From 96dc2ca70906c831b60be1c6ed3a27dbf7628e72 Mon Sep 17 00:00:00 2001
From: Sebastian Lackner
Date: Mon, 11 Dec 2017 03:56:31 +0100
Subject: fusefrontend_reverse: Reject access to device nodes in newFile
function
Steps to reproduce:
* Create a regular reverse mount point
* Create a file "test" in the original directory
* Access the corresponding encrypted directory in the mount point (ls <encrypted dir>)
* Quickly delete the file in the original data - instead create a device node
* Access the file again, it will access the device node and attempt to read from it
Fixes https://github.com/rfjakob/gocryptfs/issues/187
---
internal/fusefrontend_reverse/rfile.go | 8 ++++++++
1 file changed, 8 insertions(+)
(limited to 'internal/fusefrontend_reverse')
diff --git a/internal/fusefrontend_reverse/rfile.go b/internal/fusefrontend_reverse/rfile.go
index c10d341..26756a3 100644
--- a/internal/fusefrontend_reverse/rfile.go
+++ b/internal/fusefrontend_reverse/rfile.go
@@ -51,6 +51,14 @@ func (rfs *ReverseFS) newFile(relPath string) (*reverseFile, fuse.Status) {
syscall.Close(fd)
return nil, fuse.ToStatus(err)
}
+ // Reject access if the file descriptor does not refer to a regular file.
+ var a fuse.Attr
+ a.FromStat(&st)
+ if !a.IsRegular() {
+ tlog.Warn.Printf("ino%d: newFile: not a regular file", st.Ino)
+ syscall.Close(fd)
+ return nil, fuse.ToStatus(syscall.EACCES)
+ }
// See if we have that inode number already in the table
// (even if Nlink has dropped to 1)
var derivedIVs pathiv.FileIVs
--
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