6.12-stable review patch. If anyone has any objections, please let me know.
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From: Asahi Lina lina@asahilina.net
commit b7ed2b6f4e8d7f64649795e76ee9db67300de8eb upstream.
We were accidentally allocating a layout for the *square* of the object size due to a variable shadowing mishap.
Fixes memory bloat and page allocation failures in drm/asahi.
Reported-by: Janne Grunau j@jannau.net Fixes: 9e7bbfa18276 ("rust: alloc: introduce `ArrayLayout`") Signed-off-by: Asahi Lina lina@asahilina.net Acked-by: Danilo Krummrich dakr@kernel.org Reviewed-by: Neal Gompa neal@gompa.dev Link: https://lore.kernel.org/r/20241123-rust-fix-arraylayout-v1-1-197e64c95bd4@as... Signed-off-by: Miguel Ojeda ojeda@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- rust/kernel/alloc/layout.rs | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/rust/kernel/alloc/layout.rs +++ b/rust/kernel/alloc/layout.rs @@ -45,7 +45,7 @@ impl<T> ArrayLayout<T> { /// When `len * size_of::<T>()` overflows or when `len * size_of::<T>() > isize::MAX`. pub const fn new(len: usize) -> Result<Self, LayoutError> { match len.checked_mul(core::mem::size_of::<T>()) { - Some(len) if len <= ISIZE_MAX => { + Some(size) if size <= ISIZE_MAX => { // INVARIANT: We checked above that `len * size_of::<T>() <= isize::MAX`. Ok(Self { len,