On Tue, 02 Apr 2024 13:10:29 -0700 syzbot <syzbot+58fc2a881f3b3df5e336@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 39cd87c4eb2b Linux 6.9-rc2 > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=129de21d180000 > kernel config: https://syzkaller.appspot.com/x/.config?x=d024e89f7bb376ce > dashboard link: https://syzkaller.appspot.com/bug?extid=58fc2a881f3b3df5e336 > 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/b9b2dcffd7d5/disk-39cd87c4.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/5f4981fa60e6/vmlinux-39cd87c4.xz > kernel image: https://storage.googleapis.com/syzbot-assets/691f671f70ad/bzImage-39cd87c4.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+58fc2a881f3b3df5e336@xxxxxxxxxxxxxxxxxxxxxxxxx > > ================================================================== > BUG: KCSAN: data-race in __delete_from_swap_cache / folio_mapping > > write to 0xffffea0004798fa8 of 8 bytes by task 29 on cpu 0: > __delete_from_swap_cache+0x1f2/0x290 mm/swap_state.c:161 folio->swap.val = 0; > delete_from_swap_cache+0x72/0xe0 mm/swap_state.c:241 > folio_free_swap+0x19f/0x1c0 mm/swapfile.c:1600 > free_swap_cache mm/swap_state.c:290 [inline] > free_pages_and_swap_cache+0x1d9/0x400 mm/swap_state.c:322 > __tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline] > tlb_batch_pages_flush mm/mmu_gather.c:149 [inline] > tlb_flush_mmu_free mm/mmu_gather.c:366 [inline] > tlb_flush_mmu+0x2cf/0x440 mm/mmu_gather.c:373 > tlb_finish_mmu+0x8c/0x100 mm/mmu_gather.c:465 > __oom_reap_task_mm+0x231/0x2e0 mm/oom_kill.c:553 > oom_reap_task_mm mm/oom_kill.c:589 [inline] > oom_reap_task mm/oom_kill.c:613 [inline] > oom_reaper+0x264/0x850 mm/oom_kill.c:654 > kthread+0x1d1/0x210 kernel/kthread.c:388 > ret_from_fork+0x4b/0x60 arch/x86/kernel/process.c:147 > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243 > > read to 0xffffea0004798fa8 of 8 bytes by task 14567 on cpu 1: > folio_mapping+0xd2/0x110 mm/util.c:797 return swap_address_space(folio->swap); > folio_evictable mm/internal.h:256 [inline] > move_folios_to_lru+0x137/0x690 mm/vmscan.c:1808 > shrink_inactive_list mm/vmscan.c:1929 [inline] > shrink_list mm/vmscan.c:2163 [inline] > shrink_lruvec+0xbd8/0x1640 mm/vmscan.c:5687 > shrink_node_memcgs mm/vmscan.c:5873 [inline] > shrink_node+0xa78/0x15a0 mm/vmscan.c:5908 > shrink_zones mm/vmscan.c:6152 [inline] > do_try_to_free_pages+0x3cc/0xca0 mm/vmscan.c:6214 > > ... > These both point at David's 3d2c90876887 ("mm/swap: inline folio_set_swap_entry() and folio_swap_entry()") which is probably innocent, but I have to blame someone ;)
