From: Daniel Wagner dwagner@suse.de
stable inclusion from linux-4.19.192 commit 6671cd54fd21fe8c31fa5c4b28d3c7e96945cd35
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[ 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,