On Wed, 15 Nov 2023 05:32:19 -0800 syzbot <syzbot+7ca4b2719dc742b8d0a4@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: ac347a0655db Merge tag 'arm64-fixes' of git://git.kernel.o.. > git tree: upstream > console+strace: https://syzkaller.appspot.com/x/log.txt?x=15ff3057680000 > kernel config: https://syzkaller.appspot.com/x/.config?x=287570229f5c0a7c > dashboard link: https://syzkaller.appspot.com/bug?extid=7ca4b2719dc742b8d0a4 > compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=162a25ff680000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13d62338e80000 > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/00e30e1a5133/disk-ac347a06.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/07c43bc37935/vmlinux-ac347a06.xz > kernel image: https://storage.googleapis.com/syzbot-assets/c6690c715398/bzImage-ac347a06.xz > > The issue was bisected to: > > commit 12f6b01a0bcbeeab8cc9305673314adb3adf80f7 > Author: Muhammad Usama Anjum <usama.anjum@xxxxxxxxxxxxx> > Date: Mon Aug 21 14:15:15 2023 +0000 > > fs/proc/task_mmu: add fast paths to get/clear PAGE_IS_WRITTEN flag Thanks. The bisection is surprising, but the mentioned patch does mess with pagemap. How about we add this? From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Subject: mm/memory.c:zap_pte_range() print bad swap entry Date: Wed Nov 15 01:54:18 PM PST 2023 We have a report of this WARN() triggering. Let's print the offending swp_entry_t to help diagnosis. Link: https://lkml.kernel.org/r/000000000000b0e576060a30ee3b@xxxxxxxxxx Cc: Muhammad Usama Anjum <usama.anjum@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memory.c | 1 + 1 file changed, 1 insertion(+) --- a/mm/memory.c~a +++ a/mm/memory.c @@ -1521,6 +1521,7 @@ static unsigned long zap_pte_range(struc continue; } else { /* We should have covered all the swap entry types */ + pr_alert("unrecognized swap entry 0x%lx\n", entry.val); WARN_ON_ONCE(1); } pte_clear_not_present_full(mm, addr, pte, tlb->fullmm); _
