In the Linux kernel, the following vulnerability has been resolved: dma-buf: heaps: Fix potential spectre v1 gadget It appears like nr could be a Spectre v1 gadget as it's supplied by a user and used as an array index. Prevent the contents of kernel memory from being leaked to userspace via speculative execution by using array_index_nospec. [sumits: added fixes and cc: stable tags]
The product behaves differently or sends different responses under different circumstances in a way that is observable to an unauthorized actor, which exposes security-relevant information about the state of the product, such as whether a particular operation was successful or not.