From: Daniel Wagner <dwagner@suse.de> [ Upstream commit 85428beac80dbcace5b146b218697c73e367dcf5 ] Reset the ns->file value to NULL also in the error case in nvmet_file_ns_enable(). The ns->file variable points either to file object or contains the error code after the filp_open() call. This can lead to following problem: When the user first setups an invalid file backend and tries to enable the ns, it will fail. Then the user switches over to a bdev backend and enables successfully the ns. The first received I/O will crash the system because the IO backend is chosen based on the ns->file value: static u16 nvmet_parse_io_cmd(struct nvmet_req *req) { [...] if (req->ns->file) return nvmet_file_parse_io_cmd(req); return nvmet_bdev_parse_io_cmd(req); } Reported-by: Enzo Matsumiya <ematsumiya@suse.com> Signed-off-by: Daniel Wagner <dwagner@suse.de> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- drivers/nvme/target/io-cmd-file.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/nvme/target/io-cmd-file.c b/drivers/nvme/target/io-cmd-file.c index 39d972e2595f0..ad6263cf7303c 100644 --- a/drivers/nvme/target/io-cmd-file.c +++ b/drivers/nvme/target/io-cmd-file.c @@ -38,9 +38,11 @@ int nvmet_file_ns_enable(struct nvmet_ns *ns) ns->file = filp_open(ns->device_path, flags, 0); if (IS_ERR(ns->file)) { - pr_err("failed to open file %s: (%ld)\n", - ns->device_path, PTR_ERR(ns->file)); - return PTR_ERR(ns->file); + ret = PTR_ERR(ns->file); + pr_err("failed to open file %s: (%d)\n", + ns->device_path, ret); + ns->file = NULL; + return ret; } ret = vfs_getattr(&ns->file->f_path, -- 2.25.1