6.12-stable review patch. If anyone has any objections, please let me know.
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From: Danilo Krummrich dakr@kernel.org
[ Upstream commit fb1bf1067de979c89ae33589e0466d6ce0dde204 ]
When setting a new length, we have to justify that the set length represents the exact number of elements stored in the vector.
Reviewed-by: Benno Lossin benno.lossin@proton.me Reported-by: Alice Ryhl aliceryhl@google.com Closes: https://lore.kernel.org/rust-for-linux/20250311-iov-iter-v1-4-f6c9134ea824@g... Fixes: 2aac4cd7dae3 ("rust: alloc: implement kernel `Vec` type") Link: https://lore.kernel.org/r/20250315154436.65065-2-dakr@kernel.org Signed-off-by: Danilo Krummrich dakr@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- rust/kernel/alloc/kvec.rs | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/rust/kernel/alloc/kvec.rs b/rust/kernel/alloc/kvec.rs index 87a71fd40c3ca..f62204fe563f5 100644 --- a/rust/kernel/alloc/kvec.rs +++ b/rust/kernel/alloc/kvec.rs @@ -196,6 +196,9 @@ where #[inline] pub unsafe fn set_len(&mut self, new_len: usize) { debug_assert!(new_len <= self.capacity()); + + // INVARIANT: By the safety requirements of this method `new_len` represents the exact + // number of elements stored within `self`. self.len = new_len; }