From: Gerd Hoffmann <kraxel@xxxxxxxxxx>
[ Upstream commit 05b252cccb2e5c3f56119d25de684b4f810ba40a ]
Check vm_fault->pgoff before using it. When we removed the warning, we
also removed the check.
Fixes: 7b26e4e2119d ("udmabuf: drop WARN_ON() check.")
Reported-by: zdi-disclosures@xxxxxxxxxxxxxx
Suggested-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Gerd Hoffmann <kraxel@xxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/dma-buf/udmabuf.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c
index e7330684d3b8..9631f2fd2faf 100644
--- a/drivers/dma-buf/udmabuf.c
+++ b/drivers/dma-buf/udmabuf.c
@@ -32,8 +32,11 @@ static vm_fault_t udmabuf_vm_fault(struct vm_fault *vmf)
{
struct vm_area_struct *vma = vmf->vma;
struct udmabuf *ubuf = vma->vm_private_data;
+ pgoff_t pgoff = vmf->pgoff;
- vmf->page = ubuf->pages[vmf->pgoff];
+ if (pgoff >= ubuf->pagecount)
+ return VM_FAULT_SIGBUS;
+ vmf->page = ubuf->pages[pgoff];
get_page(vmf->page);
return 0;
}
--
2.35.1
