From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f200.google.com (mail-il1-f200.google.com [209.85.166.200]) (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 E49FA249ED for ; Thu, 25 Jul 2024 08:08:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.200 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721894916; cv=none; b=Ch7wJFB1lU/VEmXowBgbg3u/hhBDJ4WrODsuLf2rNz2AjD3jAg4aEzs1EuIPzwtnJ8gec1ie9UMg7WSDnM3V9jTAbT4eEdwq33lfYIgLNWv3CAbmw1/dg0Pok/aZlDHU/z0eJMsMrOvks0ECrnHezUgN1ffS47zutAn8K72qQDc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721894916; c=relaxed/simple; bh=XeiUxrwhAvAusskCNoQclL4KC913p10E6GDjwUOn694=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=SpGFcsF5gAJFV/e9l+CGQn+52s43/3CffrRs0wHYfK/J2QZJWaMpSyM3P024Zln7YneDoksGiJBLVSUd6eVbTkjSgfWzqe+UtkknoiQjZ1XqruqnlwE693sm5cQ/uyiayU9XDNPeCiBEfTLXep52iu86mteXDlPKzxVHTIhaXAc= 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=209.85.166.200 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-f200.google.com with SMTP id e9e14a558f8ab-39835205d20so5560915ab.0 for ; Thu, 25 Jul 2024 01:08:34 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1721894914; x=1722499714; 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=itgpCFpt5Q9ovIgvk7WE03fAJaHAFu1VC7zt5Xy8+5A=; b=tm6jkLtDl8xA1r6D/Y+JrLxEHGA4L66mWqbdC0twn62qfDC76CGhzQQdW8xlMJ1WDv fRQCueCCe8j6tvqZvBjmRZ/GfPk18C0TM3tu4UhXO6/+97u4F7IPJ5r0VMoMxWShWnk1 nccp8xrE7IjxFmPrktnzK9n61seVwWG/hswudAdo/70K9tp53yuWfGWQjeRYJgdZU2mK yocRCZoLirGYpKhzENBdemWhxv/5/5QnD+kTOd9RCO3ZE2zu5972sAF/Sj3MVXzcX810 54o7mPLoT/jK0VnjM7Z+ZOdaoaNEDp8lO1aWk7EzrPp2XMYyylvivYNM/cx4mHCiRReI BS5A== X-Gm-Message-State: AOJu0YzXRjYAvs6ig09D88fFFRKDGMcCl1FOpzsNfP5XnvMbefeFvkR0 fhhk78SfEbP94qxY43HYTynxFzzefFPtulhPKcq/2k4Sw1nA4Eea96bOh96QdGOLSLcdMRN6upw hnU+WKPGfmWhefPRzXVaTGXPCEEjTHqb6nQgahy9TzCfjgza9pC4pTrs= X-Google-Smtp-Source: AGHT+IFfw1x/2nBbbZukZF63h1Sg2+kpreGE8Hd/Zp0WrqWSwBFBeVXM+2RoSmc5PAmkTxWjKWKLdEXloaeoN4rpD1WV/FIZ4jtq Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:2196:b0:397:7dd7:bea5 with SMTP id e9e14a558f8ab-39a23d159femr1161785ab.0.1721894914045; Thu, 25 Jul 2024 01:08:34 -0700 (PDT) Date: Thu, 25 Jul 2024 01:08:34 -0700 In-Reply-To: <0000000000005c7ccb061e032b9b@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000b14c3e061e0de63d@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..228cad05b32b 100644 --- a/fs/f2fs/gc.c +++ b/fs/f2fs/gc.c @@ -203,14 +203,20 @@ 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); + mutex_lock(&gct_mutex); + gc_th = sbi->gc_thread; if (!gc_th) - return; + goto unlock; + kthread_stop(gc_th->f2fs_gc_task); wake_up_all(&gc_th->fggc_wq); - kfree(gc_th); sbi->gc_thread = NULL; + kfree(gc_th); +unlock: + mutex_unlock(&gct_mutex); } static int select_gc_type(struct f2fs_sb_info *sbi, int gc_type)