================================================================== BUG: KASAN: use-after-free in crc_itu_t+0x21c/0x2a0 lib/crc-itu-t.c:60 Read of size 1 at addr ffff888081cd4000 by task syz-executor.2/10993 CPU: 0 PID: 10993 Comm: syz-executor.2 Not tainted 6.3.0-syzkaller-11025-g89d77f71f493 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:351 [inline] print_report+0x163/0x540 mm/kasan/report.c:462 kasan_report+0x176/0x1b0 mm/kasan/report.c:572 crc_itu_t+0x21c/0x2a0 lib/crc-itu-t.c:60 udf_finalize_lvid fs/udf/super.c:1988 [inline] udf_sync_fs+0x1d2/0x380 fs/udf/super.c:2344 sync_filesystem+0xec/0x220 fs/sync.c:56 generic_shutdown_super+0x6f/0x340 fs/super.c:473 kill_block_super+0x84/0xf0 fs/super.c:1407 deactivate_locked_super+0xa4/0x110 fs/super.c:331 cleanup_mnt+0x426/0x4c0 fs/namespace.c:1177 task_work_run+0x24a/0x300 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xd9/0x100 kernel/entry/common.c:171 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x64/0x280 kernel/entry/common.c:297 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f07a4a8d5d7 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:00007fff45370778 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f07a4a8d5d7 RDX: 00007fff4537084c RSI: 000000000000000a RDI: 00007fff45370840 RBP: 00007fff45370840 R08: 00000000ffffffff R09: 00007fff45370610 R10: 0000555557217893 R11: 0000000000000246 R12: 00007f07a4ae6cdc R13: 00007fff45371900 R14: 0000555557217810 R15: 00007fff45371940 The buggy address belongs to the physical page: page:ffffea0002073500 refcount:1 mapcount:0 mapping:ffff888076f8db50 index:0x20b pfn:0x81cd4 memcg:ffff88802a49a000 aops:shmem_aops ino:1914 dentry name:"memfd:syzkaller" flags: 0xfff0000008001e(referenced|uptodate|dirty|lru|swapbacked|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff0000008001e ffffea0000fe93c8 ffffea0002073548 ffff888076f8db50 raw: 000000000000020b 0000000000000000 00000001ffffffff ffff88802a49a000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Movable, gfp_mask 0x140cca(GFP_HIGHUSER_MOVABLE|__GFP_COMP), pid 18061, tgid 18058 (syz-executor.1), ts 2118310855683, free_ts 2115972172492 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1e6/0x210 mm/page_alloc.c:1722 prep_new_page mm/page_alloc.c:1729 [inline] get_page_from_freelist+0x321c/0x33a0 mm/page_alloc.c:3493 __alloc_pages+0x255/0x670 mm/page_alloc.c:4759 __folio_alloc+0x13/0x30 mm/page_alloc.c:4791 vma_alloc_folio+0x48a/0x9a0 mm/mempolicy.c:2238 shmem_alloc_folio mm/shmem.c:1579 [inline] shmem_alloc_and_acct_folio+0x5e7/0xe10 mm/shmem.c:1603 shmem_get_folio_gfp+0x120f/0x3470 mm/shmem.c:1948 shmem_get_folio mm/shmem.c:2079 [inline] shmem_write_begin+0x172/0x4e0 mm/shmem.c:2573 generic_perform_write+0x300/0x5e0 mm/filemap.c:3923 __generic_file_write_iter+0x17a/0x400 mm/filemap.c:4051 generic_file_write_iter+0xaf/0x310 mm/filemap.c:4083 call_write_iter include/linux/fs.h:1854 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x7ec/0xc10 fs/read_write.c:584 ksys_write+0x1a0/0x2c0 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 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:1302 [inline] free_unref_page_prepare+0x903/0xa30 mm/page_alloc.c:2555 free_unref_page_list+0x596/0x830 mm/page_alloc.c:2696 release_pages+0x2193/0x2470 mm/swap.c:1042 __pagevec_release+0x84/0x100 mm/swap.c:1062 pagevec_release include/linux/pagevec.h:63 [inline] folio_batch_release include/linux/pagevec.h:132 [inline] shmem_undo_range+0x6af/0x1ba0 mm/shmem.c:954 shmem_truncate_range mm/shmem.c:1049 [inline] shmem_evict_inode+0x258/0x9f0 mm/shmem.c:1164 evict+0x2a4/0x620 fs/inode.c:665 __dentry_kill+0x436/0x650 fs/dcache.c:607 dentry_kill+0xbb/0x290 dput+0x1f3/0x420 fs/dcache.c:913 __fput+0x5e4/0x890 fs/file_table.c:329 task_work_run+0x24a/0x300 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xd9/0x100 kernel/entry/common.c:171 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x64/0x280 kernel/entry/common.c:297 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86 Memory state around the buggy address: ffff888081cd3f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888081cd3f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888081cd4000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ^ ffff888081cd4080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888081cd4100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================