{"id":"CVE-2026-99151","state":"PUBLISHED","title":"drm/amd/display: Fix NULL sink dereference in USB4 bandwidth functions","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amd/display: Fix NULL sink dereference in USB4 bandwidth functions\n\nallocate_usb4_bandwidth_for_stream() and allocate_usb4_bandwidth() both\nuse ASSERT(stream->sink) before dereferencing stream->sink->link. ASSERT\nis compiled out in production builds, so a NULL stream->sink causes a\nNULL pointer dereference.\n\nlink_set_dpms_off() already guards two earlier accesses to stream->sink\nwith explicit NULL checks, confirming that stream->sink can legitimately\nbe NULL. The subsequent call to deallocate_usb4_bandwidth() had no\nequivalent guard.\n\nReplace the ASSERT() calls with proper NULL checks that return false\nearly, and add a matching stream->sink guard at the call site in\nlink_set_dpms_off() consistent with the surrounding pattern.\n\nv2: Keep the existing ASSERT() calls for diagnostics (to report\n    unexpected NULL sink), and add explicit NULL checks that return false\n    before dereferencing stream->sink. Also add a matching stream->sink\n    guard at the deallocation call site in link_set_dpms_off(). (Alex)\n\n(cherry picked from commit 98029a0ce61feb52c563f65349dd9b25f672e355)","publishedAt":"2026-10-28T10:35:06.866Z","updatedAt":"2026-10-28T10:35:06.866Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"0b1eebd359685dd681f6e0df5540a5bb985a27bf","status":"affected","lessThan":"4c8b5e5b9776ad08138d79b14238c5742b32911b","versionType":"git"},{"version":"8fa813b7fd1eccbed13e126166cf764f1f11a7d3","status":"affected","lessThan":"55a67aa89342545b89f469dea6f29bfb6fac6f3d","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/amd/display/dc/link/link_dpms.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"7.2.9","status":"affected","lessThan":"7.2.13","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/amd/display/dc/link/link_dpms.c"]}],"references":["https://git.kernel.org/stable/c/4c8b5e5b9776ad08138d79b14238c5742b32911b","https://git.kernel.org/stable/c/55a67aa89342545b89f469dea6f29bfb6fac6f3d"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/99xxx/CVE-2026-99151.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-99151","state":"PUBLISHED","datePublished":"2026-10-28T10:35:06.866Z","dateUpdated":"2026-10-28T10:35:06.866Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:25:14.396Z"},"containers":{"cna":{"title":"drm/amd/display: Fix NULL sink dereference in USB4 bandwidth functions","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amd/display: Fix NULL sink dereference in USB4 bandwidth functions\n\nallocate_usb4_bandwidth_for_stream() and allocate_usb4_bandwidth() both\nuse ASSERT(stream->sink) before dereferencing stream->sink->link. ASSERT\nis compiled out in production builds, so a NULL stream->sink causes a\nNULL pointer dereference.\n\nlink_set_dpms_off() already guards two earlier accesses to stream->sink\nwith explicit NULL checks, confirming that stream->sink can legitimately\nbe NULL. The subsequent call to deallocate_usb4_bandwidth() had no\nequivalent guard.\n\nReplace the ASSERT() calls with proper NULL checks that return false\nearly, and add a matching stream->sink guard at the call site in\nlink_set_dpms_off() consistent with the surrounding pattern.\n\nv2: Keep the existing ASSERT() calls for diagnostics (to report\n    unexpected NULL sink), and add explicit NULL checks that return false\n    before dereferencing stream->sink. Also add a matching stream->sink\n    guard at the deallocation call site in link_set_dpms_off(). (Alex)\n\n(cherry picked from commit 98029a0ce61feb52c563f65349dd9b25f672e355)"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"0b1eebd359685dd681f6e0df5540a5bb985a27bf","status":"affected","lessThan":"4c8b5e5b9776ad08138d79b14238c5742b32911b","versionType":"git"},{"version":"8fa813b7fd1eccbed13e126166cf764f1f11a7d3","status":"affected","lessThan":"55a67aa89342545b89f469dea6f29bfb6fac6f3d","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/amd/display/dc/link/link_dpms.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"7.2.9","status":"affected","lessThan":"7.2.13","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/gpu/drm/amd/display/dc/link/link_dpms.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/4c8b5e5b9776ad08138d79b14238c5742b32911b"},{"url":"https://git.kernel.org/stable/c/55a67aa89342545b89f469dea6f29bfb6fac6f3d"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-28T10:35:06.866Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.2.9","versionEndExcluding":"7.2.13"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}