From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 22077CCD187 for ; Tue, 14 Oct 2025 04:57:16 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 657D810E52E; Tue, 14 Oct 2025 04:57:14 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (1024-bit key; unprotected) header.d=rong.moe header.i=i@rong.moe header.b="p1SWyS1t"; dkim-atps=neutral Received: from sender4-op-o15.zoho.com (sender4-op-o15.zoho.com [136.143.188.15]) by gabe.freedesktop.org (Postfix) with ESMTPS id 7363210E190; Mon, 13 Oct 2025 16:47:55 +0000 (UTC) ARC-Seal: i=1; a=rsa-sha256; t=1760374071; cv=none; d=zohomail.com; s=zohoarc; b=CcSvilBHdOmvFLGUeUyw2QLYn3G0RaJrwCaFRfp6vPZZ938nNva1t/ta87MWRrbO4fqeut2EkrmrrJyuE+++TNc/PN3cO5RcBSf0V6jbmJTkagKq735iYz/zPZnMnWhSJSCXmy3+5U71RFZC7BUD65ns59imFr0kE8BwoHROVHk= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1760374071; h=Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:MIME-Version:Message-ID:Subject:Subject:To:To:Message-Id:Reply-To; bh=TOda1Z7snsIxBjSh27hmk/EzkMek96gsqlQJrQUA3Xs=; b=ehDNHq7pBuHZIkhUALDvXwG0l5irSAbnnNwqzDyxdQID6wN2eSd7xIuupYwMAq58xmecd/YNKqgP5L/pDfn9L5EPSERe3qYGl8yonbAkeb0XhmLQVdZwEvMw2NGaXSTcR/XqevmVmyehDQbEPXGg+PAo4BdG5gs1pHO5XSookQU= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=rong.moe; spf=pass smtp.mailfrom=i@rong.moe; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1760374071; s=zmail; d=rong.moe; i=i@rong.moe; h=From:From:To:To:Cc:Cc:Subject:Subject:Date:Date:Message-ID:MIME-Version:Content-Transfer-Encoding:Message-Id:Reply-To; bh=TOda1Z7snsIxBjSh27hmk/EzkMek96gsqlQJrQUA3Xs=; b=p1SWyS1t745pjsHRmNZ+K8zyrrD+RrFLlUn4nfcl2WdPT7OPlXa5lO5auXA7/NDR TxeRxk6H2Yb9weORUekS3xrrgk3uohDRld5sgU0PR7H06kX+GDQNZEWprPG0SBx4uKp +Z9WIS8bL+GXHW5+pb9j5XNXbLwnoqdv3TCT0GWc= Received: by mx.zohomail.com with SMTPS id 1760374068043429.87704175723024; Mon, 13 Oct 2025 09:47:48 -0700 (PDT) From: Rong Zhang To: Harry Wentland , Leo Li , Rodrigo Siqueira , Alex Deucher , =?UTF-8?q?Christian=20K=C3=B6nig?= , David Airlie , Simona Vetter Cc: Rong Zhang , Wenjing Liu , Hamza Mahfooz , Aurabindo Pillai , amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH] drm/amd/display: Fix NULL deref in debugfs odm_combine_segments Date: Tue, 14 Oct 2025 00:47:35 +0800 Message-ID: <20251013164742.24660-1-i@rong.moe> X-Mailer: git-send-email 2.51.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-ZohoMailClient: External X-Mailman-Approved-At: Tue, 14 Oct 2025 04:57:11 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" When a connector is connected but inactive (e.g., disabled by desktop environments), pipe_ctx->stream_res.tg will be destroyed. Then, reading odm_combine_segments causes kernel NULL pointer dereference. BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] SMP NOPTI CPU: 16 UID: 0 PID: 26474 Comm: cat Not tainted 6.17.0+ #2 PREEMPT(lazy) e6a17af9ee6db7c63e9d90dbe5b28ccab67520c6 Hardware name: LENOVO 21Q4/LNVNB161216, BIOS PXCN25WW 03/27/2025 RIP: 0010:odm_combine_segments_show+0x93/0xf0 [amdgpu] Code: 41 83 b8 b0 00 00 00 01 75 6e 48 98 ba a1 ff ff ff 48 c1 e0 0c 48 8d 8c 07 d8 02 00 00 48 85 c9 74 2d 48 8b bc 07 f0 08 00 00 <48> 8b 07 48 8b 80 08 02 00> RSP: 0018:ffffd1bf4b953c58 EFLAGS: 00010286 RAX: 0000000000005000 RBX: ffff8e35976b02d0 RCX: ffff8e3aeed052d8 RDX: 00000000ffffffa1 RSI: ffff8e35a3120800 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffff8e3580eb0000 R09: ffff8e35976b02d0 R10: ffffd1bf4b953c78 R11: 0000000000000000 R12: ffffd1bf4b953d08 R13: 0000000000040000 R14: 0000000000000001 R15: 0000000000000001 FS: 00007f44d3f9f740(0000) GS:ffff8e3caa47f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000006485c2000 CR4: 0000000000f50ef0 PKRU: 55555554 Call Trace: seq_read_iter+0x125/0x490 ? __alloc_frozen_pages_noprof+0x18f/0x350 seq_read+0x12c/0x170 full_proxy_read+0x51/0x80 vfs_read+0xbc/0x390 ? __handle_mm_fault+0xa46/0xef0 ? do_syscall_64+0x71/0x900 ksys_read+0x73/0xf0 do_syscall_64+0x71/0x900 ? count_memcg_events+0xc2/0x190 ? handle_mm_fault+0x1d7/0x2d0 ? do_user_addr_fault+0x21a/0x690 ? exc_page_fault+0x7e/0x1a0 entry_SYSCALL_64_after_hwframe+0x6c/0x74 RIP: 0033:0x7f44d4031687 Code: 48 89 fa 4c 89 df e8 58 b3 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00> RSP: 002b:00007ffdb4b5f0b0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007f44d3f9f740 RCX: 00007f44d4031687 RDX: 0000000000040000 RSI: 00007f44d3f5e000 RDI: 0000000000000003 RBP: 0000000000040000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00007f44d3f5e000 R13: 0000000000000003 R14: 0000000000000000 R15: 0000000000040000 Modules linked in: tls tcp_diag inet_diag xt_mark ccm snd_hrtimer snd_seq_dummy snd_seq_midi snd_seq_oss snd_seq_midi_event snd_rawmidi snd_seq snd_seq_device x> snd_hda_codec_atihdmi snd_hda_codec_realtek_lib lenovo_wmi_helpers think_lmi snd_hda_codec_generic snd_hda_codec_hdmi snd_soc_core kvm snd_compress uvcvideo sn> platform_profile joydev amd_pmc mousedev mac_hid sch_fq_codel uinput i2c_dev parport_pc ppdev lp parport nvme_fabrics loop nfnetlink ip_tables x_tables dm_cryp> CR2: 0000000000000000 ---[ end trace 0000000000000000 ]--- RIP: 0010:odm_combine_segments_show+0x93/0xf0 [amdgpu] Code: 41 83 b8 b0 00 00 00 01 75 6e 48 98 ba a1 ff ff ff 48 c1 e0 0c 48 8d 8c 07 d8 02 00 00 48 85 c9 74 2d 48 8b bc 07 f0 08 00 00 <48> 8b 07 48 8b 80 08 02 00> RSP: 0018:ffffd1bf4b953c58 EFLAGS: 00010286 RAX: 0000000000005000 RBX: ffff8e35976b02d0 RCX: ffff8e3aeed052d8 RDX: 00000000ffffffa1 RSI: ffff8e35a3120800 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffff8e3580eb0000 R09: ffff8e35976b02d0 R10: ffffd1bf4b953c78 R11: 0000000000000000 R12: ffffd1bf4b953d08 R13: 0000000000040000 R14: 0000000000000001 R15: 0000000000000001 FS: 00007f44d3f9f740(0000) GS:ffff8e3caa47f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000006485c2000 CR4: 0000000000f50ef0 PKRU: 55555554 Fix this by checking pipe_ctx->stream_res.tg before dereferencing. Fixes: 07926ba8a44f ("drm/amd/display: Add debugfs interface for ODM combine info") Cc: stable@vger.kernel.org Signed-off-by: Rong Zhang --- drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c index f263e1a4537e1..00dac862b665a 100644 --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_debugfs.c @@ -1302,7 +1302,8 @@ static int odm_combine_segments_show(struct seq_file *m, void *unused) if (connector->status != connector_status_connected) return -ENODEV; - if (pipe_ctx != NULL && pipe_ctx->stream_res.tg->funcs->get_odm_combine_segments) + if (pipe_ctx && pipe_ctx->stream_res.tg && + pipe_ctx->stream_res.tg->funcs->get_odm_combine_segments) pipe_ctx->stream_res.tg->funcs->get_odm_combine_segments(pipe_ctx->stream_res.tg, &segments); seq_printf(m, "%d\n", segments); base-commit: 3a8660878839faadb4f1a6dd72c3179c1df56787 -- 2.51.0