[PATCH] video: fbdev: fix potential NULL pointer dereferences

In case ioremap fails, the fix releases resources and returns
-ENOMEM to avoid NULL pointer dereferences.

Signed-off-by: Kangjie Lu <redacted>
---
 drivers/video/fbdev/imsttfb.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/video/fbdev/imsttfb.c b/drivers/video/fbdev/imsttfb.c
index 5d9670daf60e..2e321d73b3a5 100644
--- a/drivers/video/fbdev/imsttfb.c
+++ b/drivers/video/fbdev/imsttfb.c

@@ -1515,6 +1515,11 @@ static int imsttfb_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	info->fix.smem_start = addr;
 	info->screen_base = (__u8 *)ioremap(addr, par->ramdac = IBM ?
 					    0x400000 : 0x800000);
+	if (!info->screen_base) {
+		release_mem_region(addr, size);
+		framebuffer_release(info);
+		return -ENOMEM;
+	}
 	info->fix.mmio_start = addr + 0x800000;
 	par->dc_regs = ioremap(addr + 0x800000, 0x1000);
 	par->cmap_regs_phys = addr + 0x840000;

-- 
2.17.1

On 03/14/2019 08:33 AM, Kangjie Lu wrote:

In case ioremap fails, the fix releases resources and returns
-ENOMEM to avoid NULL pointer dereferences.

Signed-off-by: Kangjie Lu <redacted>

Patch queued for v5.2 with minor change in the patch summary
("video: imsttfb: fix potential NULL pointer dereference"), thanks.

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics