| Message ID | 20250603221949.53272-2-Smita.KoralahalliChannabasappa@amd.com |
|---|---|
| State | New |
| Headers | show |
| Series | Add managed SOFT RESERVE resource handling | expand |
On 6/3/25 3:19 PM, Smita Koralahalli wrote: > Add a NULL check in is_cxl_region() to prevent potential null pointer > dereference if a caller passes a NULL device. This change ensures the > function safely returns false instead of triggering undefined behavior > when dev is NULL. Don't think this change is necessary. The code paths should not be hitting any NULL region devices unless it's a programming error. > > Co-developed-by: Nathan Fontenot <Nathan.Fontenot@amd.com> > Signed-off-by: Nathan Fontenot <Nathan.Fontenot@amd.com> > Co-developed-by: Terry Bowman <terry.bowman@amd.com> > Signed-off-by: Terry Bowman <terry.bowman@amd.com> > Signed-off-by: Smita Koralahalli <Smita.KoralahalliChannabasappa@amd.com> > --- > drivers/cxl/core/region.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c > index c3f4dc244df7..109b8a98c4c7 100644 > --- a/drivers/cxl/core/region.c > +++ b/drivers/cxl/core/region.c > @@ -2333,7 +2333,7 @@ const struct device_type cxl_region_type = { > > bool is_cxl_region(struct device *dev) > { > - return dev->type == &cxl_region_type; > + return dev && dev->type == &cxl_region_type; > } > EXPORT_SYMBOL_NS_GPL(is_cxl_region, "CXL"); >
On 6/3/2025 6:49 PM, Dave Jiang wrote: > > > On 6/3/25 3:19 PM, Smita Koralahalli wrote: >> Add a NULL check in is_cxl_region() to prevent potential null pointer >> dereference if a caller passes a NULL device. This change ensures the >> function safely returns false instead of triggering undefined behavior >> when dev is NULL. > > Don't think this change is necessary. The code paths should not be hitting any NULL region devices unless it's a programming error. I originally added this to the patchset during some initial development to handle possible NULL dev pointers when updating soft reserve resources, see cxl_region_softreserv_update() in patch 5/7. In the current form of the that routine it appears we shouldn't execute the while loop if dev is NULL so this could get from the patch set. -Nathan > >> >> Co-developed-by: Nathan Fontenot <Nathan.Fontenot@amd.com> >> Signed-off-by: Nathan Fontenot <Nathan.Fontenot@amd.com> >> Co-developed-by: Terry Bowman <terry.bowman@amd.com> >> Signed-off-by: Terry Bowman <terry.bowman@amd.com> >> Signed-off-by: Smita Koralahalli <Smita.KoralahalliChannabasappa@amd.com> >> --- >> drivers/cxl/core/region.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c >> index c3f4dc244df7..109b8a98c4c7 100644 >> --- a/drivers/cxl/core/region.c >> +++ b/drivers/cxl/core/region.c >> @@ -2333,7 +2333,7 @@ const struct device_type cxl_region_type = { >> >> bool is_cxl_region(struct device *dev) >> { >> - return dev->type == &cxl_region_type; >> + return dev && dev->type == &cxl_region_type; >> } >> EXPORT_SYMBOL_NS_GPL(is_cxl_region, "CXL"); >> >
diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c index c3f4dc244df7..109b8a98c4c7 100644 --- a/drivers/cxl/core/region.c +++ b/drivers/cxl/core/region.c @@ -2333,7 +2333,7 @@ const struct device_type cxl_region_type = { bool is_cxl_region(struct device *dev) { - return dev->type == &cxl_region_type; + return dev && dev->type == &cxl_region_type; } EXPORT_SYMBOL_NS_GPL(is_cxl_region, "CXL");