{"id":"CVE-2026-97496","state":"PUBLISHED","title":"drm/amdkfd: Fix OOB memory exposure in get_wave_state()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amdkfd: Fix OOB memory exposure in get_wave_state()\n\nThe get_wave_state() function for v9 trusts cp_hqd_cntl_stack_size and\ncp_hqd_cntl_stack_offset values read directly from the MQD, which are\nwritten by GPU microcode and fully attacker-controlled on the\nCRIU-restore path (via AMDKFD_IOC_RESTORE_PROCESS with H3).\n\nthis leads to an unbounded copy_to_user() that can leak adjacent\nGTT/kernel memory. If offset > size, integer underflow produces a ~4 GiB\nread length, if size is set to 1 MiB against a 4 KiB allocation, we leak\n1 MiB of adjacent kernel memory (other queues' MQDs, ring buffers, KASLR\npointers).\n\nFix by clamping both cp_hqd_cntl_stack_size to the actual allocated\nbuffer size (q->ctl_stack_size) and cp_hqd_cntl_stack_offset to the\nclamped size before performing arithmetic and copy_to_user().\n\nThis ensures we never read beyond the allocated kernel BO regardless of\nattacker-supplied MQD field values.","publishedAt":"2026-09-24T16:04:43.625Z","updatedAt":"2026-10-03T10:58:59.453Z","severity":{"score":7.1,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"42c6c48214b726c30918e8dc80e2168607d13ae4","status":"affected","lessThan":"e2bef0f168be46692a6b900916ff5da3771480ed","versionType":"git"},{"version":"42c6c48214b726c30918e8dc80e2168607d13ae4","status":"affected","lessThan":"d9183d974ddd5f09d029beaf359275ac20d4d5fe","versionType":"git"},{"version":"42c6c48214b726c30918e8dc80e2168607d13ae4","status":"affected","lessThan":"ec646686613d8ab05b282d1463a7baa49fd6b83b","versionType":"git"},{"version":"42c6c48214b726c30918e8dc80e2168607d13ae4","status":"affected","lessThan":"7ef144458f48d5589e36f1b3d83e83db2e5c5ba5","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_v9.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.18","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.18","versionType":"semver"},{"version":"6.6.158","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.111","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.53","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_v9.c"]}],"references":["https://git.kernel.org/stable/c/e2bef0f168be46692a6b900916ff5da3771480ed","https://git.kernel.org/stable/c/d9183d974ddd5f09d029beaf359275ac20d4d5fe","https://git.kernel.org/stable/c/ec646686613d8ab05b282d1463a7baa49fd6b83b","https://git.kernel.org/stable/c/7ef144458f48d5589e36f1b3d83e83db2e5c5ba5"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/97xxx/CVE-2026-97496.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-97496","state":"PUBLISHED","datePublished":"2026-09-24T16:04:43.625Z","dateUpdated":"2026-10-03T10:58:59.453Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-24T16:01:01.150Z"},"containers":{"cna":{"title":"drm/amdkfd: Fix OOB memory exposure in get_wave_state()","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amdkfd: Fix OOB memory exposure in get_wave_state()\n\nThe get_wave_state() function for v9 trusts cp_hqd_cntl_stack_size and\ncp_hqd_cntl_stack_offset values read directly from the MQD, which are\nwritten by GPU microcode and fully attacker-controlled on the\nCRIU-restore path (via AMDKFD_IOC_RESTORE_PROCESS with H3).\n\nthis leads to an unbounded copy_to_user() that can leak adjacent\nGTT/kernel memory. If offset > size, integer underflow produces a ~4 GiB\nread length, if size is set to 1 MiB against a 4 KiB allocation, we leak\n1 MiB of adjacent kernel memory (other queues' MQDs, ring buffers, KASLR\npointers).\n\nFix by clamping both cp_hqd_cntl_stack_size to the actual allocated\nbuffer size (q->ctl_stack_size) and cp_hqd_cntl_stack_offset to the\nclamped size before performing arithmetic and copy_to_user().\n\nThis ensures we never read beyond the allocated kernel BO regardless of\nattacker-supplied MQD field values."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"42c6c48214b726c30918e8dc80e2168607d13ae4","status":"affected","lessThan":"e2bef0f168be46692a6b900916ff5da3771480ed","versionType":"git"},{"version":"42c6c48214b726c30918e8dc80e2168607d13ae4","status":"affected","lessThan":"d9183d974ddd5f09d029beaf359275ac20d4d5fe","versionType":"git"},{"version":"42c6c48214b726c30918e8dc80e2168607d13ae4","status":"affected","lessThan":"ec646686613d8ab05b282d1463a7baa49fd6b83b","versionType":"git"},{"version":"42c6c48214b726c30918e8dc80e2168607d13ae4","status":"affected","lessThan":"7ef144458f48d5589e36f1b3d83e83db2e5c5ba5","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_v9.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.18","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.18","versionType":"semver"},{"version":"6.6.158","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.111","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.53","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_v9.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/e2bef0f168be46692a6b900916ff5da3771480ed"},{"url":"https://git.kernel.org/stable/c/d9183d974ddd5f09d029beaf359275ac20d4d5fe"},{"url":"https://git.kernel.org/stable/c/ec646686613d8ab05b282d1463a7baa49fd6b83b"},{"url":"https://git.kernel.org/stable/c/7ef144458f48d5589e36f1b3d83e83db2e5c5ba5"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","baseScore":7.1,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - Attacker-controlled cp_hqd_cntl_stack_size/offset enter via AMDKFD_IOC_CRIU_OP KFD_CRIU_OP_RESTORE (kfd_ioctl_criu → criu_restore → kfd_criu_restore_queue → restore_mqd memcpy of the user MQD), then v9 get_wave_state() runs from kfd_ioctl_get_queue_wave_state (AMDKFD_IOC_GET_QUEUE_WAVE_STATE) on /dev/kfd; no remote protocol carries those fields.\nAC:L - restore_mqd() installs the crafted MQD then sets qp->is_active=0, so AMDKFD_IOC_GET_QUEUE_WAVE_STATE deterministically passes dqm get_wave_state()'s !is_active and cwsr_enabled checks (cwsr_enable defaults to 1) and v9 get_wave_state() copy_to_user()s using unclamped size-offset; no race or firmware quirk is required.\nPR:L - AMDKFD_IOC_GET_QUEUE_WAVE_STATE has ioctl flags 0, but the MQD size/offset that make get_wave_state() over-read are attacker-controlled only after KFD_CRIU_OP_RESTORE; kfd_ioctl() admits that op only with capable(CAP_CHECKPOINT_RESTORE) or capable(CAP_SYS_ADMIN), a delegated non-root cap routinely granted to CRIU/container checkpoint services.\nUI:N - The attacker opens /dev/kfd and issues KFD_CRIU_OP_RESTORE then AMDKFD_IOC_GET_QUEUE_WAVE_STATE against its own KFD process; no other user must mount a filesystem, open a file, or otherwise interact.\nS:U - The unbounded copy_to_user() from the kernel MQD control-stack BO in v9 get_wave_state() discloses host kernel/GTT memory inside the same kernel security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - Pre-fix v9 get_wave_state() copy_to_user()s (cp_hqd_cntl_stack_size - cp_hqd_cntl_stack_offset) bytes from mqd+AMDGPU_GPU_PAGE_SIZE without clamping to q->ctl_stack_size, so a restored 1MiB size against a 4KiB allocate_mqd() BO (or offset>size underflow to ~4GiB) dumps adjacent GTT/kernel memory including other MQDs and KASLR pointers.\nI:N - The defective operation is copy_to_user() from the kernel control-stack BO to the caller's ctl_stack_address; restore_mqd() writes only sizeof(struct v9_mqd) plus ctl_stack_size into the buffer allocate_mqd() sized from q->ctl_stack_size, so this bug does not modify kernel memory out of bounds.\nA:H - A restored cp_hqd_cntl_stack_size of ~1MiB or an offset>size underflow to ~4GiB makes get_wave_state() copy_to_user() walk off the small kmap/vmap GTT/VRAM BO into unmapped kernel VA (and can trip CONFIG_HARDENED_USERCOPY), producing a kernel oops."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-03T10:58:59.453Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.18","versionEndExcluding":"6.6.158"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.18","versionEndExcluding":"6.12.111"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.18","versionEndExcluding":"6.18.53"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.18","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}