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 X-Spam-Level: X-Spam-Status: No, score=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E521AC07E9C for ; Wed, 7 Jul 2021 09:34:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C79AC61C78 for ; Wed, 7 Jul 2021 09:34:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231259AbhGGJhD (ORCPT ); Wed, 7 Jul 2021 05:37:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59084 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230429AbhGGJhC (ORCPT ); Wed, 7 Jul 2021 05:37:02 -0400 Received: from mail-pl1-x630.google.com (mail-pl1-x630.google.com [IPv6:2607:f8b0:4864:20::630]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 19307C061574; Wed, 7 Jul 2021 02:34:22 -0700 (PDT) Received: by mail-pl1-x630.google.com with SMTP id u19so747151plc.3; Wed, 07 Jul 2021 02:34:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=7A9IWhxTcjxSny22G7AW0hGs7rwf2yW7az05u+6RoYE=; b=ToTv+B8uFC5YwEw4rtqyBh73Hl4yQ2yT1tBgzfI24mm/cDtiAqkhdm2XerNggyR2jg d4XAk624sjmg8oJUNa1UifWKEQzLL0w3xwvB+QTCpLiWSWfXj8AqFh+9G7CKgh+41Mvh nzNkNPwepYlbIUC/13GMMoMmdnd7KkCeXINGgFIOU1LcTtakXTPHzRGIkqxCKfq2Q0M7 di1HsUElog9DIolKPtiZ8sHGU0iluUbFwEvCl07ticDhXZK0iimkua5MNIA1Xz8tPFd1 1okP6/PNKkOkl7CZVPHjLgsv61i8hA2capKLLReIorm2Z1QfXZ48yRpMF0nlpKYO9Uty zWiw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=7A9IWhxTcjxSny22G7AW0hGs7rwf2yW7az05u+6RoYE=; b=tTRiQWRQce4xJImfLXG0AIGld49bBn+/nqfVF9l0KwNDFreshlYP7zXcwn+4MU4Jmu 4nEmYfjnzlPak7YDo62a6nT78iHHF46qj4MGesOHdCrmb0lhHR4WzdHtTtU0L26hnkTx yJqbIzNdf1VSyk9X6WlTmPIeiGjQZnyWz8nnV+6x6QQioJbVwMwBlK1N0rB4t8b2tNfc rpaCpw3oRv4od2DRExHikUWLS403QtIpApZV0FA3K3qvNpKrbS38OM5MDhWT/3MCRk4C 658R7QSYZrlj00dYHBkN+E6CpFJQdx+moLC5KVKZc/COLim6aD2QYP99Yj1uKIhEMdgk OOyQ== X-Gm-Message-State: AOAM5312vgdkaAm22Nyey9vDHROOy+61BiHpL+R7e4Bs4h16xQgiP/wS WlDmXwqUprwzhvStuqMuoIw= X-Google-Smtp-Source: ABdhPJxkVTYBuRA5pvDPRKa8MeTqNyrY+pxYn1h/pO+GE1+aPGoD+A6eV+VJ5LUY2Og76r8BEOWMcA== X-Received: by 2002:a17:90a:4cc4:: with SMTP id k62mr24979242pjh.64.1625650461554; Wed, 07 Jul 2021 02:34:21 -0700 (PDT) Received: from localhost.localdomain ([45.135.186.27]) by smtp.gmail.com with ESMTPSA id b65sm19126318pfa.32.2021.07.07.02.34.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 07 Jul 2021 02:34:21 -0700 (PDT) From: Dongliang Mu To: Mauro Carvalho Chehab , Igor Matheus Andrade Torrente , Hans Verkuil Cc: Dongliang Mu , Mauro Carvalho Chehab , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2] [media] em28xx-input: fix refcount bug in em28xx_usb_disconnect Date: Wed, 7 Jul 2021 17:34:09 +0800 Message-Id: <20210707093409.1445747-1-mudongliangabcd@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If em28xx_ir_init fails, it would decrease the refcount of dev. However, in the em28xx_ir_fini, when ir is NULL, it goes to ref_put and decrease the refcount of dev. This will lead to a refcount bug. Fix this bug by removing the kref_put in the error handling code of em28xx_ir_init. refcount_t: underflow; use-after-free. WARNING: CPU: 0 PID: 7 at lib/refcount.c:28 refcount_warn_saturate+0x18e/0x1a0 lib/refcount.c:28 Modules linked in: CPU: 0 PID: 7 Comm: kworker/0:1 Not tainted 5.13.0 #3 Workqueue: usb_hub_wq hub_event RIP: 0010:refcount_warn_saturate+0x18e/0x1a0 lib/refcount.c:28 Call Trace: kref_put.constprop.0+0x60/0x85 include/linux/kref.h:69 em28xx_usb_disconnect.cold+0xd7/0xdc drivers/media/usb/em28xx/em28xx-cards.c:4150 usb_unbind_interface+0xbf/0x3a0 drivers/usb/core/driver.c:458 __device_release_driver drivers/base/dd.c:1201 [inline] device_release_driver_internal+0x22a/0x230 drivers/base/dd.c:1232 bus_remove_device+0x108/0x160 drivers/base/bus.c:529 device_del+0x1fe/0x510 drivers/base/core.c:3540 usb_disable_device+0xd1/0x1d0 drivers/usb/core/message.c:1419 usb_disconnect+0x109/0x330 drivers/usb/core/hub.c:2221 hub_port_connect drivers/usb/core/hub.c:5151 [inline] hub_port_connect_change drivers/usb/core/hub.c:5440 [inline] port_event drivers/usb/core/hub.c:5586 [inline] hub_event+0xf81/0x1d40 drivers/usb/core/hub.c:5668 process_one_work+0x2c9/0x610 kernel/workqueue.c:2276 process_scheduled_works kernel/workqueue.c:2338 [inline] worker_thread+0x333/0x5b0 kernel/workqueue.c:2424 kthread+0x188/0x1d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Reported-by: Dongliang Mu Fixes: ac5688637144 ("media: em28xx: Fix possible memory leak of em28xx struct") Signed-off-by: Dongliang Mu --- v1->v2: move kref_get to the original position drivers/media/usb/em28xx/em28xx-input.c | 1 - 1 file changed, 1 deletion(-) diff --git a/drivers/media/usb/em28xx/em28xx-input.c b/drivers/media/usb/em28xx/em28xx-input.c index 59529cbf9cd0..0b6d77c3bec8 100644 --- a/drivers/media/usb/em28xx/em28xx-input.c +++ b/drivers/media/usb/em28xx/em28xx-input.c @@ -842,7 +842,6 @@ static int em28xx_ir_init(struct em28xx *dev) kfree(ir); ref_put: em28xx_shutdown_buttons(dev); - kref_put(&dev->ref, em28xx_free_device); return err; } -- 2.25.1