From nobody Sun Feb 8 05:35:24 2026 Received: from m16.mail.163.com (m16.mail.163.com [117.135.210.4]) (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 4DBCC381C4; Fri, 16 Jan 2026 05:02:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=117.135.210.4 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768539755; cv=none; b=Hm/VcQHnNz7LXX0flhn04NcseC5kGjappXIcdqq6Azq0uvUxxnHmNM+hv53eH0f/maDYv5zet6bqaItz0++w5uuMFvL6hjNaz1OxpgUWdphJYfq4P2jOjcTD66FSxfWV1YoD+glZTBbZvBgGj18lN55Xr3j6krf3TEXxpO18I/A= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768539755; c=relaxed/simple; bh=2lzUz9h1vua/H2JQTmqw5HA3FkojC1JTpQPO7x8oVY0=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version:Content-Type; b=Klk2/Cc1oVYS+x96n77QASt/+Zm5jTOa6OHDwF4Yvl2XNlgLRRnpaVuk2bqcvBaYwl/ltFHvImHg0szn9wlfiT5Uh40bV5M1Qi+WS4Wp6vLuR+9YqkDq72dq7713HEG53Wv6gDhEAvH0QZo+ONZ/nBvzCFJZHn88qoR8+XtKtI0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=QF84nhio; arc=none smtp.client-ip=117.135.210.4 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="QF84nhio" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:To:Subject:Date:Message-Id:MIME-Version: Content-Type; bh=xDzU4ApYApKN39wDu9fSahS1bVmty/puJiOGtVwxREg=; b=QF84nhiosDjCdPxB5bqnBCO4p9oyZSP+22awo7nFdzq4rliUzFsw4sbmC/Ah1l KUtC7M5YA6KuIjaayS7ZshIIgWLU3uboH8wc8PDz7AMQ5XRFIJRsO9afHKz4OiJz 8hSZvIAvZzuAwq7KLqE0dbgazXt1Jcslrb1mhs6U01zdk= Received: from pek-lpg-core6.wrs.com (unknown []) by gzga-smtp-mtada-g0-2 (Coremail) with SMTP id _____wAHb3NPxmlp82WtHA--.35186S2; Fri, 16 Jan 2026 13:02:08 +0800 (CST) From: Rahul Sharma To: gregkh@linuxfoundation.org, stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Gaosheng Cui , =?UTF-8?q?Christian=20K=C3=B6nig?= , Rahul Sharma Subject: [PATCH v5.15] drm/ttm: fix undefined behavior in bit shift for TTM_TT_FLAG_PRIV_POPULATED Date: Fri, 16 Jan 2026 13:02:05 +0800 Message-Id: <20260116050205.2296956-1-black.hawk@163.com> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: _____wAHb3NPxmlp82WtHA--.35186S2 X-Coremail-Antispam: 1Uf129KBjvJXoWxZr43tr43trW8ZF13uw13CFg_yoWrXFWrpa 15G343Ar45trs8uw4xXFy0ya4qyanrtF4DZrs5Ar1xZrs2yr129FWDKw13WFyUGrWUJryf XFnayr95Z3Wq9aDanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0pM0PfUUUUUU= X-CM-SenderInfo: 5eoduy4okd4yi6rwjhhfrp/xtbC+RJ6FGlpxlKV0wAA3X 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 K=C3=B6nig Link: https://patchwork.freedesktop.org/patch/msgid/20221031113350.4180975-= 1-cuigaosheng1@huawei.com Signed-off-by: Christian K=C3=B6nig [ 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 --- include/drm/ttm/ttm_tt.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/drm/ttm/ttm_tt.h b/include/drm/ttm/ttm_tt.h index b20e89d321b0..4c35802209c4 100644 --- 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) =20 -#define TTM_PAGE_FLAG_PRIV_POPULATED (1 << 31) +#define TTM_PAGE_FLAG_PRIV_POPULATED (1U << 31) =20 /** * struct ttm_tt --=20 2.34.1