{"id":"CVE-2026-45878","summary":"drm/amdkfd: Fix watch_id bounds checking in debug address watch v2","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amdkfd: Fix watch_id bounds checking in debug address watch v2\n\nThe address watch clear code receives watch_id as an unsigned value\n(u32), but some helper functions were using a signed int and checked\nbits by shifting with watch_id.\n\nIf a very large watch_id is passed from userspace, it can be converted\nto a negative value.  This can cause invalid shifts and may access\nmemory outside the watch_points array.\n\ndrm/amdkfd: Fix watch_id bounds checking in debug address watch v2\n\nFix this by checking that watch_id is within MAX_WATCH_ADDRESSES before\nusing it.  Also use BIT(watch_id) to test and clear bits safely.\n\nThis keeps the behavior unchanged for valid watch IDs and avoids\nundefined behavior for invalid ones.\n\nFixes the below:\ndrivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_debug.c:448\nkfd_dbg_trap_clear_dev_address_watch() error: buffer overflow\n'pdd-\u003ewatch_points' 4 \u003c= u32max user_rl='0-3,2147483648-u32max' uncapped\n\ndrivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_debug.c\n    433 int kfd_dbg_trap_clear_dev_address_watch(struct kfd_process_device *pdd,\n    434                                         uint32_t watch_id)\n    435 {\n    436         int r;\n    437\n    438         if (!kfd_dbg_owns_dev_watch_id(pdd, watch_id))\n\nkfd_dbg_owns_dev_watch_id() doesn't check for negative values so if\nwatch_id is larger than INT_MAX it leads to a buffer overflow.\n(Negative shifts are undefined).\n\n    439                 return -EINVAL;\n    440\n    441         if (!pdd-\u003edev-\u003ekfd-\u003eshared_resources.enable_mes) {\n    442                 r = debug_lock_and_unmap(pdd-\u003edev-\u003edqm);\n    443                 if (r)\n    444                         return r;\n    445         }\n    446\n    447         amdgpu_gfx_off_ctrl(pdd-\u003edev-\u003eadev, false);\n--\u003e 448         pdd-\u003ewatch_points[watch_id] = pdd-\u003edev-\u003ekfd2kgd-\u003eclear_address_watch(\n    449                                                         pdd-\u003edev-\u003eadev,\n    450                                                         watch_id);\n\nv2: (as per, Jonathan Kim)\n - Add early watch_id \u003e= MAX_WATCH_ADDRESSES validation in the set path to\n   match the clear path.\n - Drop the redundant bounds check in kfd_dbg_owns_dev_watch_id().","modified":"2026-07-03T18:29:32.315540326Z","published":"2026-05-27T12:16:49.108Z","related":["SUSE-SU-2026:22108-1","SUSE-SU-2026:22137-1","SUSE-SU-2026:22433-1","SUSE-SU-2026:2482-1","SUSE-SU-2026:2591-1","SUSE-SU-2026:2632-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45878.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/2b36c0c1bcbbe15f6cfa9652084b3124c835a150"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3c38a0f07aa2bfef2b219b1f045534ad93f85afd"},{"type":"WEB","url":"https://git.kernel.org/stable/c/5a19302cab5cec7ae7f1a60c619951e6c17d8742"},{"type":"WEB","url":"https://git.kernel.org/stable/c/971bf8e61e9b4abaacf9b35eaf76ec222758f9d6"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a0d367e13db63a6ed76ee0d0a8c3a58c1fa98488"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45878.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-45878"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"e0f85f4690d089cc1a60337decafb1acf7eec45e"},{"fixed":"971bf8e61e9b4abaacf9b35eaf76ec222758f9d6"},{"fixed":"a0d367e13db63a6ed76ee0d0a8c3a58c1fa98488"},{"fixed":"2b36c0c1bcbbe15f6cfa9652084b3124c835a150"},{"fixed":"3c38a0f07aa2bfef2b219b1f045534ad93f85afd"},{"fixed":"5a19302cab5cec7ae7f1a60c619951e6c17d8742"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-45878.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.5.0"},{"fixed":"6.6.128"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.75"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.14"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"6.19.4"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-45878.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}