syzbot

BUG: Bad page state in process syz-executor  pfn:2cab6
page:ffffea0000b2ad80 refcount:0 mapcount:0 mapping:ffff88805e5287c8 index:0x2 pfn:0x2cab6
aops:z_erofs_cache_aops ino:0
flags: 0xfff00000000001(locked|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000001 dead000000000100 dead000000000122 ffff88805e5287c8
raw: 0000000000000002 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x192840(GFP_NOWAIT|__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5940, tgid 5940 (syz.0.16), ts 79974988843, free_ts 79527133842
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554
 prep_new_page mm/page_alloc.c:1561 [inline]
 get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191
 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457
 z_erofs_bind_cache fs/erofs/zdata.c:599 [inline]
 z_erofs_pcluster_begin fs/erofs/zdata.c:883 [inline]
 z_erofs_do_read_page+0x20c0/0x3680 fs/erofs/zdata.c:1018
 z_erofs_pcluster_readmore+0x2cf/0x450 fs/erofs/zdata.c:1818
 z_erofs_read_folio+0x208/0x540 fs/erofs/zdata.c:1838
 filemap_read_folio+0x167/0x760 mm/filemap.c:2420
 do_read_cache_folio+0x470/0x7e0 mm/filemap.c:3789
 erofs_bread+0x16f/0x630 fs/erofs/data.c:48
 erofs_find_target_block fs/erofs/namei.c:103 [inline]
 erofs_namei+0x28c/0xf00 fs/erofs/namei.c:177
 erofs_lookup+0x135/0x310 fs/erofs/namei.c:206
 __lookup_slow+0x281/0x3b0 fs/namei.c:1694
 lookup_slow+0x53/0x70 fs/namei.c:1711
 walk_component fs/namei.c:2002 [inline]
 link_path_walk+0x970/0xe00 fs/namei.c:2329
 path_parentat fs/namei.c:2530 [inline]
 __filename_parentat+0x205/0x610 fs/namei.c:2554
 filename_parentat fs/namei.c:2572 [inline]
 filename_create+0xd0/0x460 fs/namei.c:3863
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1154 [inline]
 free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336
 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429
 discard_slab mm/slub.c:2122 [inline]
 __unfreeze_partials+0x1cf/0x210 mm/slub.c:2662
 put_cpu_partial+0x17c/0x250 mm/slub.c:2738
 __slab_free+0x31d/0x410 mm/slub.c:3686
 qlink_free mm/kasan/quarantine.c:166 [inline]
 qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185
 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305
 kasan_slab_alloc include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767
 slab_alloc_node mm/slub.c:3485 [inline]
 __kmem_cache_alloc_node+0x13e/0x260 mm/slub.c:3524
 kmalloc_trace+0x2a/0xe0 mm/slab_common.c:1098
 kmalloc include/linux/slab.h:600 [inline]
 kzalloc include/linux/slab.h:721 [inline]
 ref_tracker_alloc+0x134/0x460 lib/ref_tracker.c:203
 __netns_tracker_alloc include/net/net_namespace.h:334 [inline]
 netlink_release+0x16b4/0x1ad0 net/netlink/af_netlink.c:808
 __sock_release net/socket.c:659 [inline]
 sock_release+0x7f/0x140 net/socket.c:687
 diag_net_exit+0x40/0x60 net/core/sock_diag.c:346
 ops_exit_list net/core/net_namespace.c:173 [inline]
 cleanup_net+0x6f4/0xb90 net/core/net_namespace.c:652
Modules linked in:
CPU: 0 PID: 5891 Comm: syz-executor Not tainted 6.6.100-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 bad_page+0x14b/0x170 mm/page_alloc.c:512
 free_page_is_bad mm/page_alloc.c:961 [inline]
 free_pages_prepare mm/page_alloc.c:1146 [inline]
 free_unref_page_prepare+0x887/0x8e0 mm/page_alloc.c:2336
 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429
 detach_page_private include/linux/pagemap.h:539 [inline]
 erofs_try_to_free_all_cached_pages+0x295/0x600 fs/erofs/zdata.c:651
 erofs_try_to_release_workgroup fs/erofs/utils.c:132 [inline]
 erofs_shrink_workstation+0x118/0x290 fs/erofs/utils.c:161
 erofs_shrinker_unregister+0x5d/0x170 fs/erofs/utils.c:198
 erofs_put_super+0x4e/0x150 fs/erofs/super.c:812
 generic_shutdown_super+0x134/0x2b0 fs/super.c:693
 kill_block_super+0x44/0x90 fs/super.c:1660
 erofs_kill_sb+0x4c/0x140 fs/erofs/super.c:794
 deactivate_locked_super+0x97/0x100 fs/super.c:481
 cleanup_mnt+0x429/0x4c0 fs/namespace.c:1250
 task_work_run+0x1ce/0x250 kernel/task_work.c:239
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f3b8878fcd7
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007fff514e8b38 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f3b88810b55 RCX: 00007f3b8878fcd7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff514e8bf0
RBP: 00007fff514e8bf0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff514e9c80
R13: 00007f3b88810b55 R14: 0000000000013862 R15: 00007fff514e9cc0
 </TASK>