{"id":"CVE-2025-71305","summary":"drm/display/dp_mst: Add protection against 0 vcpi","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/display/dp_mst: Add protection against 0 vcpi\n\nWhen releasing a timeslot there is a slight chance we may end up\nwith the wrong payload mask due to overflow if the delayed_destroy_work\nends up coming into play after a DP 2.1 monitor gets disconnected\nwhich causes vcpi to become 0 then we try to make the payload =\n~BIT(vcpi - 1) which is a negative shift. VCPI id should never\nreally be 0 hence skip changing the payload mask if VCPI is 0.\n\nOtherwise it leads to\n\u003c7\u003e [515.287237] xe 0000:03:00.0: [drm:drm_dp_mst_get_port_malloc\n[drm_display_helper]] port ffff888126ce9000 (3)\n\u003c4\u003e [515.287267] -----------[ cut here ]-----------\n\u003c3\u003e [515.287268] UBSAN: shift-out-of-bounds in\n../drivers/gpu/drm/display/drm_dp_mst_topology.c:4575:36\n\u003c3\u003e [515.287271] shift exponent -1 is negative\n\u003c4\u003e [515.287275] CPU: 7 UID: 0 PID: 3108 Comm: kworker/u64:33 Tainted: G\nS U 6.17.0-rc6-lgci-xe-xe-3795-3e79699fa1b216e92+ #1 PREEMPT(voluntary)\n\u003c4\u003e [515.287279] Tainted: [S]=CPU_OUT_OF_SPEC, [U]=USER\n\u003c4\u003e [515.287279] Hardware name: ASUS System Product Name/PRIME Z790-P\nWIFI, BIOS 1645 03/15/2024\n\u003c4\u003e [515.287281] Workqueue: drm_dp_mst_wq drm_dp_delayed_destroy_work\n[drm_display_helper]\n\u003c4\u003e [515.287303] Call Trace:\n\u003c4\u003e [515.287304] \u003cTASK\u003e\n\u003c4\u003e [515.287306] dump_stack_lvl+0xc1/0xf0\n\u003c4\u003e [515.287313] dump_stack+0x10/0x20\n\u003c4\u003e [515.287316] __ubsan_handle_shift_out_of_bounds+0x133/0x2e0\n\u003c4\u003e [515.287324] ? drm_atomic_get_private_obj_state+0x186/0x1d0\n\u003c4\u003e [515.287333] drm_dp_atomic_release_time_slots.cold+0x17/0x3d\n[drm_display_helper]\n\u003c4\u003e [515.287355] mst_connector_atomic_check+0x159/0x180 [xe]\n\u003c4\u003e [515.287546] drm_atomic_helper_check_modeset+0x4d9/0xfa0\n\u003c4\u003e [515.287550] ? __ww_mutex_lock.constprop.0+0x6f/0x1a60\n\u003c4\u003e [515.287562] intel_atomic_check+0x119/0x2b80 [xe]\n\u003c4\u003e [515.287740] ? find_held_lock+0x31/0x90\n\u003c4\u003e [515.287747] ? lock_release+0xce/0x2a0\n\u003c4\u003e [515.287754] drm_atomic_check_only+0x6a2/0xb40\n\u003c4\u003e [515.287758] ? drm_atomic_add_affected_connectors+0x12b/0x140\n\u003c4\u003e [515.287765] drm_atomic_commit+0x6e/0xf0\n\u003c4\u003e [515.287766] ? _pfx__drm_printfn_info+0x10/0x10\n\u003c4\u003e [515.287774] drm_client_modeset_commit_atomic+0x25c/0x2b0\n\u003c4\u003e [515.287794] drm_client_modeset_commit_locked+0x60/0x1b0\n\u003c4\u003e [515.287795] ? mutex_lock_nested+0x1b/0x30\n\u003c4\u003e [515.287801] drm_client_modeset_commit+0x26/0x50\n\u003c4\u003e [515.287804] __drm_fb_helper_restore_fbdev_mode_unlocked+0xdc/0x110\n\u003c4\u003e [515.287810] drm_fb_helper_hotplug_event+0x120/0x140\n\u003c4\u003e [515.287814] drm_fbdev_client_hotplug+0x28/0xd0\n\u003c4\u003e [515.287819] drm_client_hotplug+0x6c/0xf0\n\u003c4\u003e [515.287824] drm_client_dev_hotplug+0x9e/0xd0\n\u003c4\u003e [515.287829] drm_kms_helper_hotplug_event+0x1a/0x30\n\u003c4\u003e [515.287834] drm_dp_delayed_destroy_work+0x3df/0x410\n[drm_display_helper]\n\u003c4\u003e [515.287861] process_one_work+0x22b/0x6f0\n\u003c4\u003e [515.287874] worker_thread+0x1e8/0x3d0\n\u003c4\u003e [515.287879] ? __pfx_worker_thread+0x10/0x10\n\u003c4\u003e [515.287882] kthread+0x11c/0x250\n\u003c4\u003e [515.287886] ? __pfx_kthread+0x10/0x10\n\u003c4\u003e [515.287890] ret_from_fork+0x2d7/0x310\n\u003c4\u003e [515.287894] ? __pfx_kthread+0x10/0x10\n\u003c4\u003e [515.287897] ret_from_fork_asm+0x1a/0x30","modified":"2026-06-27T11:55:08.492504105Z","published":"2026-05-27T12:14:55.722Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/71xxx/CVE-2025-71305.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/342ccffd9f77fc29fe1c05fd145e4d842bd2feaa"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3f44cdb5371faf225af37d5caba8f21ec0572469"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4d2ccdea18b564e3f73e3e543854acea64e6277d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/95dbd525efce2a9e9e1c50ad15213de644c85ad0"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ac9a7c329a5610051fc476644c9b9145a5965ecb"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d6afc7539ce06dadfa5b4787b3cfe79b95d8f67a"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/71xxx/CVE-2025-71305.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-71305"},{"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":"4d07b0bc403403438d9cf88450506240c5faf92f"},{"fixed":"95dbd525efce2a9e9e1c50ad15213de644c85ad0"},{"fixed":"ac9a7c329a5610051fc476644c9b9145a5965ecb"},{"fixed":"3f44cdb5371faf225af37d5caba8f21ec0572469"},{"fixed":"4d2ccdea18b564e3f73e3e543854acea64e6277d"},{"fixed":"d6afc7539ce06dadfa5b4787b3cfe79b95d8f67a"},{"fixed":"342ccffd9f77fc29fe1c05fd145e4d842bd2feaa"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-71305.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.1.0"},{"fixed":"6.1.165"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.128"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.75"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.16"}]},{"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-2025-71305.json"}}],"schema_version":"1.7.5"}