[PATCH AUTOSEL 4.4 44/56] video: imsttfb: fix potential NULL pointer dereferences

[Sasha Levin]

From: Kangjie Lu <kjlu at umn.edu>

[ Upstream commit 1d84353d205a953e2381044953b7fa31c8c9702d ]

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

Signed-off-by: Kangjie Lu <kjlu at umn.edu>
Cc: Aditya Pakki <pakki001 at umn.edu>
Cc: Finn Thain <fthain at telegraphics.com.au>
Cc: Rob Herring <robh at kernel.org>
Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
[b.zolnierkie: minor patch summary fixup]
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie at samsung.com>
Signed-off-by: Sasha Levin <sashal at kernel.org>
---
 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 9b167f7ef6c69..4994a540f6809 100644
--- a/drivers/video/fbdev/imsttfb.c
+++ b/drivers/video/fbdev/imsttfb.c
@@ -1517,6 +1517,11 @@ 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;
-- 
2.20.1