From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f197.google.com (mail-il1-f197.google.com [209.85.166.197]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 124421993BA for ; Thu, 25 Jul 2024 13:19:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.197 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721913570; cv=none; b=YJMizjReVfRdheua3039OcajfiZW15OdT1FKKOOwVtQx2orO7uIB7xnF3GwyGydHNOa/IJITuCwO/5mhzhP2u0YUH9cKZ/WZQsiMj4eb0EArIDToGB2OwIbdIqQJmAI0MZ1182omBXmqMrTLQgdOgQML5IsVMe+Dj04gRbpqMzw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721913570; c=relaxed/simple; bh=IB/Db3LGGsMTycLDC3ShxtPYNt26Z8ZUqIMci7k567s=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=eHZiTdL28yL9oXSp75mpy7fZBvs/UKlYDvNbuH6SOOeW/oiE1qwzTAUjiekflBeEilXKwoX7lnSInXsNDcgvalaOzL7cln/1+o7YvHaeeImAU1Nx7CmpikVl4cnP/+V9AkTd7Td8Qs7EUuxYt30lIgzHFVVt8/WHlzPg8aBlodI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.166.197 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-il1-f197.google.com with SMTP id e9e14a558f8ab-39835205d20so9625625ab.0 for ; Thu, 25 Jul 2024 06:19:28 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1721913568; x=1722518368; h=to:from:subject:message-id:in-reply-to:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=NBhYlkD+ZUh2j5IqrXDeHriyOAhgczqx3wAJP3U3fHg=; b=kGW3qNSJfz5DgjfbH2/XT6wJQZodD1tjgSkciXC700fQ+5HdKPEfvVKRPAOV0lHcjq G2c/LsMKcYG4YdlHrG9WTtjWXBxIVrdnHlYbiEPZ0JFQu//rEXYPQ3qx6yAP8gcpAxWH aXlDH2AOsTwlqoHQ4ZSMT+aFmWJ8gm6CCAyxZsTjSYo521vtbItzSM1YbEwObGP0u2PB nyLsc0s26Bg/F5P+lhIiDv+NR2kq/2Y5iuFvQUi5CrFd8cKV1e4/Zq7OuXhRi6uZsp3R i3e+4sj8cqUCz5/im8KbetZFbY3COKbI/kTd1xy1u6gTKNVevELtZ14otjRQf41kgzCE 1Cdw== X-Gm-Message-State: AOJu0Yz96mxSX3bYbWMU98JxRX8Ysj3vRuBm7rPAZypddTmChmJulbom guCqNNVDOmV7BZwrYulOuJcD15mfLFt7BvsWqM02xUgHnH39OnqqQQu/NZQHusBX84JGj733Mmc HBZr/ESXiIFhDkprUhGjfz7J42PwB7qQIKG/+qfO7wZi5tMswBP+DIjI= X-Google-Smtp-Source: AGHT+IEGZcta27VJJDUrywfnG4MMhwN6s6U9oYZ+UbXOQmkHsU5HXhqwxwHtjP/+7B9+mdpIrfStbhAjcGT7/dvRWrTBVATJwNm9 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:1a08:b0:397:b509:6441 with SMTP id e9e14a558f8ab-39a23fa30e8mr1571395ab.2.1721913568191; Thu, 25 Jul 2024 06:19:28 -0700 (PDT) Date: Thu, 25 Jul 2024 06:19:28 -0700 In-Reply-To: <0000000000005c7ccb061e032b9b@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <00000000000090f4e6061e123ec6@google.com> Subject: Re: [syzbot] Re: [syzbot] [f2fs?] KASAN: null-ptr-deref Write in f2fs_stop_gc_thread From: syzbot To: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" For archival purposes, forwarding an incoming command email to linux-kernel@vger.kernel.org. *** Subject: Re: [syzbot] [f2fs?] KASAN: null-ptr-deref Write in f2fs_stop_gc_thread Author: lizhi.xu@windriver.com before thread stop and free gc_thread, set sbi->gc_thread to NULL, and add lock for reentry f2fs_stop_gc_thread. #syz test: upstream 2c9b3512402e diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c index 6066c6eecf41..ebaf6b6fc65c 100644 --- a/fs/f2fs/gc.c +++ b/fs/f2fs/gc.c @@ -203,14 +203,22 @@ int f2fs_start_gc_thread(struct f2fs_sb_info *sbi) void f2fs_stop_gc_thread(struct f2fs_sb_info *sbi) { - struct f2fs_gc_kthread *gc_th = sbi->gc_thread; + struct f2fs_gc_kthread *gc_th; + static DEFINE_MUTEX(gct_mutex); - if (!gc_th) - return; + mutex_lock(&gct_mutex); + gc_th = sbi->gc_thread; + printk("gc thread: %p, gc thread valid: %d, %s\n", gc_th, virt_addr_valid(gc_th), __func__); + if (!gc_th || !virt_addr_valid(gc_th)) + goto unlock; + + sbi->gc_thread = NULL; + printk("2gc thread: %p, %s\n", gc_th, __func__); kthread_stop(gc_th->f2fs_gc_task); wake_up_all(&gc_th->fggc_wq); kfree(gc_th); - sbi->gc_thread = NULL; +unlock: + mutex_unlock(&gct_mutex); } static int select_gc_type(struct f2fs_sb_info *sbi, int gc_type)