In current code, the pointer ndns is being dereferenced on the initialization of pointer parent_uuid before ndns is null check. This could lead to a potential null pointer dereference. Fix this by dereferencing ndns after ndns has been null pointer sanity checked.
Signed-off-by: Jing Xiangfeng <[email protected]> --- drivers/nvdimm/pfn_devs.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/nvdimm/pfn_devs.c b/drivers/nvdimm/pfn_devs.c index 3e11ef8d3f5b..c443994f81f3 100644 --- a/drivers/nvdimm/pfn_devs.c +++ b/drivers/nvdimm/pfn_devs.c @@ -452,7 +452,7 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig) unsigned long align, start_pad; struct nd_pfn_sb *pfn_sb = nd_pfn->pfn_sb; struct nd_namespace_common *ndns = nd_pfn->ndns; - const u8 *parent_uuid = nd_dev_to_uuid(&ndns->dev); + const u8 *parent_uuid; if (!pfn_sb || !ndns) return -ENODEV; @@ -472,6 +472,7 @@ int nd_pfn_validate(struct nd_pfn *nd_pfn, const char *sig) return -ENODEV; pfn_sb->checksum = cpu_to_le64(checksum); + parent_uuid = nd_dev_to_uuid(&ndns->dev); if (memcmp(pfn_sb->parent_uuid, parent_uuid, 16) != 0) return -ENODEV; -- 2.17.1
