>From b15b244d6e6e20964bd4b85306722cb60c3c0809 Mon Sep 17 00:00:00 2001
From: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Date: Mon, 2 Apr 2012 13:28:18 +1000
Subject:
Under some circumstances, pci_map_rom() can return a valid mapping
but a size of 0 (if it cannot find an image in the header).
This causes nouveau to try to kmalloc() a 0 sized pointer and
dereference it, which crashes.
Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
---
Please send to Linus asap, without this, it crashes on the G5
drivers/gpu/drm/nouveau/nouveau_bios.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/nouveau/nouveau_bios.c b/drivers/gpu/drm/nouveau/nouveau_bios.c
index 637afe7..80963d0 100644
--- a/drivers/gpu/drm/nouveau/nouveau_bios.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bios.c
@@ -177,14 +177,15 @@ bios_shadow_pci(struct nvbios *bios)
if (!pci_enable_rom(pdev)) {
void __iomem *rom = pci_map_rom(pdev, &length);
- if (rom) {
+ if (rom && length) {
bios->data = kmalloc(length, GFP_KERNEL);
if (bios->data) {
memcpy_fromio(bios->data, rom, length);
bios->length = length;
}
- pci_unmap_rom(pdev, rom);
}
+ if (rom)
+ pci_unmap_rom(pdev, rom);
pci_disable_rom(pdev);
}
--
1.7.9.5
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