runtime"],"not_affected_if":["driver-not-loaded","no-imagination-gpu"],"how_to_check":"- Check whether the running kernel includes the drm/imagination fix referenced by commit 0a8224058a58 and this follow-up, for example with `uname -r` against your distribution's advisory\n- Check whether the Imagination GPU driver is loaded with `lsmod | grep pvr`\n- Check the affected kernel version range in the NVD entry (https://nvd.nist.gov/vuln/detail/CVE-2026-99004): unknown","fix":"- Update the Linux kernel to a release that includes the drm/imagination page table sizing fix, version unknown from the sources\n- Until patched, unload the pvr driver where it is not needed: unknown","status":"open","published_at":"2026-10-23T13:17:22+00:00","first_seen_at":"2026-10-23T21:57:33+00:00","triaged_at":"2026-10-25T04:55:55+00:00","updated_at":"2026-10-25T12:38:50+00:00","category":"runtime","confidence":0.6,"triage":{"at":"2026-10-25T04:55:55Z","model":"claude-haiku-5-5","output":{"fix":"- Update the Linux kernel to a release that includes the drm/imagination page table sizing fix, version unknown from the sources\n- Until patched, unload the pvr driver where it is not needed: unknown","reach":"local","title":"Linux DRM imagination driver: page table sizing bug causes memory exhaustion","impact":"medium","summary":"The Linux kernel's Imagination GPU (drm/imagination) driver sizes its MMU page table preallocation incorrectly when a mapping crosses a page table boundary. The arithmetic can underflow and preallocate a huge number of MMU pages, exhausting system memory and causing an out-of-memory panic.","category":"runtime","nicknames":[],"who_cares":["linux-kernel","embedded","arm","imagination-gpu"],"confidence":0.6,"needs_auth":"unknown","worst_case":"Driver mapping requests can exhaust system memory and trigger a kernel out-of-memory panic.","analyst_note":"Confirm affected kernel version ranges and the fixed release from the kernel.org stable commits and the NVD entry, and check whether the mapping path is reachable by unprivileged users.","how_to_check":"- Check whether the running kernel includes the drm/imagination fix referenced by commit 0a8224058a58 and this follow-up, for example with `uname -r` against your distribution's advisory\n- Check whether the Imagination GPU driver is loaded with `lsmod | grep pvr`\n- Check the affected kernel version range in the NVD entry (https://nvd.nist.gov/vuln/detail/CVE-2026-99004): unknown","needs_analyst":true,"not_affected_if":["no-imagination-gpu","driver-not-loaded"],"who_is_affected":"Only systems that use the Imagination PowerVR GPU through the drm/imagination kernel driver are exposed, typically certain embedded or ARM boards. Desktop and server systems without this GPU are unlikely to load the driver. The sources do not say which devices or kernel versions are confirmed affected.","user_interaction":"unknown","needs_special_setup":"unknown","severity_if_unknown":"unknown"},"cost_usd":0.000725,"input_tokens":3550,"output_tokens":740,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2026':13A,16A '-99004':14A,17A '0a8224058a58':92C 'account':184C 'add':235C 'addr':121C,166C 'address':90C,106C 'alessio':234C 'alloc':148C 'anoth':187C 'arithmet':51B 'arm':18B 'boundari':49B,160C,210C 'bug':8A,241C 'calcul':176C 'caus':9A,66B 'cc':244C 'commit':91C 'context':111C 'could':201C 'count':96C,161C 'creat':112C 'cross':45B,206C 'cve':12A,15A 'devic':89C,105C,120C,141C,165C 'device-virtu':140C 'differ':195C 'driver':4A,34B,216C 'drm':2A 'drm/imagination':33B,83C,93C 'embed':19B 'end':127C,147C,156C,170C,199C 'exclus':126C,146C 'exhaust':11A,62B,224C 'fix':94C,186C,243C 'follow':78C 'gpu':22B,32B 'huge':57B,219C 'imagin':3A,21B,31B 'imagination-gpu':20B 'implement':192C 'inclus':169C 'incorrect':41B 'indic':182C,200C 'interfac':102C 'issu':188C 'kernel':25B,29B,76C 'lead':213C 'linux':1A,24B,28B,75C 'linux-kernel':23B 'mani':152C 'map':44B,101C,205C 'memori':10A,64B,71B,226C,232C 'mmu':37B,60B,109C,222C 'new':175C 'number':58B,220C 'object':132C 'offset':123C,129C 'one':149C 'oom':240C 'op':110C 'out-of-memori':68B 'page':5A,38B,47B,61B,85C,95C,98C,134C,180C,208C,223C 'panic':72B,233C 'paragraph':236C 'pass':103C 'place':137C 'point':238C 'prealloc':40B,55B,87C,115C,217C 'previous':191C 'pvr':108C 'rang':143C,155C,173C 'resolv':82C 'runtim':26B 'sgt':122C 'size':7A,35B,84C,118C 'stabl':245C 'start':197C 'still':117C 'system':63B,225C 'tabl':6A,39B,48B,86C,99C,150C,159C,163C,181C,209C 'take':179C 'trigger':228C 'underflow':53B,202C 'virtual':142C 'vulner':79C 'would':212C","nicknames":[],"mitigations":[],"who_affected":"Only systems that use the Imagination PowerVR GPU through the drm/imagination kernel driver are exposed, typically certain embedded or ARM boards. Desktop and server systems without this GPU are unlikely to load the driver. The sources do not say which devices or kernel versions are confirmed affected.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-23T13:17:22+00:00","kev":null,"cvss_vector":null,"cvss_by":null,"poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-99004","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-99004","severity":null,"published_at":"2026-10-23T13:17:22+00:00","modified_at":"2026-10-23T13:17:22+00:00","first_seen_at":"2026-10-23T21:57:33+00:00","fetched_at":"2026-10-23T22:29:03+00:00","note":null},{"source":"epss","external_id":"CVE-2026-99004","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-99004","severity":null,"published_at":null,"modified_at":null,"first_seen_at":"2026-10-25T12:38:50+00:00","fetched_at":"2026-10-25T12:38:50+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}