qemu/0055-virtiofsd-prevent-.-escape-in-lo_do_lookup.patch
Cole Robinson 1d442bb612 qemu-4.2.0-4.fc32
virtio-fs support from upstream
2020-01-28 10:36:21 -05:00

36 lines
1.3 KiB
Diff

From: Stefan Hajnoczi <stefanha@redhat.com>
Date: Mon, 27 Jan 2020 19:01:24 +0000
Subject: [PATCH] virtiofsd: prevent ".." escape in lo_do_lookup()
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Sergio Lopez <slp@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
(cherry picked from commit 854684bc0b3d63eb90b3abdfe471c2e4271ef176)
---
tools/virtiofsd/passthrough_ll.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/tools/virtiofsd/passthrough_ll.c b/tools/virtiofsd/passthrough_ll.c
index e375406160..79d5966eea 100644
--- a/tools/virtiofsd/passthrough_ll.c
+++ b/tools/virtiofsd/passthrough_ll.c
@@ -624,12 +624,17 @@ 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;