From patchwork Mon Nov 7 14:45:00 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stanislaw Gruszka X-Patchwork-Id: 13034521 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 2F11CC433FE for ; Mon, 7 Nov 2022 14:48:17 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 0157A10E38E; Mon, 7 Nov 2022 14:48:16 +0000 (UTC) Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by gabe.freedesktop.org (Postfix) with ESMTPS id E06B810E38E for ; Mon, 7 Nov 2022 14:48:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1667832489; x=1699368489; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=Bp1rGCIEaarCufhZcInB4PWfoJtElnC+2OKzXD+uY40=; b=mmaxOAghXqsCPjUxW8U+7e+2avTemGUFVdIV/8mft6uK1lKFxJCNAIYd TLHSNkyhbfNivA2xWVvTa0EMNEwjXQMy1QI7/HnJQThTDeMvIufi561Mq GsYX8Q5ov4KA/2+P/KWIHIARsKiq9k7gl8BDDP4zd2ZHzrh+eq9zFeMo3 WEsP0ldFsWwfxOaBhBN6UM6uuFdlc74zi3XJgD0SBMnVBvRI09Mrh0jMR B7lHlDqLmlWhgSXNHJrRbZFXvAyECb5qzSSSeuhTwi4IgxYJOUKj0CmRD PRI/4TOXPIda7o02kcg4YwC6fLC/UrpgOeQ8LOJnoUIjqlXLgsVZHVEbC A==; X-IronPort-AV: E=McAfee;i="6500,9779,10524"; a="310426749" X-IronPort-AV: E=Sophos;i="5.96,145,1665471600"; d="scan'208";a="310426749" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Nov 2022 06:46:36 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10524"; a="613878847" X-IronPort-AV: E=Sophos;i="5.96,145,1665471600"; d="scan'208";a="613878847" Received: from joe-255.igk.intel.com (HELO localhost) ([172.22.229.67]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Nov 2022 06:46:34 -0800 From: Stanislaw Gruszka To: dri-devel@lists.freedesktop.org Subject: [PATCH RESEND] drm: fix crash in drm_minor_alloc_release Date: Mon, 7 Nov 2022 15:45:00 +0100 Message-Id: <20221107144500.3692212-1-stanislaw.gruszka@linux.intel.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 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: , Cc: Stanislaw Gruszka , Thomas Zimmermann , Jacek Lawrynowicz Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" If drm_sysfs_minor_alloc() fail in drm_minor_alloc() we can end up freeing invalid minor->kdev pointer and drm_minor_alloc_release() will crash like below: RIP: 0010:kobject_put+0x19/0x1c0 RSP: 0018:ffffbc7001637c38 EFLAGS: 00010282 RAX: ffffffffa8d6deb0 RBX: 00000000ffffffff RCX: ffff9cb5912d4540 RDX: ffffffffa9c45ec5 RSI: ffff9cb5902f2b68 RDI: fffffffffffffff4 RBP: fffffffffffffff4 R08: ffffffffa9c40dec R09: 0000000000000008 R10: ffffffffaa81f7d2 R11: 00000000aa81f7ca R12: ffff9cb5912d4540 R13: ffff9cb5912d4540 R14: dead000000000122 R15: dead000000000100 FS: 00007f56b06e6740(0000) GS:ffff9cb728b40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000030 CR3: 000000011285b004 CR4: 0000000000170ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff07f0 DR7: 0000000000000400 Call Trace: drm_minor_alloc_release+0x19/0x50 drm_managed_release+0xab/0x150 drm_dev_init+0x21f/0x2f0 __devm_drm_dev_alloc+0x3c/0xa0 ivpu_probe+0x59/0x797 [intel_vpu 127058409b05eb2f99dcdecd3330bee28d6b3e76] pci_device_probe+0xa4/0x160 really_probe+0x164/0x340 __driver_probe_device+0x10d/0x190 device_driver_attach+0x26/0x50 bind_store+0x9f/0x120 kernfs_fop_write_iter+0x12d/0x1c0 new_sync_write+0x106/0x180 vfs_write+0x216/0x2a0 ksys_write+0x65/0xe0 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae Fix this crash by checking minor->kdev when freeing. Signed-off-by: Stanislaw Gruszka --- drivers/gpu/drm/drm_drv.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index 8214a0b1ab7f..e3a1243dd2ae 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -102,7 +102,8 @@ static void drm_minor_alloc_release(struct drm_device *dev, void *data) WARN_ON(dev != minor->dev); - put_device(minor->kdev); + if (!IS_ERR(minor->kdev)) + put_device(minor->kdev); spin_lock_irqsave(&drm_minor_lock, flags); idr_remove(&drm_minors_idr, minor->index);