On Fri, Aug 30, 2024 at 1:05 AM syzbot <syzbot+e099d407346c45275ce9@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > syzbot found the following issue on: > > HEAD commit: 20371ba12063 Merge tag 'drm-fixes-2024-08-30' of https://g.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=107a8463980000 > kernel config: https://syzkaller.appspot.com/x/.config?x=6fafac02e339cc84 > dashboard link: https://syzkaller.appspot.com/bug?extid=e099d407346c45275ce9 > compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 > > Unfortunately, I don't have any reproducer for this issue yet. > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/4a8763df1c20/disk-20371ba1.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/f9678a905383/vmlinux-20371ba1.xz > kernel image: https://storage.googleapis.com/syzbot-assets/ef6e49adc393/bzImage-20371ba1.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+e099d407346c45275ce9@xxxxxxxxxxxxxxxxxxxxxxxxx > > ================================================================== > BUG: KCSAN: data-race in mem_cgroup_iter / mem_cgroup_iter +Kinsey Ho This looks relevant to the recent mem_cgroup_iter() changes. > > read-write to 0xffff888114b82668 of 4 bytes by task 5527 on cpu 1: > mem_cgroup_iter+0x28e/0x380 mm/memcontrol.c:1080 > shrink_node_memcgs mm/vmscan.c:5924 [inline] > shrink_node+0x74a/0x1d40 mm/vmscan.c:5948 > shrink_zones mm/vmscan.c:6192 [inline] > do_try_to_free_pages+0x3c6/0xc50 mm/vmscan.c:6254 > try_to_free_mem_cgroup_pages+0x1f3/0x4f0 mm/vmscan.c:6586 > try_charge_memcg+0x2bc/0x810 mm/memcontrol.c:2210 > try_charge mm/memcontrol-v1.h:20 [inline] > charge_memcg mm/memcontrol.c:4439 [inline] > mem_cgroup_swapin_charge_folio+0x107/0x1a0 mm/memcontrol.c:4524 > __read_swap_cache_async+0x2b7/0x520 mm/swap_state.c:516 > swap_cluster_readahead+0x276/0x3f0 mm/swap_state.c:680 > swapin_readahead+0xe4/0x760 mm/swap_state.c:882 > do_swap_page+0x3da/0x1ef0 mm/memory.c:4119 > handle_pte_fault mm/memory.c:5524 [inline] > __handle_mm_fault mm/memory.c:5664 [inline] > handle_mm_fault+0x8cb/0x2a30 mm/memory.c:5832 > do_user_addr_fault arch/x86/mm/fault.c:1338 [inline] > handle_page_fault arch/x86/mm/fault.c:1481 [inline] > exc_page_fault+0x3b9/0x650 arch/x86/mm/fault.c:1539 > asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 > > read to 0xffff888114b82668 of 4 bytes by task 5528 on cpu 0: > mem_cgroup_iter+0xba/0x380 mm/memcontrol.c:1018 > shrink_node_memcgs mm/vmscan.c:5869 [inline] > shrink_node+0x458/0x1d40 mm/vmscan.c:5948 > shrink_zones mm/vmscan.c:6192 [inline] > do_try_to_free_pages+0x3c6/0xc50 mm/vmscan.c:6254 > try_to_free_mem_cgroup_pages+0x1f3/0x4f0 mm/vmscan.c:6586 > try_charge_memcg+0x2bc/0x810 mm/memcontrol.c:2210 > try_charge mm/memcontrol-v1.h:20 [inline] > charge_memcg mm/memcontrol.c:4439 [inline] > mem_cgroup_swapin_charge_folio+0x107/0x1a0 mm/memcontrol.c:4524 > __read_swap_cache_async+0x2b7/0x520 mm/swap_state.c:516 > swap_cluster_readahead+0x276/0x3f0 mm/swap_state.c:680 > swapin_readahead+0xe4/0x760 mm/swap_state.c:882 > do_swap_page+0x3da/0x1ef0 mm/memory.c:4119 > handle_pte_fault mm/memory.c:5524 [inline] > __handle_mm_fault mm/memory.c:5664 [inline] > handle_mm_fault+0x8cb/0x2a30 mm/memory.c:5832 > do_user_addr_fault arch/x86/mm/fault.c:1389 [inline] > handle_page_fault arch/x86/mm/fault.c:1481 [inline] > exc_page_fault+0x296/0x650 arch/x86/mm/fault.c:1539 > asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 > __get_user_8+0x11/0x20 arch/x86/lib/getuser.S:94 > fetch_robust_entry kernel/futex/core.c:783 [inline] > exit_robust_list+0x31/0x280 kernel/futex/core.c:811 > futex_cleanup kernel/futex/core.c:1043 [inline] > futex_exit_release+0xe3/0x130 kernel/futex/core.c:1144 > exit_mm_release+0x1a/0x30 kernel/fork.c:1637 > exit_mm+0x38/0x190 kernel/exit.c:544 > do_exit+0x55e/0x1720 kernel/exit.c:869 > do_group_exit+0x102/0x150 kernel/exit.c:1031 > get_signal+0xf2f/0x1080 kernel/signal.c:2917 > arch_do_signal_or_restart+0x95/0x4b0 arch/x86/kernel/signal.c:310 > exit_to_user_mode_loop kernel/entry/common.c:111 [inline] > exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] > __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] > syscall_exit_to_user_mode+0x59/0x130 kernel/entry/common.c:218 > do_syscall_64+0xd6/0x1c0 arch/x86/entry/common.c:89 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > > value changed: 0x00000522 -> 0x00000528 > > Reported by Kernel Concurrency Sanitizer on: > CPU: 0 UID: 0 PID: 5528 Comm: syz.3.488 Not tainted 6.11.0-rc5-syzkaller-00176-g20371ba12063 #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 > ================================================================== > syz.3.488 (5528) used greatest stack depth: 9096 bytes left > > > --- > This report is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > > If the report is already addressed, let syzbot know by replying with: > #syz fix: exact-commit-title > > If you want to overwrite report's subsystems, reply with: > #syz set subsystems: new-subsystem > (See the list of subsystem names on the web dashboard) > > If the report is a duplicate of another one, reply with: > #syz dup: exact-subject-of-another-report > > If you want to undo deduplication, reply with: > #syz undup >