From 4f8672201b7e7ed4f5f6c3cf6dcd080648580582 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Fri, 6 Apr 2018 16:37:21 -0700 Subject: [PATCH] libnvdimm, namespace: use a safe lookup for dimm device name The following NULL dereference results from incorrectly assuming that ndd is valid in this print: struct nvdimm_drvdata *ndd = to_ndd(&nd_region->mapping[i]); /* * Give up if we don't find an instance of a uuid at each * position (from 0 to nd_region->ndr_mappings - 1), or if we * find a dimm with two instances of the same uuid. */ dev_err(&nd_region->dev, "%s missing label for %pUb\n", dev_name(ndd->dev), nd_label->uuid); BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 IP: nd_region_register_namespaces+0xd67/0x13c0 [libnvdimm] PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI CPU: 43 PID: 673 Comm: kworker/u609:10 Not tainted 4.16.0-rc4+ #1 [..] RIP: 0010:nd_region_register_namespaces+0xd67/0x13c0 [libnvdimm] [..] Call Trace: ? devres_add+0x2f/0x40 ? devm_kmalloc+0x52/0x60 ? nd_region_activate+0x9c/0x320 [libnvdimm] nd_region_probe+0x94/0x260 [libnvdimm] ? kernfs_add_one+0xe4/0x130 nvdimm_bus_probe+0x63/0x100 [libnvdimm] Switch to using the nvdimm device directly. Fixes: 0e3b0d123c8f ("libnvdimm, namespace: allow multiple pmem...") Cc: Reported-by: Dave Jiang Signed-off-by: Dan Williams --- drivers/nvdimm/namespace_devs.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c index 89b40ff83025..28afdd668905 100644 --- a/drivers/nvdimm/namespace_devs.c +++ b/drivers/nvdimm/namespace_devs.c @@ -1921,7 +1921,7 @@ static struct device *create_namespace_pmem(struct nd_region *nd_region, } if (i < nd_region->ndr_mappings) { - struct nvdimm_drvdata *ndd = to_ndd(&nd_region->mapping[i]); + struct nvdimm *nvdimm = nd_region->mapping[i].nvdimm; /* * Give up if we don't find an instance of a uuid at each @@ -1929,7 +1929,7 @@ static struct device *create_namespace_pmem(struct nd_region *nd_region, * find a dimm with two instances of the same uuid. */ dev_err(&nd_region->dev, "%s missing label for %pUb\n", - dev_name(ndd->dev), nd_label->uuid); + nvdimm_name(nvdimm), nd_label->uuid); rc = -EINVAL; goto err; } -- 2.30.2