nvme: host: fix double-free of struct nvme_id_ns in ns_update_nuse()

When nvme_identify_ns() fails, it frees the pointer to the struct
nvme_id_ns before it returns. However, ns_update_nuse() calls kfree()
for the pointer even when nvme_identify_ns() fails. This results in
KASAN double-free, which was observed with blktests nvme/045 with
proposed patches [1] on the kernel v6.8-rc7. Fix the double-free by
skipping kfree() when nvme_identify_ns() fails.

Link: https://lore.kernel.org/linux-block/20240304161303.19681-1-dwagner@suse.de/
Fixes: a1a825ab6a60 ("nvme: add csi, ms and nuse to sysfs")
Signed-off-by: Shin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>

diff --git a/drivers/nvme/host/sysfs.c b/drivers/nvme/host/sysfs.c
index d099218..6c7f1d5 100644 (file)
--- a/drivers/nvme/host/sysfs.c
+++ b/drivers/nvme/host/sysfs.c
@@ -221,14 +221,11 @@ static int ns_update_nuse(struct nvme_ns *ns)
 
        ret = nvme_identify_ns(ns->ctrl, ns->head->ns_id, &id);
        if (ret)
-               goto out_free_id;
+               return ret;
 
        ns->head->nuse = le64_to_cpu(id->nuse);
-
-out_free_id:
        kfree(id);
-
-       return ret;
+       return 0;
 }
 
 static ssize_t nuse_show(struct device *dev, struct device_attribute *attr,