• Gaosheng Cui's avatar
    drm/ttm: fix undefined behavior in bit shift for TTM_TT_FLAG_PRIV_POPULATED · 38765993
    Gaosheng Cui authored
    Shifting signed 32-bit value by 31 bits is undefined, so changing
    significant bit to unsigned. The UBSAN warning calltrace like below:
    
    UBSAN: shift-out-of-bounds in ./include/drm/ttm/ttm_tt.h:122:26
    left shift of 1 by 31 places cannot be represented in type 'int'
    Call Trace:
     <TASK>
     dump_stack_lvl+0x7d/0xa5
     dump_stack+0x15/0x1b
     ubsan_epilogue+0xe/0x4e
     __ubsan_handle_shift_out_of_bounds+0x1e7/0x20c
     ttm_bo_move_memcpy+0x3b4/0x460 [ttm]
     bo_driver_move+0x32/0x40 [drm_vram_helper]
     ttm_bo_handle_move_mem+0x118/0x200 [ttm]
     ttm_bo_validate+0xfa/0x220 [ttm]
     drm_gem_vram_pin_locked+0x70/0x1b0 [drm_vram_helper]
     drm_gem_vram_pin+0x48/0xb0 [drm_vram_helper]
     drm_gem_vram_plane_helper_prepare_fb+0x53/0xe0 [drm_vram_helper]
     drm_gem_vram_simple_display_pipe_prepare_fb+0x26/0x30 [drm_vram_helper]
     drm_simple_kms_plane_prepare_fb+0x4d/0xe0 [drm_kms_helper]
     drm_atomic_helper_prepare_planes+0xda/0x210 [drm_kms_helper]
     drm_atomic_helper_commit+0xc3/0x1e0 [drm_kms_helper]
     drm_atomic_commit+0x9c/0x160 [drm]
     drm_client_modeset_commit_atomic+0x33a/0x380 [drm]
     drm_client_modeset_commit_locked+0x77/0x220 [drm]
     drm_client_modeset_commit+0x31/0x60 [drm]
     __drm_fb_helper_restore_fbdev_mode_unlocked+0xa7/0x170 [drm_kms_helper]
     drm_fb_helper_set_par+0x51/0x90 [drm_kms_helper]
     fbcon_init+0x316/0x790
     visual_init+0x113/0x1d0
     do_bind_con_driver+0x2a3/0x5c0
     do_take_over_console+0xa9/0x270
     do_fbcon_takeover+0xa1/0x170
     do_fb_registered+0x2a8/0x340
     fbcon_fb_registered+0x47/0xe0
     register_framebuffer+0x294/0x4a0
     __drm_fb_helper_initial_config_and_unlock+0x43c/0x880 [drm_kms_helper]
     drm_fb_helper_initial_config+0x52/0x80 [drm_kms_helper]
     drm_fbdev_client_hotplug+0x156/0x1b0 [drm_kms_helper]
     drm_fbdev_generic_setup+0xfc/0x290 [drm_kms_helper]
     bochs_pci_probe+0x6ca/0x772 [bochs]
     local_pci_probe+0x4d/0xb0
     pci_device_probe+0x119/0x320
     really_probe+0x181/0x550
     __driver_probe_device+0xc6/0x220
     driver_probe_device+0x32/0x100
     __driver_attach+0x195/0x200
     bus_for_each_dev+0xbb/0x120
     driver_attach+0x27/0x30
     bus_add_driver+0x22e/0x2f0
     driver_register+0xa9/0x190
     __pci_register_driver+0x90/0xa0
     bochs_pci_driver_init+0x52/0x1000 [bochs]
     do_one_initcall+0x76/0x430
     do_init_module+0x61/0x28a
     load_module+0x1f82/0x2e50
     __do_sys_finit_module+0xf8/0x190
     __x64_sys_finit_module+0x23/0x30
     do_syscall_64+0x58/0x80
     entry_SYSCALL_64_after_hwframe+0x63/0xcd
     </TASK>
    
    Fixes: 3312be8f ("drm/ttm: move populated state into page flags")
    Signed-off-by: default avatarGaosheng Cui <cuigaosheng1@huawei.com>
    Reviewed-by: default avatarChristian König <christian.koenig@amd.com>
    Link: https://patchwork.freedesktop.org/patch/msgid/20221031113350.4180975-1-cuigaosheng1@huawei.comSigned-off-by: default avatarChristian König <christian.koenig@amd.com>
    38765993
ttm_tt.h 7.81 KB