From 851783a0c4ffb87a8d8065f9bf286c2aa546a542 Mon Sep 17 00:00:00 2001
From: Hangyu Hua <hbh25y@gmail.com>
Date: Thu, 16 Nov 2023 15:57:26 +0800
Subject: [PATCH] fuse: dax: set fc->dax to NULL in fuse_dax_conn_free()
commit 7f8ed28d1401320bcb02dda81b3c23ab2dc5a6d8 upstream.
fuse_dax_conn_free() will be called when fuse_fill_super_common() fails
after fuse_dax_conn_alloc(). Then deactivate_locked_super() in
virtio_fs_get_tree() will call virtio_kill_sb() to release the discarded
superblock. This will call fuse_dax_conn_free() again in fuse_conn_put(),
resulting in a possible double free.
Fixes: 1dd539577c42 ("virtiofs: add a mount option to enable dax")
Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Cc: <stable@vger.kernel.org> # v5.10
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/fuse/dax.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/fs/fuse/dax.c b/fs/fuse/dax.c
index ff99ab2a3c43..2739e218df64 100644
--- a/fs/fuse/dax.c
+++ b/fs/fuse/dax.c
@@ -1228,6 +1228,7 @@ void fuse_dax_conn_free(struct fuse_conn *fc)
if (fc->dax) {
fuse_free_dax_mem_ranges(&fc->dax->free_ranges);
kfree(fc->dax);
+ fc->dax = NULL;
}
}