This is a note to let you know that I've just added the patch titled drm/ttm: fix undefined behavior in bit shift for TTM_TT_FLAG_PRIV_POPULATED to the 6.0-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-ttm-fix-undefined-behavior-in-bit-shift-for-ttm_.patch and it can be found in the queue-6.0 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 11c1e96661a8e54360fe0574584b332e057fae62 Author: Gaosheng Cui <cuigaosheng1@xxxxxxxxxx> Date: Mon Oct 31 19:33:50 2022 +0800 drm/ttm: fix undefined behavior in bit shift for TTM_TT_FLAG_PRIV_POPULATED [ Upstream commit 387659939c00156f8d6bab0fbc55b4eaf2b6bc5b ] 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: 3312be8f6fc8 ("drm/ttm: move populated state into page flags") Signed-off-by: Gaosheng Cui <cuigaosheng1@xxxxxxxxxx> Reviewed-by: Christian König <christian.koenig@xxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20221031113350.4180975-1-cuigaosheng1@xxxxxxxxxx Signed-off-by: Christian König <christian.koenig@xxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/include/drm/ttm/ttm_tt.h b/include/drm/ttm/ttm_tt.h index 17a0310e8aaa..b7d3f3843f1e 100644 --- a/include/drm/ttm/ttm_tt.h +++ b/include/drm/ttm/ttm_tt.h @@ -88,7 +88,7 @@ struct ttm_tt { #define TTM_TT_FLAG_EXTERNAL (1 << 2) #define TTM_TT_FLAG_EXTERNAL_MAPPABLE (1 << 3) -#define TTM_TT_FLAG_PRIV_POPULATED (1 << 31) +#define TTM_TT_FLAG_PRIV_POPULATED (1U << 31) uint32_t page_flags; /** @num_pages: Number of pages in the page array. */ uint32_t num_pages;