If user provides a large value (such as 0x80) for parameter prefetch_mem_region_instance in vm_bind ioctl, it will cause BIT(prefetch_region) overflow as below: " ------------[ cut here ]------------ UBSAN: shift-out-of-bounds in drivers/gpu/drm/xe/xe_vm.c:3414:7 shift exponent 128 is too large for 64-bit type 'long unsigned int' CPU: 8 UID: 0 PID: 53120 Comm: xe_exec_system_ Tainted: G W 6.18.0-rc1-lgci-xe-kernel+ #200 PREEMPT(voluntary) Tainted: [W]=WARN Hardware name: ASUS System Product Name/PRIME Z790-P WIFI, BIOS 0812 02/24/2023 Call Trace: <TASK> dump_stack_lvl+0xa0/0xc0 dump_stack+0x10/0x20 ubsan_epilogue+0x9/0x40 __ubsan_handle_shift_out_of_bounds+0x10e/0x170 ? mutex_unlock+0x12/0x20 xe_vm_bind_ioctl.cold+0x20/0x3c [xe] ... " Fix it by validating prefetch_region before the BIT() usage.
v2: Add Closes and Cc stable kernels. (Matt)
Reported-by: Koen Koning koen.koning@intel.com Reported-by: Peter Senna Tschudin peter.senna@linux.intel.com Fixes: dd08ebf6c352 ("drm/xe: Introduce a new DRM driver for Intel GPUs") Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/6478 Cc: stable@vger.kernel.org # v6.8+ Reviewed-by: Matthew Auld matthew.auld@intel.com Signed-off-by: Shuicheng Lin shuicheng.lin@intel.com Signed-off-by: Matthew Auld matthew.auld@intel.com Link: https://patch.msgid.link/20251112181005.2120521-2-shuicheng.lin@intel.com (cherry picked from commit 8f565bdd14eec5611cc041dba4650e42ccdf71d9) Signed-off-by: Lucas De Marchi lucas.demarchi@intel.com (cherry picked from commit d52dea485cd3c98cfeeb474cf66cf95df2ab142f) Signed-off-by: Shuicheng Lin shuicheng.lin@intel.com --- drivers/gpu/drm/xe/xe_vm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c index 30c32717a980..ed457243e907 100644 --- a/drivers/gpu/drm/xe/xe_vm.c +++ b/drivers/gpu/drm/xe/xe_vm.c @@ -3475,8 +3475,8 @@ static int vm_bind_ioctl_check_args(struct xe_device *xe, struct xe_vm *vm, op == DRM_XE_VM_BIND_OP_PREFETCH) || XE_IOCTL_DBG(xe, prefetch_region && op != DRM_XE_VM_BIND_OP_PREFETCH) || - XE_IOCTL_DBG(xe, !(BIT(prefetch_region) & - xe->info.mem_region_mask)) || + XE_IOCTL_DBG(xe, prefetch_region >= (sizeof(xe->info.mem_region_mask) * 8) || + !(BIT(prefetch_region) & xe->info.mem_region_mask)) || XE_IOCTL_DBG(xe, obj && op == DRM_XE_VM_BIND_OP_UNMAP)) { err = -EINVAL;