{"id":"CVE-2026-89809","revision":"c218d35cd1cc4df2bda895f0d4a59765","records":[{"revision":"c218d35cd1cc4df2bda895f0d4a59765","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-89809","aliases":[],"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":0,"publishedAt":"2026-09-16T10:30:42.445+00:00","modifiedAt":"2026-10-19T08:53:03.694+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"e1b73b64271d706079370b58b81292dafd373163\",\n                            \"lessThan\": \"58e866711b234571b0ce342c43d153a4786b32b8\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"e1b73b64271d706079370b58b81292dafd373163\",\n                            \"lessThan\": \"012a026bae0212952b423a842b7e2c0bf21f8e7a\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"7.0\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"7.0\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.5\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/58e866711b234571b0ce342c43d153a4786b32b8","https://git.kernel.org/stable/c/012a026bae0212952b423a842b7e2c0bf21f8e7a"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89809","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-89809","identifiers":["CVE-2026-89809"]},"retained":false,"historicalAffected":[]}],"coverage":[]}