================================================================== BUG: KASAN: use-after-free in nilfs_segctor_confirm+0x175/0x190 fs/nilfs2/segment.c:837 Read of size 8 at addr ffff8880a3ab5630 by task syz-executor.5/3639 CPU: 1 PID: 3639 Comm: syz-executor.5 Not tainted 6.0.0-syzkaller-09589-g55be6084c8e0 #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+0xcd/0x134 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:317 [inline] print_report.cold+0x2ba/0x719 mm/kasan/report.c:433 kasan_report+0xb1/0x1e0 mm/kasan/report.c:495 nilfs_segctor_confirm+0x175/0x190 fs/nilfs2/segment.c:837 nilfs_segctor_destroy fs/nilfs2/segment.c:2729 [inline] nilfs_detach_log_writer+0x856/0x9f0 fs/nilfs2/segment.c:2810 nilfs_put_super+0x3f/0x1a0 fs/nilfs2/super.c:468 generic_shutdown_super+0x154/0x410 fs/super.c:491 kill_block_super+0x97/0xf0 fs/super.c:1427 deactivate_locked_super+0x94/0x160 fs/super.c:331 deactivate_super+0xad/0xd0 fs/super.c:362 cleanup_mnt+0x2ae/0x3d0 fs/namespace.c:1186 task_work_run+0xdd/0x1a0 kernel/task_work.c:177 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:169 [inline] exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:294 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f529c68ca17 Code: ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 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 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff78fb46c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f529c68ca17 RDX: 00007fff78fb479b RSI: 000000000000000a RDI: 00007fff78fb4790 RBP: 00007fff78fb4790 R08: 00000000ffffffff R09: 00007fff78fb4560 R10: 0000555556ade8db R11: 0000000000000246 R12: 00007f529c6e55f6 R13: 00007fff78fb5850 R14: 0000555556ade810 R15: 00007fff78fb5890 Allocated by task 22839: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:45 [inline] set_alloc_info mm/kasan/common.c:437 [inline] ____kasan_kmalloc mm/kasan/common.c:516 [inline] ____kasan_kmalloc mm/kasan/common.c:475 [inline] __kasan_kmalloc+0xa9/0xd0 mm/kasan/common.c:525 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:733 [inline] nilfs_find_or_create_root+0x84/0x4d0 fs/nilfs2/the_nilfs.c:747 nilfs_attach_checkpoint+0xc1/0x4b0 fs/nilfs2/super.c:519 nilfs_fill_super fs/nilfs2/super.c:1064 [inline] nilfs_mount+0xb12/0xfb0 fs/nilfs2/super.c:1317 legacy_get_tree+0x105/0x220 fs/fs_context.c:610 vfs_get_tree+0x89/0x2f0 fs/super.c:1530 do_new_mount fs/namespace.c:3040 [inline] path_mount+0x1326/0x1e20 fs/namespace.c:3370 do_mount fs/namespace.c:3383 [inline] __do_sys_mount fs/namespace.c:3591 [inline] __se_sys_mount fs/namespace.c:3568 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3568 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 3639: kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38 kasan_set_track+0x21/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:367 [inline] ____kasan_slab_free+0x166/0x1c0 mm/kasan/common.c:329 kasan_slab_free include/linux/kasan.h:200 [inline] slab_free_hook mm/slub.c:1759 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1785 slab_free mm/slub.c:3539 [inline] kfree+0xe2/0x580 mm/slub.c:4567 nilfs_put_root+0xb1/0xd0 fs/nilfs2/the_nilfs.c:804 nilfs_clear_inode+0x29a/0x330 fs/nilfs2/inode.c:895 nilfs_evict_inode+0x318/0x440 fs/nilfs2/inode.c:908 evict+0x2ed/0x6b0 fs/inode.c:664 dispose_list+0x117/0x1e0 fs/inode.c:697 evict_inodes+0x352/0x450 fs/inode.c:747 generic_shutdown_super+0xab/0x410 fs/super.c:479 kill_block_super+0x97/0xf0 fs/super.c:1427 deactivate_locked_super+0x94/0x160 fs/super.c:331 deactivate_super+0xad/0xd0 fs/super.c:362 cleanup_mnt+0x2ae/0x3d0 fs/namespace.c:1186 task_work_run+0xdd/0x1a0 kernel/task_work.c:177 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:169 [inline] exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:294 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff8880a3ab5600 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 48 bytes inside of 256-byte region [ffff8880a3ab5600, ffff8880a3ab5700) The buggy address belongs to the physical page: page:ffffea00028ead00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xa3ab4 head:ffffea00028ead00 order:1 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888011841b40 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 22808, tgid 22807 (syz-executor.3), ts 736886376334, free_ts 736854866769 prep_new_page mm/page_alloc.c:2532 [inline] get_page_from_freelist+0x109b/0x2ce0 mm/page_alloc.c:4283 __alloc_pages+0x1c7/0x510 mm/page_alloc.c:5549 alloc_pages+0x1a6/0x270 mm/mempolicy.c:2270 alloc_slab_page mm/slub.c:1829 [inline] allocate_slab+0x27e/0x3d0 mm/slub.c:1974 new_slab mm/slub.c:2034 [inline] ___slab_alloc+0x84f/0xe80 mm/slub.c:3036 __slab_alloc.constprop.0+0x4d/0xa0 mm/slub.c:3123 slab_alloc_node mm/slub.c:3214 [inline] slab_alloc mm/slub.c:3256 [inline] __kmalloc+0x32b/0x340 mm/slub.c:4425 kmalloc_array include/linux/slab.h:640 [inline] kcalloc include/linux/slab.h:671 [inline] iter_file_splice_write+0x168/0xc90 fs/splice.c:625 do_splice_from fs/splice.c:764 [inline] direct_splice_actor+0x110/0x180 fs/splice.c:931 splice_direct_to_actor+0x331/0x8a0 fs/splice.c:886 do_splice_direct+0x1a7/0x270 fs/splice.c:974 do_sendfile+0xb19/0x1270 fs/read_write.c:1255 __do_sys_sendfile64 fs/read_write.c:1323 [inline] __se_sys_sendfile64 fs/read_write.c:1309 [inline] __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1309 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 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+0x5e4/0xd20 mm/page_alloc.c:1499 free_unref_page_prepare mm/page_alloc.c:3380 [inline] free_unref_page+0x19/0x4d0 mm/page_alloc.c:3476 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2553 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0xa2/0xc0 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] slab_alloc mm/slub.c:3256 [inline] __kmem_cache_alloc_lru mm/slub.c:3263 [inline] kmem_cache_alloc+0x267/0x3b0 mm/slub.c:3273 nilfs_btree_alloc_path+0x3b/0x180 fs/nilfs2/btree.c:28 nilfs_btree_lookup_contig+0xab/0xb20 fs/nilfs2/btree.c:706 nilfs_bmap_lookup_contig+0x83/0x180 fs/nilfs2/bmap.c:92 nilfs_get_block+0x1ee/0xa50 fs/nilfs2/inode.c:85 __block_write_begin_int+0x3ca/0x1520 fs/buffer.c:2006 __block_write_begin fs/buffer.c:2056 [inline] block_write_begin+0xb5/0x4d0 fs/buffer.c:2117 nilfs_write_begin+0x9c/0x1a0 fs/nilfs2/inode.c:261 generic_perform_write+0x246/0x560 mm/filemap.c:3745 __generic_file_write_iter+0x398/0x4d0 mm/filemap.c:3841 Memory state around the buggy address: ffff8880a3ab5500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880a3ab5580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880a3ab5600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a3ab5680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a3ab5700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================