Skip to content

fix(mmio): don't return MMIO virtual addresses to the free list (use-after-free) #2255

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
edef1c wants to merge 1 commit into
base: main
Choose a base branch
from
Open

fix(mmio): don't return MMIO virtual addresses to the free list (use-after-free) #2255

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
10 changes: 8 additions & 2 deletions src/arch/x86_64/kernel/mmio.rs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -98,8 +98,8 @@ fn check_linux_args(
linux_mmio: &'static [String],
) -> Vec<(VolatileRef<'static, DeviceRegisters>, u8)> {
let layout = PageLayout::from_size(BasePageSize::SIZE as usize).unwrap();
let page_range = PageBox::new(layout).unwrap();
let virtual_address = VirtAddr::from(page_range.start());
let mut page_range = PageBox::new(layout).unwrap();
let mut virtual_address = VirtAddr::from(page_range.start());

let mut devices = vec![];
for arg in linux_mmio {
Expand Down Expand Up @@ -138,6 +138,12 @@ fn check_linux_args(
FrameAlloc::allocate_at(frame_range).unwrap_err();
}

// Don't return the VA to the free list: the driver holds a VolatileRef into this mapping.
PageBox::into_raw(page_range);
// Pick a fresh VA for subsequent iterations.
page_range = PageBox::new(layout).unwrap();
virtual_address = VirtAddr::from(page_range.start());

devices.push((mmio, irq));
}
_ => {
Expand Down
Loading