From e790d3b7bcfafd0c81a3a0bffb5a10486cd92333 Mon Sep 17 00:00:00 2001 From: Anatol Belski Date: Fri, 15 May 2026 01:28:10 +0200 Subject: [PATCH] vm-virtio: checked_descriptor: Add unit test for address overflow Submit a descriptor whose addr plus len would wrap around the u64 address space and verify CheckedDescriptorIter rejects it without panicking, with failed_addr returning the descriptor's address. Signed-off-by: Anatol Belski --- vm-virtio/src/checked_descriptor.rs | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/vm-virtio/src/checked_descriptor.rs b/vm-virtio/src/checked_descriptor.rs index 4d4f37e28..81409c6b6 100644 --- a/vm-virtio/src/checked_descriptor.rs +++ b/vm-virtio/src/checked_descriptor.rs @@ -377,4 +377,19 @@ mod unit_tests { let result = it.next().expect("must yield an item"); assert_eq!(result.unwrap_err(), GuestAddress(addr)); } + + #[test] + fn rejects_descriptor_with_address_overflow() { + // A descriptor whose addr plus len would wrap around the u64 address + // space must be rejected without panicking. + const MEM_SIZE: usize = 128 * 1024; + let addr = u64::MAX - 100; + let len: u32 = 1024; + let (_mem, mem_atomic, mut queue) = setup_vq(MEM_SIZE, addr, len, 0); + let mem_guard = mem_atomic.memory(); + let mut chain = queue.pop_descriptor_chain(mem_guard).unwrap(); + let mut it = chain.checked_iter(None); + let result = it.next().expect("must yield an item"); + assert_eq!(result.unwrap_err(), GuestAddress(addr)); + } }