CVE-2025-37761

Published May 1, 2025

Last updated 8 days ago

Overview

Description
In the Linux kernel, the following vulnerability has been resolved: drm/xe: Fix an out-of-bounds shift when invalidating TLB When the size of the range invalidated is larger than rounddown_pow_of_two(ULONG_MAX), The function macro roundup_pow_of_two(length) will hit an out-of-bounds shift [1]. Use a full TLB invalidation for such cases. v2: - Use a define for the range size limit over which we use a full TLB invalidation. (Lucas) - Use a better calculation of the limit. [1]: [ 39.202421] ------------[ cut here ]------------ [ 39.202657] UBSAN: shift-out-of-bounds in ./include/linux/log2.h:57:13 [ 39.202673] shift exponent 64 is too large for 64-bit type 'long unsigned int' [ 39.202688] CPU: 8 UID: 0 PID: 3129 Comm: xe_exec_system_ Tainted: G U 6.14.0+ #10 [ 39.202690] Tainted: [U]=USER [ 39.202690] Hardware name: ASUS System Product Name/PRIME B560M-A AC, BIOS 2001 02/01/2023 [ 39.202691] Call Trace: [ 39.202692] <TASK> [ 39.202695] dump_stack_lvl+0x6e/0xa0 [ 39.202699] ubsan_epilogue+0x5/0x30 [ 39.202701] __ubsan_handle_shift_out_of_bounds.cold+0x61/0xe6 [ 39.202705] xe_gt_tlb_invalidation_range.cold+0x1d/0x3a [xe] [ 39.202800] ? find_held_lock+0x2b/0x80 [ 39.202803] ? mark_held_locks+0x40/0x70 [ 39.202806] xe_svm_invalidate+0x459/0x700 [xe] [ 39.202897] drm_gpusvm_notifier_invalidate+0x4d/0x70 [drm_gpusvm] [ 39.202900] __mmu_notifier_release+0x1f5/0x270 [ 39.202905] exit_mmap+0x40e/0x450 [ 39.202912] __mmput+0x45/0x110 [ 39.202914] exit_mm+0xc5/0x130 [ 39.202916] do_exit+0x21c/0x500 [ 39.202918] ? lockdep_hardirqs_on_prepare+0xdb/0x190 [ 39.202920] do_group_exit+0x36/0xa0 [ 39.202922] get_signal+0x8f8/0x900 [ 39.202926] arch_do_signal_or_restart+0x35/0x100 [ 39.202930] syscall_exit_to_user_mode+0x1fc/0x290 [ 39.202932] do_syscall_64+0xa1/0x180 [ 39.202934] ? do_user_addr_fault+0x59f/0x8a0 [ 39.202937] ? lock_release+0xd2/0x2a0 [ 39.202939] ? do_user_addr_fault+0x5a9/0x8a0 [ 39.202942] ? trace_hardirqs_off+0x4b/0xc0 [ 39.202944] ? clear_bhb_loop+0x25/0x80 [ 39.202946] ? clear_bhb_loop+0x25/0x80 [ 39.202947] ? clear_bhb_loop+0x25/0x80 [ 39.202950] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 39.202952] RIP: 0033:0x7fa945e543e1 [ 39.202961] Code: Unable to access opcode bytes at 0x7fa945e543b7. [ 39.202962] RSP: 002b:00007ffca8fb4170 EFLAGS: 00000293 [ 39.202963] RAX: 000000000000003d RBX: 0000000000000000 RCX: 00007fa945e543e3 [ 39.202964] RDX: 0000000000000000 RSI: 00007ffca8fb41ac RDI: 00000000ffffffff [ 39.202964] RBP: 00007ffca8fb4190 R08: 0000000000000000 R09: 00007fa945f600a0 [ 39.202965] R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 [ 39.202966] R13: 00007fa9460dd310 R14: 00007ffca8fb41ac R15: 0000000000000000 [ 39.202970] </TASK> [ 39.202970] ---[ end trace ]--- (cherry picked from commit b88f48f86500bc0b44b4f73ac66d500a40d320ad)
Source
416baaa9-dc9f-4396-8d5f-8c081fb06d67
NVD status
Modified
Products
linux_kernel

Risk scores

CVSS 3.1

Type
Primary
Base score
7.1
Impact score
5.2
Exploitability score
1.8
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Severity
HIGH

Weaknesses

nvd@nist.gov
CWE-125

Social media

Hype score
Not currently trending

Configurations

  1. In the Linux kernel, the following vulnerability has been resolved: cgroup: Avoid iteration of dying tasks with zero refcount The commit 260fbcb92bbea ("cgroup: Move dying_tasks cleanup from cgroup_task_release() to cgroup_task_free()") extended the lifetime of tasks on the dying_tasks list. The iterators have provision to go through dying_tasks because of dying threadgroup leaders or explicit CSS_TASK_ITER_WITH_DEAD, however, it was expected that such tasks can obtain a new reference (that is possible before cgroup_task_release()/put_task_struct_rcu_user()). The tasks after cgroup_task_release() and before cgroup_task_free() are subject to race when they may or may not have ->usage count > 0. The race window is between css_task_iter_next() invocations when css_set_lock is released and we may arrive at a new ->task_pos. The iterator should not attempt to resurrect tasks whose ->usage count dropped to zero. (When that happens, __put_task_struct_rcu_cb() is already imminent and the returned task_struct would could be used after free.) As for the fix, we cannot simply check the signal->live count of a task on the dying list because that won't distinguish regular zombies waiting to be reaped from RCU remnant tasks that are going to be free'd. Therefore add an extra check to rule out ->usage==0 tasks from any iteration. The repeat: loop in css_task_iter_advance() doesn't consider ->usage count, so add a new loop to css_task_iter_next() to skip de-used tasks on the dying_list. Rough illustration of the possible race R (reader of cgroup.procs) T (thread) L (group leader) --------------------------------- -------------------------------- -------------------------------- L exits, signal->live > 0 cgroup_task_dead(L) css_set_skip_task_iters() // skips only cset->tasks list_add_tail(&L->cg_list, &cset->dying_tasks) css_task_iter_next() take css_set_lock css_task_iter_advance() leader && signal->live != 0 => it->task_pos = &L->cg_list release css_set_lock T exits --signal->live == 0 cgroup_task_dead(T) // css_set_lock release_task(T) cgroup_task_release(T) release_task(L) // zap_leader cgroup_task_release(L) put_task_struct_rcu_user(L) ...RCU... put_task_struct(L) L->usage = 0 /* L still on dying_tasks */ ...RCU... __put_task_struct(L) css_task_iter_next() // another iteration take css_set_lock it->task_pos = &L->cg_list get_task_struct(L) => addition on 0 drop css_set_lock cgroup_task_free(L) css_set_skip_task_iters() // dying skip comes too late free_task(L) cgroup_procs_show() task_pid_vnr(L)•CVE-2026-98163