> On Tue, Jul 25, 2023 at 11:57:22PM -0700, syzbot wrote: >> syzbot has bisected this issue to: > > FWIW, this is unrelated to the previous issue. It's the caller of > mas_walk() that has violated the locking constraints, and mas_walk() is > simply reporting the issue. Is there a way to get syzbot to understand > that it needs to unwind the call-stack further to decide who to blame? > >> commit a52f58b34afe095ebc5823684eb264404dad6f7b >> Author: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> >> Date: Mon Jul 24 18:54:10 2023 +0000 >> >> mm: handle faults that merely update the accessed bit under the VMA lock >> >> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1783585ea80000 >> start commit: [unknown] >> git tree: linux-next >> final oops: https://syzkaller.appspot.com/x/report.txt?x=1443585ea80000 >> console output: https://syzkaller.appspot.com/x/log.txt?x=1043585ea80000 >> kernel config: https://syzkaller.appspot.com/x/.config?x=f481ab36ce878b84 >> dashboard link: https://syzkaller.appspot.com/bug?extid=8645fe63c4d22c8d27b8 >> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1697cec9a80000 >> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1566986ea80000 > > #syz test want 2 args (repo, branch), got 4 > > diff --git a/mm/memory.c b/mm/memory.c > index 20a2e9ed4aeb..57b271108bdc 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -3567,6 +3567,12 @@ static vm_fault_t do_wp_page(struct vm_fault *vmf) > return 0; > } > copy: > + if ((vmf->flags & FAULT_FLAG_VMA_LOCK) && !vma->anon_vma) { > + pte_unmap_unlock(vmf->pte, vmf->ptl); > + vma_end_read(vmf->vma); > + return VM_FAULT_RETRY; > + } > + > /* > * Ok, we need to copy. Oh, well.. > */
