From 99d3552dce0919b5d424fdc77df3fd77b9c59393 Mon Sep 17 00:00:00 2001
From: Miklos Szeredi <mszeredi@redhat.com>
Date: Tue, 19 May 2020 14:50:37 +0200
Subject: [PATCH] fuse: always allow query of st_dev
Fuse mounts without "allow_other" are off-limits to all non-owners. Yet it
makes sense to allow querying st_dev on the root, since this value is
provided by the kernel, not the userspace filesystem.
Allow statx(2) with a zero request mask to succeed on a fuse mounts for all
users.
Reported-by: Nikolaus Rath <Nikolaus@rath.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
---
fs/fuse/dir.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index de1e2fde60bd4..26f028bc760b2 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -1689,8 +1689,18 @@ static int fuse_getattr(const struct path *path, struct kstat *stat,
struct inode *inode = d_inode(path->dentry);
struct fuse_conn *fc = get_fuse_conn(inode);
- if (!fuse_allow_current_process(fc))
+ if (!fuse_allow_current_process(fc)) {
+ if (!request_mask) {
+ /*
+ * If user explicitly requested *nothing* then don't
+ * error out, but return st_dev only.
+ */
+ stat->result_mask = 0;
+ stat->dev = inode->i_sb->s_dev;
+ return 0;
+ }
return -EACCES;
+ }
return fuse_update_get_attr(inode, NULL, stat, request_mask, flags);
}
--
GitLab