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

From: Sasha Levin
Date: Sat Jun 01 2019 - 09:31:47 EST


From: Kangjie Lu <kjlu@xxxxxxx>

[ 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@xxxxxxx>
Cc: Aditya Pakki <pakki001@xxxxxxx>
Cc: Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx>
Cc: Rob Herring <robh@xxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
[b.zolnierkie: minor patch summary fixup]
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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