On 10/28/22 22:15, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 247f34f7b803 Linux 6.1-rc2 > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=14a9efd2880000 > kernel config: https://syzkaller.appspot.com/x/.config?x=a66c6c673fb555e8 > dashboard link: https://syzkaller.appspot.com/bug?extid=f0b97304ef90f0d0b1dc > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=112217b4880000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=105f4616880000 > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/de212436b09b/disk-247f34f7.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/63c4feda220f/vmlinux-247f34f7.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+f0b97304ef90f0d0b1dc@xxxxxxxxxxxxxxxxxxxxxxxxx > > ------------[ cut here ]------------ > WARNING: CPU: 1 PID: 3612 at mm/hugetlb.c:5313 hugetlb_wp+0x20a/0x1af0 mm/hugetlb.c:5313 This warning was added with commit 1d8d14641fd94 ("mm/hugetlb: support write-faults in shared mappings"). It is there 'by design' as this this specific type of write fault is not supported. /* * hugetlb does not support FOLL_FORCE-style write faults that keep the * PTE mapped R/O such as maybe_mkwrite() would do. */ if (WARN_ON_ONCE(!unshare && !(vma->vm_flags & VM_WRITE))) return VM_FAULT_SIGSEGV; If there is an actual use case for this support, we can look at adding it. -- Mike Kravetz
