Dylan Reid 326cd88074 virtio-devices: balloon: Clamp range to region before PUNCH_HOLE ...

release_memory_range took (range_base, range_len) verbatim from a
guest-controlled descriptor (free-page-reporting and inflate paths) and
called fallocate(PUNCH_HOLE | KEEP_SIZE) on the backing file before any
length check ran. find_region only validates that range_base lands
inside *some* region; range_len can extend past the region's end. When
the operator uses --memory-zone file=PATH against a host file larger
than the zone, the punch zeroes host file content past the guest's
memory extent.

Free-page reporting is advisory, so the VMM is allowed to act on a
subset of a free range. Clamp range_len to the bytes that actually fit
within the region returned by find_region. Going past the end of a
region is most likely a guest bug so log it.

Signed-off-by: Dylan Reid <dgreid@fb.com>

2026-04-25 18:35:21 +00:00

..

src

virtio-devices: balloon: Clamp range to region before PUNCH_HOLE

2026-04-25 18:35:21 +00:00

build.rs

build: Add "fuzzing" as a valid cfg(..) attribute

2024-05-08 08:10:28 +00:00

Cargo.toml

virtio-devices: Add set_notifier() method to VirtioInterrupt

2026-03-18 09:25:27 +00:00