| Message ID | 20180724134006.GA2775@embeddedor.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | libnvdimm: fix NULL pointer dereference | expand |
On Tue, Jul 24, 2018 at 08:40:06AM -0500, Gustavo A. R. Silva wrote: > ndd is being dereferenced before it is null checked, hence there is a > potential null pointer dereference. > > Fix this by moving the pointer dereference after ndd has been properly > null checked at line 554: if (!ndd) I'll fold this into v4 of the patch since Vishal found an issue when a DIMM has multiple regions.
diff --git a/drivers/nvdimm/dimm_devs.c b/drivers/nvdimm/dimm_devs.c index 9e977cb..1dc3125 100644 --- a/drivers/nvdimm/dimm_devs.c +++ b/drivers/nvdimm/dimm_devs.c @@ -546,7 +546,7 @@ resource_size_t nd_pmem_max_contiguous_dpa(struct nd_region *nd_region, struct nd_mapping *nd_mapping) { struct nvdimm_drvdata *ndd = to_ndd(nd_mapping); - struct nvdimm_bus *nvdimm_bus = walk_to_nvdimm_bus(ndd->dev); + struct nvdimm_bus *nvdimm_bus; resource_size_t max = 0; struct resource *res; @@ -554,6 +554,8 @@ resource_size_t nd_pmem_max_contiguous_dpa(struct nd_region *nd_region, if (!ndd) return 0; + nvdimm_bus = walk_to_nvdimm_bus(ndd->dev); + if (reserve_free_pmem(nvdimm_bus, nd_mapping)) return 0; for_each_dpa_resource(ndd, res) {
ndd is being dereferenced before it is null checked, hence there is a potential null pointer dereference. Fix this by moving the pointer dereference after ndd has been properly null checked at line 554: if (!ndd) Addresses-Coverity-ID: 1472020 ("Dereference before null check") Fixes: 42218e643bd2 ("libnvdimm: Use max contiguous area for namespace size") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> --- drivers/nvdimm/dimm_devs.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)