From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f199.google.com (mail-il1-f199.google.com [209.85.166.199]) (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 B7C2F19D06D for ; Thu, 25 Jul 2024 13:53:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721915621; cv=none; b=MQeFGF/6EwS17FLH1ECuFwvc0Y4R7zsZf1/6DF98OP4ox8ybJYRSysSqFJE/g8ZBN88JBWVuKF0k3e/7id7q6gMw4EfxYHlVu7cxUSjgQDqjuhYnhS6/NWWLf0XVSjeQkGhYHCv5YoAKGZ3sjhG/CuTAowQfgp3B1dn/gMC/nDo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721915621; c=relaxed/simple; bh=J97+8GDUyXu4RsMWTgGQJvhbjUN2hFSbpzDeLCK0hVk=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=swOn6RjOlih5kpPaJlLBLd71pkE/S2IbK6vWqbGpPzDAOtAooToMySD2ysiFlI4ux5dWxipB4J66xy7YqxmZDg0AYHWos+y9yM+nkcDynNYEw24ylKhnjMYdwZP8L8U2+uJDLsNTIEjfib8ktFRwJYIKkVFQzllEfyPbkFNiS7g= 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=209.85.166.199 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-f199.google.com with SMTP id e9e14a558f8ab-39673758efeso9376655ab.3 for ; Thu, 25 Jul 2024 06:53:39 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1721915619; x=1722520419; 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=IbSESdSfl8Zy6XV/J6M7oHTzF6wnNaXjH3/ukGJlvGU=; b=WHV2SOaD+DuILhx72LhotuRJkC/0NpjNIjYszBpx3+prKo1hMJKRE5jotk97G7sO9J /EIS1k2XHDy9mpP+//DDk+NPi8NZIIhlGMhF0rxG9aTrXDPUJCb0DKupXT4oWkdujRmW 4gK+TxqZpA+zl18fSANT2W1Ifb1SH3cWv/W/c7Qxt9jlIGMQ4qAIRIKcbww/EQfSLPmT YZgKFpjJC1FIt9ymXx5NETiCeAR4i1iZd1bjIqGtqSRzQzWa81Skvkk3Xne8PgRwpYOD PEIvBZ4AR/oQdjkCIxKo8H0fuQiwpRT8nSRbDk/eMqis5DNvqU4fC3M+2cvmJY/Et/pb +vZw== X-Gm-Message-State: AOJu0YwtE1AW5npec4rUDUXz/MQU6anVTilBCFn0cxtW44IUT2V7pqfg qvMhA+DG/wSSY4mqHlU6666725vRGnPq2ZolZxLv7HNpSWENzAOAKmM1JqESb6S1DpCa5dO/AJu Uy4GXG3vsbhfCcrt1KuhIc/ayfnnsl/HHT83ZoS0A9jvwE9L1kOMJW0Q= X-Google-Smtp-Source: AGHT+IGJ/McZXe1+PUdkkxLpBU0pznv01yqwJwQWXb0ulcsoUnCK3JeRn7UyNIuNOIPe6q/Xj67KAc55W3TVbhZTDhyj0NLcFMWF Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:1c85:b0:398:d1fe:9868 with SMTP id e9e14a558f8ab-39a23fcf0dcmr1378775ab.4.1721915618921; Thu, 25 Jul 2024 06:53:38 -0700 (PDT) Date: Thu, 25 Jul 2024 06:53:38 -0700 In-Reply-To: <0000000000005c7ccb061e032b9b@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000cca23f061e12b868@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..484eb5082604 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); - if (!gc_th) - return; + mutex_lock(&gct_mutex); + gc_th = sbi->gc_thread; + if (!gc_th || !virt_addr_valid(gc_th)) + goto unlock; + + sbi->gc_thread = NULL; 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)