Qian Cai <cai@xxxxxx> writes: >> On Apr 14, 2020, at 10:32 AM, Qian Cai <cai@xxxxxx> wrote: >> >> Fuzzers are unhappy. Thoughts? > > This is rather to reproduce. All the traces so far are from copy_from_user() to trigger a page fault, > and then it dereferences a bad pte in swap_vma_readahead(), > > for (i = 0, pte = ra_info.ptes; i < ra_info.nr_pte; > i++, pte++) { > pentry = *pte; <— crashed here. > if (pte_none(pentry)) Is it possible to bisect this? Because the crash point is identified, it may be helpful to collect and analyze the status of the faulting page table and readahead ptes. But I am not familiar with the ARM64 architecture. So I cannot help much here. Best Regards, Huang, Ying