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From: "Dr. David Alan Gilbert (git)" <dgilbert@redhat.com>
To: qemu-devel@nongnu.org, renzhen@linux.alibaba.com,
	eguan@linux.alibaba.com, ganesh.mahalingam@intel.com,
	m.mizuma@jp.fujitsu.com, mszeredi@redhat.com,
	misono.tomohiro@jp.fujitsu.com, tao.peng@linux.alibaba.com,
	piaojun@huawei.com, stefanha@redhat.com, vgoyal@redhat.com,
	mst@redhat.com, berrange@redhat.com
Subject: [PATCH 13/25] virtiofsd: prevent ".." escape in lo_do_lookup()
Date: Thu, 24 Oct 2019 12:27:06 +0100	[thread overview]
Message-ID: <20191024112718.34657-14-dgilbert@redhat.com> (raw)
In-Reply-To: <20191024112718.34657-1-dgilbert@redhat.com>

From: Stefan Hajnoczi <stefanha@redhat.com>

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 contrib/virtiofsd/passthrough_ll.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/contrib/virtiofsd/passthrough_ll.c b/contrib/virtiofsd/passthrough_ll.c
index 702fedc38a..7a61bf94fe 100644
--- a/contrib/virtiofsd/passthrough_ll.c
+++ b/contrib/virtiofsd/passthrough_ll.c
@@ -606,12 +606,17 @@ static int lo_do_lookup(fuse_req_t req, fuse_ino_t parent, const char *name,
 	int res;
 	int saverr;
 	struct lo_data *lo = lo_data(req);
-	struct lo_inode *inode;
+	struct lo_inode *inode, *dir = lo_inode(req, parent);
 
 	memset(e, 0, sizeof(*e));
 	e->attr_timeout = lo->timeout;
 	e->entry_timeout = lo->timeout;
 
+	/* Do not allow escaping root directory */
+	if (dir == &lo->root && strcmp(name, "..") == 0) {
+		name = ".";
+	}
+
 	newfd = openat(lo_fd(req, parent), name, O_PATH | O_NOFOLLOW);
 	if (newfd == -1)
 		goto out_err;
-- 
2.23.0



  parent reply	other threads:[~2019-10-24 12:21 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-24 11:26 [PATCH 00/25] virtiofs daemon (security) Dr. David Alan Gilbert (git)
2019-10-24 11:26 ` [PATCH 01/25] virtiofsd: passthrough_ll: create new files in caller's context Dr. David Alan Gilbert (git)
2019-10-24 11:26 ` [PATCH 02/25] virtiofsd: passthrough_ll: add lo_map for ino/fh indirection Dr. David Alan Gilbert (git)
2019-10-24 11:26 ` [PATCH 03/25] virtiofsd: passthrough_ll: add ino_map to hide lo_inode pointers Dr. David Alan Gilbert (git)
2019-10-24 11:26 ` [PATCH 04/25] virtiofsd: passthrough_ll: add dirp_map to hide lo_dirp pointers Dr. David Alan Gilbert (git)
2019-10-24 11:26 ` [PATCH 05/25] virtiofsd: passthrough_ll: add fd_map to hide file descriptors Dr. David Alan Gilbert (git)
2019-10-24 11:26 ` [PATCH 06/25] virtiofsd: passthrough_ll: add fallback for racy ops Dr. David Alan Gilbert (git)
2019-10-24 11:27 ` [PATCH 07/25] virtiofsd: validate path components Dr. David Alan Gilbert (git)
2019-10-24 11:27 ` [PATCH 08/25] virtiofsd: Plumb fuse_bufvec through to do_write_buf Dr. David Alan Gilbert (git)
2019-10-24 11:27 ` [PATCH 09/25] virtiofsd: Pass write iov's all the way through Dr. David Alan Gilbert (git)
2019-10-24 11:27 ` [PATCH 10/25] virtiofsd: add fuse_mbuf_iter API Dr. David Alan Gilbert (git)
2019-10-24 11:27 ` [PATCH 11/25] virtiofsd: validate input buffer sizes in do_write_buf() Dr. David Alan Gilbert (git)
2019-10-24 11:27 ` [PATCH 12/25] virtiofsd: check input buffer size in fuse_lowlevel.c ops Dr. David Alan Gilbert (git)
2019-10-24 11:27 ` Dr. David Alan Gilbert (git) [this message]
2019-10-24 11:27 ` [PATCH 14/25] virtiofsd: prevent ".." escape in lo_do_readdir() Dr. David Alan Gilbert (git)
2019-10-24 11:27 ` [PATCH 15/25] virtiofsd: use /proc/self/fd/ O_PATH file descriptor Dr. David Alan Gilbert (git)
2019-10-24 11:27 ` [PATCH 16/25] virtiofsd: sandbox mount namespace Dr. David Alan Gilbert (git)
2019-10-24 11:27 ` [PATCH 17/25] virtiofsd: move to an empty network namespace Dr. David Alan Gilbert (git)
2019-10-24 11:27 ` [PATCH 18/25] virtiofsd: move to a new pid namespace Dr. David Alan Gilbert (git)
2019-10-24 11:27 ` [PATCH 19/25] virtiofsd: add seccomp whitelist Dr. David Alan Gilbert (git)
2019-10-24 11:27 ` [PATCH 20/25] virtiofsd: Parse flag FUSE_WRITE_KILL_PRIV Dr. David Alan Gilbert (git)
2019-10-24 11:27 ` [PATCH 21/25] virtiofsd: Drop CAP_FSETID if client asked for it Dr. David Alan Gilbert (git)
2019-10-24 11:27 ` [PATCH 22/25] virtiofsd: set maximum RLIMIT_NOFILE limit Dr. David Alan Gilbert (git)
2019-10-24 11:27 ` [PATCH 23/25] virtiofsd: add security guide document Dr. David Alan Gilbert (git)
2019-10-24 11:27 ` [PATCH 24/25] virtiofsd: add --syslog command-line option Dr. David Alan Gilbert (git)
2019-10-24 11:27 ` [PATCH 25/25] virtiofsd: print log only when priority is high enough Dr. David Alan Gilbert (git)

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