From: Xiangsheng Hou <xiangsheng.hou@mediatek.com>
Date: Mon, 7 Apr 2025 11:50:49 +0000 (+0800)
Subject: virtiofs: add filesystem context source name check
X-Git-Tag: v6.15-rc3~49^2~9
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=a94fd938df2b1628da66b498aa0eeb89593bc7a2;p=thirdparty%2Fkernel%2Flinux.git

virtiofs: add filesystem context source name check

In certain scenarios, for example, during fuzz testing, the source
name may be NULL, which could lead to a kernel panic. Therefore, an
extra check for the source name should be added.

Fixes: a62a8ef9d97d ("virtio-fs: add virtiofs filesystem")
Cc: <stable@vger.kernel.org> # all LTS kernels
Signed-off-by: Xiangsheng Hou <xiangsheng.hou@mediatek.com>
Link: https://lore.kernel.org/20250407115111.25535-1-xiangsheng.hou@mediatek.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
---

diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c
index 2c7b24cb67adb..53c2626e90e72 100644
--- a/fs/fuse/virtio_fs.c
+++ b/fs/fuse/virtio_fs.c
@@ -1669,6 +1669,9 @@ static int virtio_fs_get_tree(struct fs_context *fsc)
 	unsigned int virtqueue_size;
 	int err = -EIO;
 
+	if (!fsc->source)
+		return invalf(fsc, "No source specified");
+
 	/* This gets a reference on virtio_fs object. This ptr gets installed
 	 * in fc->iq->priv. Once fuse_conn is going away, it calls ->put()
 	 * to drop the reference to this object.