[PATCH 1/2] gpib: ines: check CIS register mapping

[Ruoyu Wang]

ines_gpib_config() maps the PCMCIA attribute-memory window and then
writes the I/O window base through the returned pointer. If ioremap()
fails, the writeb() dereferences a NULL mapping.

Check the mapping result and unwind the partially configured device
before returning -ENOMEM.

Signed-off-by: Ruoyu Wang <ruoyuw560@xxxxxxxxx>
---
 drivers/gpib/ines/ines_gpib.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpib/ines/ines_gpib.c b/drivers/gpib/ines/ines_gpib.c
index c000f647f..0968a247e 100644
--- a/drivers/gpib/ines/ines_gpib.c
+++ b/drivers/gpib/ines/ines_gpib.c
@@ -1145,6 +1145,10 @@ static int ines_gpib_config(struct pcmcia_device *link)
 		return -ENODEV;
 	}
 	virt = ioremap(link->resource[2]->start, resource_size(link->resource[2]));
+	if (!virt) {
+		ines_gpib_release(link);
+		return -ENOMEM;
+	}
 	writeb((link->resource[2]->start >> 2) & 0xff, virt + 0xf0); // IOWindow base
 	iounmap(virt);
 
-- 
2.51.0