================================================================== BUG: KASAN: use-after-free in nilfs_test_metadata_dirty+0x39/0x210 fs/nilfs2/segment.c:813 Read of size 8 at addr ffff888077725430 by task segctord/6971 CPU: 0 PID: 6971 Comm: segctord Not tainted 6.0.0-syzkaller-09423-g493ffd6605b2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1b1/0x28e lib/dump_stack.c:106 print_address_description+0x65/0x4b0 mm/kasan/report.c:317 print_report+0x108/0x1f0 mm/kasan/report.c:433 kasan_report+0xc3/0xf0 mm/kasan/report.c:495 nilfs_test_metadata_dirty+0x39/0x210 fs/nilfs2/segment.c:813 nilfs_segctor_confirm+0x78/0x2d0 fs/nilfs2/segment.c:837 nilfs_segctor_construct+0x122/0x8d0 fs/nilfs2/segment.c:2374 nilfs_segctor_thread_construct fs/nilfs2/segment.c:2483 [inline] nilfs_segctor_thread+0x534/0x1180 fs/nilfs2/segment.c:2566 kthread+0x266/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Allocated by task 6966: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:437 [inline] ____kasan_kmalloc+0xcd/0x100 mm/kasan/common.c:516 kasan_kmalloc include/linux/kasan.h:234 [inline] kmem_cache_alloc_trace+0x97/0x310 mm/slub.c:3289 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:733 [inline] nilfs_find_or_create_root+0x142/0x4f0 fs/nilfs2/the_nilfs.c:747 nilfs_attach_checkpoint+0xcd/0x4a0 fs/nilfs2/super.c:519 nilfs_fill_super+0x2e8/0x5d0 fs/nilfs2/super.c:1064 nilfs_mount+0x613/0x9b0 fs/nilfs2/super.c:1317 legacy_get_tree+0xea/0x180 fs/fs_context.c:610 vfs_get_tree+0x88/0x270 fs/super.c:1530 do_new_mount+0x289/0xad0 fs/namespace.c:3040 do_mount fs/namespace.c:3383 [inline] __do_sys_mount fs/namespace.c:3591 [inline] __se_sys_mount+0x2d3/0x3c0 fs/namespace.c:3568 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 6966: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x3d/0x60 mm/kasan/common.c:45 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:370 ____kasan_slab_free+0xd8/0x120 mm/kasan/common.c:367 kasan_slab_free include/linux/kasan.h:200 [inline] slab_free_hook mm/slub.c:1759 [inline] slab_free_freelist_hook+0x12e/0x1a0 mm/slub.c:1785 slab_free mm/slub.c:3539 [inline] kfree+0xda/0x210 mm/slub.c:4567 nilfs_evict_inode+0x253/0x3d0 fs/nilfs2/inode.c:924 evict+0x2a4/0x620 fs/inode.c:664 nilfs_new_inode+0x6b8/0x8a0 nilfs_create+0xdc/0x2d0 fs/nilfs2/namei.c:85 lookup_open fs/namei.c:3413 [inline] open_last_lookups fs/namei.c:3481 [inline] path_openat+0x12d0/0x2df0 fs/namei.c:3688 do_filp_open+0x264/0x4f0 fs/namei.c:3718 do_sys_openat2+0x124/0x4e0 fs/open.c:1310 do_sys_open fs/open.c:1326 [inline] __do_sys_openat fs/open.c:1342 [inline] __se_sys_openat fs/open.c:1337 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1337 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff888077725400 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 48 bytes inside of 256-byte region [ffff888077725400, ffff888077725500) The buggy address belongs to the physical page: page:ffffea0001ddc900 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x77724 head:ffffea0001ddc900 order:1 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001db8a80 dead000000000006 ffff888012041b40 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 3963, tgid 3952 (syz-executor.3), ts 219926161811, free_ts 132978042546 prep_new_page mm/page_alloc.c:2532 [inline] get_page_from_freelist+0x742/0x7c0 mm/page_alloc.c:4283 __alloc_pages+0x259/0x560 mm/page_alloc.c:5549 alloc_slab_page+0x70/0xf0 mm/slub.c:1829 allocate_slab+0x5e/0x520 mm/slub.c:1974 new_slab mm/slub.c:2034 [inline] ___slab_alloc+0x3ee/0xc40 mm/slub.c:3036 __slab_alloc mm/slub.c:3123 [inline] slab_alloc_node mm/slub.c:3214 [inline] slab_alloc mm/slub.c:3256 [inline] kmem_cache_alloc_trace+0x25f/0x310 mm/slub.c:3287 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:733 [inline] simple_attr_open+0x5e/0x170 fs/libfs.c:935 open_proxy_open+0x2b3/0x470 fs/debugfs/file.c:197 do_dentry_open+0x85f/0x11b0 fs/open.c:882 do_open fs/namei.c:3557 [inline] path_openat+0x25fc/0x2df0 fs/namei.c:3691 do_filp_open+0x264/0x4f0 fs/namei.c:3718 do_sys_openat2+0x124/0x4e0 fs/open.c:1310 do_sys_open fs/open.c:1326 [inline] __do_sys_openat fs/open.c:1342 [inline] __se_sys_openat fs/open.c:1337 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1337 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1449 [inline] free_pcp_prepare+0x812/0x900 mm/page_alloc.c:1499 free_unref_page_prepare mm/page_alloc.c:3380 [inline] free_unref_page+0x7d/0x5f0 mm/page_alloc.c:3476 qlist_free_all+0x2b/0x70 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x169/0x180 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x2f/0xd0 mm/kasan/common.c:447 kasan_slab_alloc include/linux/kasan.h:224 [inline] slab_post_alloc_hook mm/slab.h:727 [inline] slab_alloc_node mm/slub.c:3248 [inline] kmem_cache_alloc_node+0x1cc/0x350 mm/slub.c:3298 __alloc_skb+0xcf/0x2b0 net/core/skbuff.c:497 alloc_skb_fclone include/linux/skbuff.h:1315 [inline] tcp_stream_alloc_skb+0x3c/0x300 net/ipv4/tcp.c:861 tcp_sendmsg_locked+0xd70/0x40c0 net/ipv4/tcp.c:1324 tcp_sendmsg+0x2c/0x40 net/ipv4/tcp.c:1482 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg net/socket.c:734 [inline] sock_write_iter+0x3d4/0x540 net/socket.c:1108 call_write_iter include/linux/fs.h:2190 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x7dc/0xc50 fs/read_write.c:584 ksys_write+0x177/0x2a0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Memory state around the buggy address: ffff888077725300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888077725380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888077725400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888077725480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888077725500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================