{"api_version":"1","generated_at":"2026-09-17T07:14:42+00:00","cve":"CVE-2026-89809","urls":{"html":"https://cve.report/CVE-2026-89809","api":"https://cve.report/api/cve/CVE-2026-89809.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-89809","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-89809"},"summary":{"title":"drm/amdkfd: fix scope of mqd_mgr dereference in pqm_debugfs_mqds","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amdkfd: fix scope of mqd_mgr dereference in pqm_debugfs_mqds\n\nReading /sys/kernel/debug/kfd/mqds while a process holds an active KFD\nqueue triggers a NULL pointer dereference because the for loop that\ncalls mqd_mgr->debugfs_show_mqd() is incorrectly placed outside the\nif (pqn->q) block that initializes mqd_mgr.\n\nThe queue list can contain entries where pqn->q is NULL (kernel queues\nwhere only pqn->kq is valid). In the original code:\n\n  if (pqn->q) {\n      ...\n      mqd_mgr = q->device->dqm->mqd_mgrs[mqd_type];\n      size = mqd_mgr->mqd_stride(...);\n  }\n\n  for (xcc = 0; xcc < num_xccs; xcc++) {  // WRONG: outside if block\n      mqd = q->mqd + size * xcc;\n      r = mqd_mgr->debugfs_show_mqd(m, mqd);\n  }\n\nWhen iterating over a queue node where pqn->q is NULL:\n1. The if (pqn->q) block is skipped\n2. mqd_mgr remains uninitialized (NULL from declaration)\n3. The for loop executes anyway\n4. mqd_mgr->debugfs_show_mqd(m, mqd) dereferences NULL\n\nThe crash manifests as:\n\n  BUG: kernel NULL pointer dereference, address: 0000000000000000\n  #PF: supervisor instruction fetch in kernel mode\n  RIP: 0010:0x0\n  Call Trace:\n   pqm_debugfs_mqds+0x10c/0x1d0 [amdgpu]\n   kfd_debugfs_mqds_by_process+0x9b/0x110 [amdgpu]\n   seq_read_iter+0x132/0x4b0\n   ...\n\nFix by moving the for loop inside the if (pqn->q) block, so mqd_mgr\nand related variables are only used when properly initialized.\n\n(cherry picked from commit 8bfe29d5c798940f797aa24135d2734c3ffce9de)","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-16 11:16:46","updated_at":"2026-09-16 11:16:46"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/58e866711b234571b0ce342c43d153a4786b32b8","name":"https://git.kernel.org/stable/c/58e866711b234571b0ce342c43d153a4786b32b8","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/012a026bae0212952b423a842b7e2c0bf21f8e7a","name":"https://git.kernel.org/stable/c/012a026bae0212952b423a842b7e2c0bf21f8e7a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89809","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89809","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 58e866711b234571b0ce342c43d153a4786b32b8 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 012a026bae0212952b423a842b7e2c0bf21f8e7a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7.2.5 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.5 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc2 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"58e866711b234571b0ce342c43d153a4786b32b8","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"012a026bae0212952b423a842b7e2c0bf21f8e7a","status":"affected","version":"1da177e4c3f41524e886b7f1b8a0c1fc7321cac2","versionType":"git"},{"lessThan":"7.2.5","status":"affected","version":"0","versionType":"semver"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.5","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc2","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.5","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc2","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amdkfd: fix scope of mqd_mgr dereference in pqm_debugfs_mqds\n\nReading /sys/kernel/debug/kfd/mqds while a process holds an active KFD\nqueue triggers a NULL pointer dereference because the for loop that\ncalls mqd_mgr->debugfs_show_mqd() is incorrectly placed outside the\nif (pqn->q) block that initializes mqd_mgr.\n\nThe queue list can contain entries where pqn->q is NULL (kernel queues\nwhere only pqn->kq is valid). In the original code:\n\n  if (pqn->q) {\n      ...\n      mqd_mgr = q->device->dqm->mqd_mgrs[mqd_type];\n      size = mqd_mgr->mqd_stride(...);\n  }\n\n  for (xcc = 0; xcc < num_xccs; xcc++) {  // WRONG: outside if block\n      mqd = q->mqd + size * xcc;\n      r = mqd_mgr->debugfs_show_mqd(m, mqd);\n  }\n\nWhen iterating over a queue node where pqn->q is NULL:\n1. The if (pqn->q) block is skipped\n2. mqd_mgr remains uninitialized (NULL from declaration)\n3. The for loop executes anyway\n4. mqd_mgr->debugfs_show_mqd(m, mqd) dereferences NULL\n\nThe crash manifests as:\n\n  BUG: kernel NULL pointer dereference, address: 0000000000000000\n  #PF: supervisor instruction fetch in kernel mode\n  RIP: 0010:0x0\n  Call Trace:\n   pqm_debugfs_mqds+0x10c/0x1d0 [amdgpu]\n   kfd_debugfs_mqds_by_process+0x9b/0x110 [amdgpu]\n   seq_read_iter+0x132/0x4b0\n   ...\n\nFix by moving the for loop inside the if (pqn->q) block, so mqd_mgr\nand related variables are only used when properly initialized.\n\n(cherry picked from commit 8bfe29d5c798940f797aa24135d2734c3ffce9de)"}],"providerMetadata":{"dateUpdated":"2026-09-16T10:30:42.445Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/58e866711b234571b0ce342c43d153a4786b32b8"},{"url":"https://git.kernel.org/stable/c/012a026bae0212952b423a842b7e2c0bf21f8e7a"}],"title":"drm/amdkfd: fix scope of mqd_mgr dereference in pqm_debugfs_mqds","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-89809","datePublished":"2026-09-16T10:30:42.445Z","dateReserved":"2026-09-11T19:38:34.767Z","dateUpdated":"2026-09-16T10:30:42.445Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-16 11:16:46","lastModifiedDate":"2026-09-16 11:16:46","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"89809","Ordinal":"1","Title":"drm/amdkfd: fix scope of mqd_mgr dereference in pqm_debugfs_mqds","CVE":"CVE-2026-89809","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"89809","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amdkfd: fix scope of mqd_mgr dereference in pqm_debugfs_mqds\n\nReading /sys/kernel/debug/kfd/mqds while a process holds an active KFD\nqueue triggers a NULL pointer dereference because the for loop that\ncalls mqd_mgr->debugfs_show_mqd() is incorrectly placed outside the\nif (pqn->q) block that initializes mqd_mgr.\n\nThe queue list can contain entries where pqn->q is NULL (kernel queues\nwhere only pqn->kq is valid). In the original code:\n\n  if (pqn->q) {\n      ...\n      mqd_mgr = q->device->dqm->mqd_mgrs[mqd_type];\n      size = mqd_mgr->mqd_stride(...);\n  }\n\n  for (xcc = 0; xcc < num_xccs; xcc++) {  // WRONG: outside if block\n      mqd = q->mqd + size * xcc;\n      r = mqd_mgr->debugfs_show_mqd(m, mqd);\n  }\n\nWhen iterating over a queue node where pqn->q is NULL:\n1. The if (pqn->q) block is skipped\n2. mqd_mgr remains uninitialized (NULL from declaration)\n3. The for loop executes anyway\n4. mqd_mgr->debugfs_show_mqd(m, mqd) dereferences NULL\n\nThe crash manifests as:\n\n  BUG: kernel NULL pointer dereference, address: 0000000000000000\n  #PF: supervisor instruction fetch in kernel mode\n  RIP: 0010:0x0\n  Call Trace:\n   pqm_debugfs_mqds+0x10c/0x1d0 [amdgpu]\n   kfd_debugfs_mqds_by_process+0x9b/0x110 [amdgpu]\n   seq_read_iter+0x132/0x4b0\n   ...\n\nFix by moving the for loop inside the if (pqn->q) block, so mqd_mgr\nand related variables are only used when properly initialized.\n\n(cherry picked from commit 8bfe29d5c798940f797aa24135d2734c3ffce9de)","Type":"Description","Title":"drm/amdkfd: fix scope of mqd_mgr dereference in pqm_debugfs_mqds"}]}}}