On Sun, 23 Oct 2022 at 19:22, Mike Kravetz <mike.kravetz@xxxxxxxxxx> wrote: > > On 10/23/22 00:26, syzbot wrote: > > Hello, > > > > syzbot found the following issue on: > > > > HEAD commit: bb1a1146467a Merge tag 'cgroup-for-6.1-rc1-fixes' of git:/.. > > git tree: upstream > > console output: https://syzkaller.appspot.com/x/log.txt?x=15f38cc2880000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=972ee691c428ae39 > > dashboard link: https://syzkaller.appspot.com/bug?extid=1b27d7a2722eabc2c5d5 > > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 > > > > Unfortunately, I don't have any reproducer for this issue yet. > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > Reported-by: syzbot+1b27d7a2722eabc2c5d5@xxxxxxxxxxxxxxxxxxxxxxxxx > > > > ================================================================== > > BUG: KASAN: use-after-free in instrument_atomic_read include/linux/instrumented.h:72 [inline] > > BUG: KASAN: use-after-free in atomic_long_read include/linux/atomic/atomic-instrumented.h:1265 [inline] > > BUG: KASAN: use-after-free in is_rwsem_reader_owned kernel/locking/rwsem.c:193 [inline] > > BUG: KASAN: use-after-free in __down_read_common kernel/locking/rwsem.c:1262 [inline] > > BUG: KASAN: use-after-free in __down_read_common kernel/locking/rwsem.c:1255 [inline] > > BUG: KASAN: use-after-free in __down_read kernel/locking/rwsem.c:1269 [inline] > > BUG: KASAN: use-after-free in down_read+0x1d3/0x450 kernel/locking/rwsem.c:1511 > > Read of size 8 at addr ffff88801eabdc08 by task syz-executor.2/4171 > > > > CPU: 0 PID: 4171 Comm: syz-executor.2 Not tainted 6.1.0-rc1-syzkaller-00010-gbb1a1146467a #0 > > Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014 > > Call Trace: > > <TASK> > > __dump_stack lib/dump_stack.c:88 [inline] > > dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 > > print_address_description mm/kasan/report.c:284 [inline] > > print_report+0x15e/0x461 mm/kasan/report.c:395 > > kasan_report+0xbb/0x1f0 mm/kasan/report.c:495 > > check_region_inline mm/kasan/generic.c:183 [inline] > > kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189 > > instrument_atomic_read include/linux/instrumented.h:72 [inline] > > atomic_long_read include/linux/atomic/atomic-instrumented.h:1265 [inline] > > is_rwsem_reader_owned kernel/locking/rwsem.c:193 [inline] > > __down_read_common kernel/locking/rwsem.c:1262 [inline] > > __down_read_common kernel/locking/rwsem.c:1255 [inline] > > __down_read kernel/locking/rwsem.c:1269 [inline] > > down_read+0x1d3/0x450 kernel/locking/rwsem.c:1511 > > hugetlb_vma_lock_read mm/hugetlb.c:6797 [inline] > > hugetlb_fault+0x40a/0x2060 mm/hugetlb.c:5840 > > follow_hugetlb_page+0x3f3/0x1850 mm/hugetlb.c:6282 > > __get_user_pages+0x2cb/0xf10 mm/gup.c:1202 > > populate_vma_page_range+0x23d/0x320 mm/gup.c:1587 > > __mm_populate+0x101/0x3a0 mm/gup.c:1701 > > mm_populate include/linux/mm.h:2744 [inline] > > vm_mmap_pgoff+0x1fd/0x270 mm/util.c:525 > > ksys_mmap_pgoff+0x1c3/0x5a0 mm/mmap.c:1457 > > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > > do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 > > entry_SYSCALL_64_after_hwframe+0x63/0xcd > > RIP: 0033:0x7f07e488b5a9 > > Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 > > RSP: 002b:00007f07e59e7168 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 > > RAX: ffffffffffffffda RBX: 00007f07e49abf80 RCX: 00007f07e488b5a9 > > RDX: 0000000000000003 RSI: 0000000000b36000 RDI: 0000000020000000 > > RBP: 00007f07e48e6580 R08: ffffffffffffffff R09: 0000000000000000 > > R10: 0000000000068831 R11: 0000000000000246 R12: 0000000000000000 > > R13: 00007ffc053fba9f R14: 00007f07e59e7300 R15: 0000000000022000 > > </TASK> > > > > Allocated by task 4171: > > kasan_save_stack+0x1e/0x40 mm/kasan/common.c:45 > > kasan_set_track+0x21/0x30 mm/kasan/common.c:52 > > ____kasan_kmalloc mm/kasan/common.c:371 [inline] > > ____kasan_kmalloc mm/kasan/common.c:330 [inline] > > __kasan_kmalloc+0x9f/0xb0 mm/kasan/common.c:380 > > kmalloc include/linux/slab.h:576 [inline] > > hugetlb_vma_lock_alloc.part.0+0x3f/0x130 mm/hugetlb.c:6907 > > hugetlb_vma_lock_alloc mm/hugetlb.c:6663 [inline] > > hugetlb_reserve_pages+0xa3f/0xe80 mm/hugetlb.c:6532 > > hugetlbfs_file_mmap+0x40c/0x5c0 fs/hugetlbfs/inode.c:167 > > call_mmap include/linux/fs.h:2196 [inline] > > mmap_region+0x6bf/0x1bf0 mm/mmap.c:2624 > > do_mmap+0x825/0xf50 mm/mmap.c:1411 > > vm_mmap_pgoff+0x1ab/0x270 mm/util.c:520 > > ksys_mmap_pgoff+0x1c3/0x5a0 mm/mmap.c:1457 > > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > > do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 > > entry_SYSCALL_64_after_hwframe+0x63/0xcd > > > > Freed by task 4172: > > kasan_save_stack+0x1e/0x40 mm/kasan/common.c:45 > > kasan_set_track+0x21/0x30 mm/kasan/common.c:52 > > kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:511 > > ____kasan_slab_free mm/kasan/common.c:236 [inline] > > ____kasan_slab_free+0x13b/0x1a0 mm/kasan/common.c:200 > > kasan_slab_free include/linux/kasan.h:177 [inline] > > __cache_free mm/slab.c:3389 [inline] > > __do_kmem_cache_free mm/slab.c:3585 [inline] > > __kmem_cache_free+0xc9/0x3a0 mm/slab.c:3592 > > hugetlb_vma_lock_release mm/hugetlb.c:6852 [inline] > > kref_put include/linux/kref.h:65 [inline] > > __hugetlb_vma_unlock_write_put mm/hugetlb.c:6867 [inline] > > __hugetlb_vma_unlock_write_free mm/hugetlb.c:6875 [inline] > > __unmap_hugepage_range_final+0x2ad/0x340 mm/hugetlb.c:5196 > > unmap_single_vma+0x23d/0x2a0 mm/memory.c:1690 > > zap_page_range+0x38a/0x520 mm/memory.c:1762 > > madvise_dontneed_single_vma mm/madvise.c:793 [inline] > > madvise_dontneed_free mm/madvise.c:876 [inline] > > madvise_vma_behavior+0xee8/0x1cc0 mm/madvise.c:1015 > > madvise_walk_vmas+0x1c7/0x2b0 mm/madvise.c:1240 > > do_madvise.part.0+0x24a/0x340 mm/madvise.c:1419 > > do_madvise mm/madvise.c:1432 [inline] > > __do_sys_madvise mm/madvise.c:1432 [inline] > > __se_sys_madvise mm/madvise.c:1430 [inline] > > __x64_sys_madvise+0x113/0x150 mm/madvise.c:1430 > > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > > do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 > > entry_SYSCALL_64_after_hwframe+0x63/0xcd > > Looks like page fault is racing with the vma_lock freeing in > __unmap_hugepage_range_final as the result of a madvise(MADV_DONTNEED). > > It should be addressed with, > https://lore.kernel.org/linux-mm/20221023025047.470646-1-mike.kravetz@xxxxxxxxxx/ Let's tell syzbot so that it reports similar issues in future: #syz fix: hugetlb: don't delete vma_lock in hugetlb MADV_DONTNEED processing
