Re: [PATCH] nvdimm: fix possible null-ptr-deref in nd_dax_probe()

[yiyang (D)]

On 2024/10/28 22:17, Ira Weiny wrote:

Yi Yang wrote:

It will cause null-ptr-deref when nd_dax_alloc() returns NULL, fix it by
add check for nd_dax_alloc().

Was this found with a real workload or just by inspection?

Ira

I just found the problem by reading the code.

Regards,
Yiyang

Fixes: c5ed9268643c ("libnvdimm, dax: autodetect support")
Signed-off-by: Yi Yang <yiyan...@huawei.com>
---
  drivers/nvdimm/dax_devs.c | 4 ++++
  1 file changed, 4 insertions(+)

diff --git a/drivers/nvdimm/dax_devs.c b/drivers/nvdimm/dax_devs.c
index 6b4922de3047..70a7e401f90d 100644
--- a/drivers/nvdimm/dax_devs.c
+++ b/drivers/nvdimm/dax_devs.c
@@ -106,6 +106,10 @@ int nd_dax_probe(struct device *dev, struct 
nd_namespace_common *ndns)

nvdimm_bus_lock(&ndns->dev);

        nd_dax = nd_dax_alloc(nd_region);
+       if (!nd_dax) {
+               nvdimm_bus_unlock(&ndns->dev);
+               return -ENOMEM;
+       }
        nd_pfn = &nd_dax->nd_pfn;
        dax_dev = nd_pfn_devinit(nd_pfn, ndns);
        nvdimm_bus_unlock(&ndns->dev);
--
2.25.1

.