From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6579B2BEFED; Wed, 4 Feb 2026 15:01:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770217272; cv=none; b=O3wowQp5rLpnY+CM8v4BcFwey4QhDw4khuWSrTH8Vxag9L7PoKZwjWC7SOnLXb3Z41KzdaPxDc+WbAMjGmW/+VJgKRX3PrZ/BHzP2Epa2QGfUc3Saih8iLql4N6js1fCBak7/PiZWpenNMs1kniJubyUgg5daYmIB3W1o6zLuQs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770217272; c=relaxed/simple; bh=chxGI0Wj+tr9zJIxzjXbY2Dsafi0QQE4zqEhCWXiLmI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Yqw41VDY2m7c3i6yvxA7IMvIbLjPsL/yESA2OhySqzQ3WgV3SK0TTuRKCRXQfY9hesAlGwF9cuJespePLeKOIK9UJO32i3o3hjcRjLKnEgOeSH/kqyRqcwmBqaTo0Jq3pryuJfdtRVo4P9opZAKVjG1iEeswE9jtl2fq45W85nY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=JTRxUVfp; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="JTRxUVfp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 56DF9C2BC86; Wed, 4 Feb 2026 15:01:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1770217272; bh=chxGI0Wj+tr9zJIxzjXbY2Dsafi0QQE4zqEhCWXiLmI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JTRxUVfprZtmax2VEUMQ/8w2rS0MqIwaxMo3BoJQMETizQKixSN0UAhlQJHLvVYSs WsFZcwolJ1cfkE5WyhS+bhBnMTY+bLUzC3KG5H26sNTbufDk0omrjgHsb3T7hiBCHt lDBjOy544Y+T+Vs1D1J71mNQAdSgxEwSHVr1ov9k= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Gaosheng Cui , =?UTF-8?q?Christian=20K=C3=B6nig?= , Rahul Sharma Subject: [PATCH 5.15 175/206] drm/ttm: fix undefined behavior in bit shift for TTM_TT_FLAG_PRIV_POPULATED Date: Wed, 4 Feb 2026 15:40:06 +0100 Message-ID: <20260204143904.515368980@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260204143858.193781818@linuxfoundation.org> References: <20260204143858.193781818@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Gaosheng Cui [ Upstream 387659939c00156f8d6bab0fbc55b4eaf2b6bc5b commit ] 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: 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 Fixes: 3312be8f6fc8 ("drm/ttm: move populated state into page flags") Signed-off-by: Gaosheng Cui Reviewed-by: Christian König Link: https://patchwork.freedesktop.org/patch/msgid/20221031113350.4180975-1-cuigaosheng1@huawei.com Signed-off-by: Christian König [ The context change is due to the commit 43d46f0b78bb ("drm/ttm: s/FLAG_SG/FLAG_EXTERNAL/") in v5.16 which is irrelevant to the logic of this patch. In addition, v6.1 has included the fix. ] Signed-off-by: Rahul Sharma Signed-off-by: Greg Kroah-Hartman --- include/drm/ttm/ttm_tt.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/include/drm/ttm/ttm_tt.h +++ b/include/drm/ttm/ttm_tt.h @@ -43,7 +43,7 @@ struct ttm_operation_ctx; #define TTM_PAGE_FLAG_SG (1 << 8) #define TTM_PAGE_FLAG_NO_RETRY (1 << 9) -#define TTM_PAGE_FLAG_PRIV_POPULATED (1 << 31) +#define TTM_PAGE_FLAG_PRIV_POPULATED (1U << 31) /** * struct ttm_tt