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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 46363C2D0DB for ; Thu, 23 Jan 2020 14:49:37 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id F236E2073A for ; Thu, 23 Jan 2020 14:49:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="X8/yAhuf" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F236E2073A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:58408 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iudnb-0008Qt-89 for qemu-devel@archiver.kernel.org; Thu, 23 Jan 2020 09:49:35 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:41911) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iubAu-0004N2-2E for qemu-devel@nongnu.org; Thu, 23 Jan 2020 07:01:30 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iubAr-0006nu-OA for qemu-devel@nongnu.org; Thu, 23 Jan 2020 07:01:28 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:27823 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iubAr-0006nU-Jn for qemu-devel@nongnu.org; Thu, 23 Jan 2020 07:01:25 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1579780885; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=pfYejLp3p2IfBeM0FrCsJccHwHgdomwifKJrQcOxA08=; b=X8/yAhufl4bt9MBwxZw9wDryge/PC643CDNiO+r/QZ/ucYlgeUKvadodzQadG9VbGOJ8Bh kjDo+DuxOalMm9hJri6BjdAzIHMdaalFbXF8gzCqfwmS5Ml3LnBmOvouyqnlvcxDByRNdg 5dXwX9jxUmoxPiD/xo57siiYRDyN4FI= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-29-ZL91oFtWOtK8YOF6g7-sbA-1; Thu, 23 Jan 2020 07:01:05 -0500 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 888E6100550E for ; Thu, 23 Jan 2020 12:01:04 +0000 (UTC) Received: from dgilbert-t580.localhost (unknown [10.36.118.0]) by smtp.corp.redhat.com (Postfix) with ESMTP id C30CE85754; Thu, 23 Jan 2020 12:01:03 +0000 (UTC) From: "Dr. David Alan Gilbert (git)" To: qemu-devel@nongnu.org, stefanha@redhat.com Subject: [PULL 096/111] virtiofsd: introduce inode refcount to prevent use-after-free Date: Thu, 23 Jan 2020 11:58:26 +0000 Message-Id: <20200123115841.138849-97-dgilbert@redhat.com> In-Reply-To: <20200123115841.138849-1-dgilbert@redhat.com> References: <20200123115841.138849-1-dgilbert@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-MC-Unique: ZL91oFtWOtK8YOF6g7-sbA-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 207.211.31.120 X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Stefan Hajnoczi If thread A is using an inode it must not be deleted by thread B when processing a FUSE_FORGET request. The FUSE protocol itself already has a counter called nlookup that is used in FUSE_FORGET messages. We cannot trust this counter since the untrusted client can manipulate it via FUSE_FORGET messages. Introduce a new refcount to keep inodes alive for the required lifespan. lo_inode_put() must be called to release a reference. FUSE's nlookup counter holds exactly one reference so that the inode stays alive as long as the client still wants to remember it. Note that the lo_inode->is_symlink field is moved to avoid creating a hole in the struct due to struct field alignment. Signed-off-by: Stefan Hajnoczi Reviewed-by: Misono Tomohiro Reviewed-by: Sergio Lopez Signed-off-by: Dr. David Alan Gilbert --- tools/virtiofsd/passthrough_ll.c | 169 ++++++++++++++++++++++++++----- 1 file changed, 146 insertions(+), 23 deletions(-) diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough= _ll.c index e3a6d6b611..ab1613586e 100644 --- a/tools/virtiofsd/passthrough_ll.c +++ b/tools/virtiofsd/passthrough_ll.c @@ -97,7 +97,13 @@ struct lo_key { =20 struct lo_inode { int fd; - bool is_symlink; + + /* + * Atomic reference count for this object. The nlookup field holds a + * reference and release it when nlookup reaches 0. + */ + gint refcount; + struct lo_key key; =20 /* @@ -116,6 +122,8 @@ struct lo_inode { fuse_ino_t fuse_ino; pthread_mutex_t plock_mutex; GHashTable *posix_locks; /* protected by lo_inode->plock_mutex */ + + bool is_symlink; }; =20 struct lo_cred { @@ -471,6 +479,23 @@ static ssize_t lo_add_inode_mapping(fuse_req_t req, st= ruct lo_inode *inode) return elem - lo_data(req)->ino_map.elems; } =20 +static void lo_inode_put(struct lo_data *lo, struct lo_inode **inodep) +{ + struct lo_inode *inode =3D *inodep; + + if (!inode) { + return; + } + + *inodep =3D NULL; + + if (g_atomic_int_dec_and_test(&inode->refcount)) { + close(inode->fd); + free(inode); + } +} + +/* Caller must release refcount using lo_inode_put() */ static struct lo_inode *lo_inode(fuse_req_t req, fuse_ino_t ino) { struct lo_data *lo =3D lo_data(req); @@ -478,6 +503,9 @@ static struct lo_inode *lo_inode(fuse_req_t req, fuse_i= no_t ino) =20 pthread_mutex_lock(&lo->mutex); elem =3D lo_map_get(&lo->ino_map, ino); + if (elem) { + g_atomic_int_inc(&elem->inode->refcount); + } pthread_mutex_unlock(&lo->mutex); =20 if (!elem) { @@ -487,10 +515,23 @@ static struct lo_inode *lo_inode(fuse_req_t req, fuse= _ino_t ino) return elem->inode; } =20 +/* + * TODO Remove this helper and force callers to hold an inode refcount unt= il + * they are done with the fd. This will be done in a later patch to make + * review easier. + */ static int lo_fd(fuse_req_t req, fuse_ino_t ino) { struct lo_inode *inode =3D lo_inode(req, ino); - return inode ? inode->fd : -1; + int fd; + + if (!inode) { + return -1; + } + + fd =3D inode->fd; + lo_inode_put(lo_data(req), &inode); + return fd; } =20 static void lo_init(void *userdata, struct fuse_conn_info *conn) @@ -545,6 +586,10 @@ static void lo_getattr(fuse_req_t req, fuse_ino_t ino, fuse_reply_attr(req, &buf, lo->timeout); } =20 +/* + * Increments parent->nlookup and caller must release refcount using + * lo_inode_put(&parent). + */ static int lo_parent_and_name(struct lo_data *lo, struct lo_inode *inode, char path[PATH_MAX], struct lo_inode **paren= t) { @@ -582,6 +627,7 @@ retry: p =3D &lo->root; pthread_mutex_lock(&lo->mutex); p->nlookup++; + g_atomic_int_inc(&p->refcount); pthread_mutex_unlock(&lo->mutex); } else { *last =3D '\0'; @@ -625,6 +671,7 @@ retry: =20 fail_unref: unref_inode_lolocked(lo, p, 1); + lo_inode_put(lo, &p); fail: if (retries) { retries--; @@ -663,6 +710,7 @@ fallback: if (res !=3D -1) { res =3D utimensat(parent->fd, path, tv, AT_SYMLINK_NOFOLLOW); unref_inode_lolocked(lo, parent, 1); + lo_inode_put(lo, &parent); } =20 return res; @@ -780,11 +828,13 @@ static void lo_setattr(fuse_req_t req, fuse_ino_t ino= , struct stat *attr, goto out_err; } } + lo_inode_put(lo, &inode); =20 return lo_getattr(req, ino, fi); =20 out_err: saverr =3D errno; + lo_inode_put(lo, &inode); fuse_reply_err(req, saverr); } =20 @@ -801,6 +851,7 @@ static struct lo_inode *lo_find(struct lo_data *lo, str= uct stat *st) if (p) { assert(p->nlookup > 0); p->nlookup++; + g_atomic_int_inc(&p->refcount); } pthread_mutex_unlock(&lo->mutex); =20 @@ -820,6 +871,10 @@ static void posix_locks_value_destroy(gpointer data) free(plock); } =20 +/* + * Increments nlookup and caller must release refcount using + * lo_inode_put(&parent). + */ static int lo_do_lookup(fuse_req_t req, fuse_ino_t parent, const char *nam= e, struct fuse_entry_param *e) { @@ -827,7 +882,8 @@ static int lo_do_lookup(fuse_req_t req, fuse_ino_t pare= nt, const char *name, int res; int saverr; struct lo_data *lo =3D lo_data(req); - struct lo_inode *inode, *dir =3D lo_inode(req, parent); + struct lo_inode *inode =3D NULL; + struct lo_inode *dir =3D lo_inode(req, parent); =20 /* * name_to_handle_at() and open_by_handle_at() can reach here with fus= e @@ -868,6 +924,13 @@ static int lo_do_lookup(fuse_req_t req, fuse_ino_t par= ent, const char *name, } =20 inode->is_symlink =3D S_ISLNK(e->attr.st_mode); + + /* + * One for the caller and one for nlookup (released in + * unref_inode_lolocked()) + */ + g_atomic_int_set(&inode->refcount, 2); + inode->nlookup =3D 1; inode->fd =3D newfd; newfd =3D -1; @@ -883,6 +946,8 @@ static int lo_do_lookup(fuse_req_t req, fuse_ino_t pare= nt, const char *name, pthread_mutex_unlock(&lo->mutex); } e->ino =3D inode->fuse_ino; + lo_inode_put(lo, &inode); + lo_inode_put(lo, &dir); =20 fuse_log(FUSE_LOG_DEBUG, " %lli/%s -> %lli\n", (unsigned long long)pa= rent, name, (unsigned long long)e->ino); @@ -894,6 +959,8 @@ out_err: if (newfd !=3D -1) { close(newfd); } + lo_inode_put(lo, &inode); + lo_inode_put(lo, &dir); return saverr; } =20 @@ -991,6 +1058,7 @@ static void lo_mknod_symlink(fuse_req_t req, fuse_ino_= t parent, { int res; int saverr; + struct lo_data *lo =3D lo_data(req); struct lo_inode *dir; struct fuse_entry_param e; struct lo_cred old =3D {}; @@ -1032,9 +1100,11 @@ static void lo_mknod_symlink(fuse_req_t req, fuse_in= o_t parent, name, (unsigned long long)e.ino); =20 fuse_reply_entry(req, &e); + lo_inode_put(lo, &dir); return; =20 out: + lo_inode_put(lo, &dir); fuse_reply_err(req, saverr); } =20 @@ -1085,6 +1155,7 @@ fallback: if (res !=3D -1) { res =3D linkat(parent->fd, path, dfd, name, 0); unref_inode_lolocked(lo, parent, 1); + lo_inode_put(lo, &parent); } =20 return res; @@ -1095,6 +1166,7 @@ static void lo_link(fuse_req_t req, fuse_ino_t ino, f= use_ino_t parent, { int res; struct lo_data *lo =3D lo_data(req); + struct lo_inode *parent_inode; struct lo_inode *inode; struct fuse_entry_param e; int saverr; @@ -1104,17 +1176,18 @@ static void lo_link(fuse_req_t req, fuse_ino_t ino,= fuse_ino_t parent, return; } =20 + parent_inode =3D lo_inode(req, parent); inode =3D lo_inode(req, ino); - if (!inode) { - fuse_reply_err(req, EBADF); - return; + if (!parent_inode || !inode) { + errno =3D EBADF; + goto out_err; } =20 memset(&e, 0, sizeof(struct fuse_entry_param)); e.attr_timeout =3D lo->timeout; e.entry_timeout =3D lo->timeout; =20 - res =3D linkat_empty_nofollow(lo, inode, lo_fd(req, parent), name); + res =3D linkat_empty_nofollow(lo, inode, parent_inode->fd, name); if (res =3D=3D -1) { goto out_err; } @@ -1133,13 +1206,18 @@ static void lo_link(fuse_req_t req, fuse_ino_t ino,= fuse_ino_t parent, name, (unsigned long long)e.ino); =20 fuse_reply_entry(req, &e); + lo_inode_put(lo, &parent_inode); + lo_inode_put(lo, &inode); return; =20 out_err: saverr =3D errno; + lo_inode_put(lo, &parent_inode); + lo_inode_put(lo, &inode); fuse_reply_err(req, saverr); } =20 +/* Increments nlookup and caller must release refcount using lo_inode_put(= ) */ static struct lo_inode *lookup_name(fuse_req_t req, fuse_ino_t parent, const char *name) { @@ -1176,6 +1254,7 @@ static void lo_rmdir(fuse_req_t req, fuse_ino_t paren= t, const char *name) =20 fuse_reply_err(req, res =3D=3D -1 ? errno : 0); unref_inode_lolocked(lo, inode, 1); + lo_inode_put(lo, &inode); } =20 static void lo_rename(fuse_req_t req, fuse_ino_t parent, const char *name, @@ -1183,8 +1262,10 @@ static void lo_rename(fuse_req_t req, fuse_ino_t par= ent, const char *name, unsigned int flags) { int res; - struct lo_inode *oldinode; - struct lo_inode *newinode; + struct lo_inode *parent_inode; + struct lo_inode *newparent_inode; + struct lo_inode *oldinode =3D NULL; + struct lo_inode *newinode =3D NULL; struct lo_data *lo =3D lo_data(req); =20 if (!is_safe_path_component(name) || !is_safe_path_component(newname))= { @@ -1192,6 +1273,13 @@ static void lo_rename(fuse_req_t req, fuse_ino_t par= ent, const char *name, return; } =20 + parent_inode =3D lo_inode(req, parent); + newparent_inode =3D lo_inode(req, newparent); + if (!parent_inode || !newparent_inode) { + fuse_reply_err(req, EBADF); + goto out; + } + oldinode =3D lookup_name(req, parent, name); newinode =3D lookup_name(req, newparent, newname); =20 @@ -1204,8 +1292,8 @@ static void lo_rename(fuse_req_t req, fuse_ino_t pare= nt, const char *name, #ifndef SYS_renameat2 fuse_reply_err(req, EINVAL); #else - res =3D syscall(SYS_renameat2, lo_fd(req, parent), name, - lo_fd(req, newparent), newname, flags); + res =3D syscall(SYS_renameat2, parent_inode->fd, name, + newparent_inode->fd, newname, flags); if (res =3D=3D -1 && errno =3D=3D ENOSYS) { fuse_reply_err(req, EINVAL); } else { @@ -1215,12 +1303,16 @@ static void lo_rename(fuse_req_t req, fuse_ino_t pa= rent, const char *name, goto out; } =20 - res =3D renameat(lo_fd(req, parent), name, lo_fd(req, newparent), newn= ame); + res =3D renameat(parent_inode->fd, name, newparent_inode->fd, newname)= ; =20 fuse_reply_err(req, res =3D=3D -1 ? errno : 0); out: unref_inode_lolocked(lo, oldinode, 1); unref_inode_lolocked(lo, newinode, 1); + lo_inode_put(lo, &oldinode); + lo_inode_put(lo, &newinode); + lo_inode_put(lo, &parent_inode); + lo_inode_put(lo, &newparent_inode); } =20 static void lo_unlink(fuse_req_t req, fuse_ino_t parent, const char *name) @@ -1244,6 +1336,7 @@ static void lo_unlink(fuse_req_t req, fuse_ino_t pare= nt, const char *name) =20 fuse_reply_err(req, res =3D=3D -1 ? errno : 0); unref_inode_lolocked(lo, inode, 1); + lo_inode_put(lo, &inode); } =20 static void unref_inode_lolocked(struct lo_data *lo, struct lo_inode *inod= e, @@ -1265,8 +1358,9 @@ static void unref_inode_lolocked(struct lo_data *lo, = struct lo_inode *inode, g_hash_table_destroy(inode->posix_locks); pthread_mutex_destroy(&inode->plock_mutex); pthread_mutex_unlock(&lo->mutex); - close(inode->fd); - free(inode); + + /* Drop our refcount from lo_do_lookup() */ + lo_inode_put(lo, &inode); } else { pthread_mutex_unlock(&lo->mutex); } @@ -1280,6 +1374,7 @@ static int unref_all_inodes_cb(gpointer key, gpointer= value, gpointer user_data) inode->nlookup =3D 0; lo_map_remove(&lo->ino_map, inode->fuse_ino); close(inode->fd); + lo_inode_put(lo, &inode); /* Drop our refcount from lo_do_lookup() */ =20 return TRUE; } @@ -1306,6 +1401,7 @@ static void lo_forget_one(fuse_req_t req, fuse_ino_t = ino, uint64_t nlookup) (unsigned long long)nlookup); =20 unref_inode_lolocked(lo, inode, nlookup); + lo_inode_put(lo, &inode); } =20 static void lo_forget(fuse_req_t req, fuse_ino_t ino, uint64_t nlookup) @@ -1537,6 +1633,7 @@ static void lo_do_readdir(fuse_req_t req, fuse_ino_t = ino, size_t size, err =3D 0; error: lo_dirp_put(&d); + lo_inode_put(lo, &dinode); =20 /* * If there's an error, we can only signal it if we haven't stored @@ -1595,6 +1692,7 @@ static void lo_create(fuse_req_t req, fuse_ino_t pare= nt, const char *name, { int fd; struct lo_data *lo =3D lo_data(req); + struct lo_inode *parent_inode; struct fuse_entry_param e; int err; struct lo_cred old =3D {}; @@ -1607,12 +1705,18 @@ static void lo_create(fuse_req_t req, fuse_ino_t pa= rent, const char *name, return; } =20 + parent_inode =3D lo_inode(req, parent); + if (!parent_inode) { + fuse_reply_err(req, EBADF); + return; + } + err =3D lo_change_cred(req, &old); if (err) { goto out; } =20 - fd =3D openat(lo_fd(req, parent), name, (fi->flags | O_CREAT) & ~O_NOF= OLLOW, + fd =3D openat(parent_inode->fd, name, (fi->flags | O_CREAT) & ~O_NOFOL= LOW, mode); err =3D fd =3D=3D -1 ? errno : 0; lo_restore_cred(&old); @@ -1625,8 +1729,8 @@ static void lo_create(fuse_req_t req, fuse_ino_t pare= nt, const char *name, pthread_mutex_unlock(&lo->mutex); if (fh =3D=3D -1) { close(fd); - fuse_reply_err(req, ENOMEM); - return; + err =3D ENOMEM; + goto out; } =20 fi->fh =3D fh; @@ -1639,6 +1743,8 @@ static void lo_create(fuse_req_t req, fuse_ino_t pare= nt, const char *name, } =20 out: + lo_inode_put(lo, &parent_inode); + if (err) { fuse_reply_err(req, err); } else { @@ -1712,16 +1818,18 @@ static void lo_getlk(fuse_req_t req, fuse_ino_t ino= , struct fuse_file_info *fi, plock =3D lookup_create_plock_ctx(lo, inode, fi->lock_owner, lock->l_pid, &r= et); if (!plock) { - pthread_mutex_unlock(&inode->plock_mutex); - fuse_reply_err(req, ret); - return; + saverr =3D ret; + goto out; } =20 ret =3D fcntl(plock->fd, F_OFD_GETLK, lock); if (ret =3D=3D -1) { saverr =3D errno; } + +out: pthread_mutex_unlock(&inode->plock_mutex); + lo_inode_put(lo, &inode); =20 if (saverr) { fuse_reply_err(req, saverr); @@ -1761,9 +1869,8 @@ static void lo_setlk(fuse_req_t req, fuse_ino_t ino, = struct fuse_file_info *fi, lookup_create_plock_ctx(lo, inode, fi->lock_owner, lock->l_pid, &r= et); =20 if (!plock) { - pthread_mutex_unlock(&inode->plock_mutex); - fuse_reply_err(req, ret); - return; + saverr =3D ret; + goto out; } =20 /* TODO: Is it alright to modify flock? */ @@ -1772,7 +1879,11 @@ static void lo_setlk(fuse_req_t req, fuse_ino_t ino,= struct fuse_file_info *fi, if (ret =3D=3D -1) { saverr =3D errno; } + +out: pthread_mutex_unlock(&inode->plock_mutex); + lo_inode_put(lo, &inode); + fuse_reply_err(req, saverr); } =20 @@ -1898,6 +2009,7 @@ static void lo_flush(fuse_req_t req, fuse_ino_t ino, = struct fuse_file_info *fi) pthread_mutex_unlock(&inode->plock_mutex); =20 res =3D close(dup(lo_fi_fd(req, fi))); + lo_inode_put(lo_data(req), &inode); fuse_reply_err(req, res =3D=3D -1 ? errno : 0); } =20 @@ -2115,11 +2227,14 @@ out_free: if (fd >=3D 0) { close(fd); } + + lo_inode_put(lo, &inode); return; =20 out_err: saverr =3D errno; out: + lo_inode_put(lo, &inode); fuse_reply_err(req, saverr); goto out_free; } @@ -2190,11 +2305,14 @@ out_free: if (fd >=3D 0) { close(fd); } + + lo_inode_put(lo, &inode); return; =20 out_err: saverr =3D errno; out: + lo_inode_put(lo, &inode); fuse_reply_err(req, saverr); goto out_free; } @@ -2243,6 +2361,8 @@ out: if (fd >=3D 0) { close(fd); } + + lo_inode_put(lo, &inode); fuse_reply_err(req, saverr); } =20 @@ -2289,6 +2409,8 @@ out: if (fd >=3D 0) { close(fd); } + + lo_inode_put(lo, &inode); fuse_reply_err(req, saverr); } =20 @@ -2671,6 +2793,7 @@ static void setup_root(struct lo_data *lo, struct lo_= inode *root) root->key.ino =3D stat.st_ino; root->key.dev =3D stat.st_dev; root->nlookup =3D 2; + g_atomic_int_set(&root->refcount, 2); } =20 static guint lo_key_hash(gconstpointer key) --=20 2.24.1