On Mon, Sep 23, 2024, at 19:34, Lorenzo Stoakes wrote: > On Mon, Sep 23, 2024 at 11:56:06AM GMT, Shakeel Butt wrote: > > + /* Require PTRACE_MODE_READ to avoid leaking ASLR metadata. */ > + mm = mm_access(task, PTRACE_MODE_READ_FSCREDS); > + if (IS_ERR_OR_NULL(mm)) { > + ret = IS_ERR(mm) ? PTR_ERR(mm) : -ESRCH; > + goto release_task; > + } Any chance we can fix mm_access() to not be able to return a NULL pointer and an error pointer? IS_ERR_OR_NULL() is usually an indication of a confusing API, and this is clearly one of them, given that only one of the callers actually wants the NULL value instead of -ESRCH. Arnd