Re: [PATCH] events: Reuse value read using READ_ONCE instead of re-reading it

On Mon, Sep 06, 2021 at 11:53:10AM +1000, Baptiste Lepers wrote:

In perf_event_addr_filters_apply, the task associated with
the event (event->ctx->task) is read using READ_ONCE at the beginning
of the function, checked, and then re-read from event->ctx->task,
voiding all guarantees of the checks. Reuse the value that was read by
READ_ONCE to ensure the consistency of the task struct throughout the
function.

Signed-off-by: Baptiste Lepers <redacted>
Fixes: 375637bc52495 ("perf/core: Introduce address range filtering")

Thanks!