EXT4-fs (loop2): mounted filesystem without journal. Quota mode: none. EXT4-fs error (device loop2): ext4_validate_block_bitmap:438: comm syz.2.19: bg 0: block 465: padding at end of block bitmap is not set EXT4-fs (loop2): Remounting filesystem read-only ================================================================== BUG: KASAN: use-after-free in ext4_read_inline_data fs/ext4/inline.c:210 [inline] BUG: KASAN: use-after-free in ext4_inlinedir_to_tree+0x50c/0xff0 fs/ext4/inline.c:1412 Read of size 52 at addr ffff888129e36b97 by task syz.2.19/401 CPU: 1 PID: 401 Comm: syz.2.19 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:88 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106 print_address_description+0x71/0x200 mm/kasan/report.c:316 print_report+0x4a/0x60 mm/kasan/report.c:420 kasan_report+0x122/0x150 mm/kasan/report.c:524 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x249/0x2a0 mm/kasan/generic.c:189 memcpy+0x2d/0x70 mm/kasan/shadow.c:65 ext4_read_inline_data fs/ext4/inline.c:210 [inline] ext4_inlinedir_to_tree+0x50c/0xff0 fs/ext4/inline.c:1412 ext4_htree_fill_tree+0x508/0x1160 fs/ext4/namei.c:1211 ext4_dx_readdir fs/ext4/dir.c:608 [inline] ext4_readdir+0x2f80/0x3e10 fs/ext4/dir.c:145 iterate_dir+0x271/0x610 fs/readdir.c:-1 __do_sys_getdents fs/readdir.c:286 [inline] __se_sys_getdents+0xf2/0x250 fs/readdir.c:271 __x64_sys_getdents+0x7b/0x90 fs/readdir.c:271 x64_sys_call+0x212/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:79 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fa35b19ce59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffe86e85c18 EFLAGS: 00000246 ORIG_RAX: 000000000000004e RAX: ffffffffffffffda RBX: 00007fa35b415fa0 RCX: 00007fa35b19ce59 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00007fa35b232d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa35b415fac R14: 00007fa35b415fa0 R15: 00007fa35b415fa0 The buggy address belongs to the physical page: page:ffffea0004a78d80 refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x129e36 flags: 0x4000000000000000(zone=1) raw: 4000000000000000 ffffea0004a78dc8 ffffea0004a78d48 0000000000000000 raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 0, migratetype Movable, gfp_mask 0x140cca(GFP_HIGHUSER_MOVABLE|__GFP_COMP), pid 400, tgid 400 (syz.6.17), ts 28585355140, free_ts 28592985705 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2672 prep_new_page+0x1c/0x110 mm/page_alloc.c:2679 get_page_from_freelist+0x2d12/0x2d80 mm/page_alloc.c:4585 __alloc_pages+0x1fa/0x610 mm/page_alloc.c:5929 __folio_alloc+0x12/0x40 mm/page_alloc.c:5962 __folio_alloc_node include/linux/gfp.h:245 [inline] folio_alloc include/linux/gfp.h:274 [inline] shmem_alloc_folio mm/shmem.c:1597 [inline] shmem_alloc_and_acct_folio+0x6dd/0x8c0 mm/shmem.c:1622 shmem_get_folio_gfp+0x119f/0x2230 mm/shmem.c:1951 shmem_get_folio mm/shmem.c:2082 [inline] shmem_write_begin+0xea/0x2c0 mm/shmem.c:2567 generic_perform_write+0x32d/0x740 mm/filemap.c:3914 __generic_file_write_iter+0x17a/0x230 mm/filemap.c:4013 generic_file_write_iter+0xae/0x310 mm/filemap.c:4042 call_write_iter include/linux/fs.h:2282 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x603/0xce0 fs/read_write.c:584 ksys_write+0x149/0x250 fs/read_write.c:637 __do_sys_write fs/read_write.c:649 [inline] __se_sys_write fs/read_write.c:646 [inline] __x64_sys_write+0x7b/0x90 fs/read_write.c:646 x64_sys_call+0x27b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:2 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1580 [inline] free_pcp_prepare mm/page_alloc.c:1654 [inline] free_unref_page_prepare+0x7f8/0x800 mm/page_alloc.c:3620 free_unref_page_list+0x117/0x8c0 mm/page_alloc.c:3771 release_pages+0xc93/0xcf0 mm/swap.c:1053 __pagevec_release+0x71/0xe0 mm/swap.c:1073 pagevec_release include/linux/pagevec.h:71 [inline] folio_batch_release include/linux/pagevec.h:135 [inline] shmem_undo_range+0x574/0x1540 mm/shmem.c:951 shmem_truncate_range mm/shmem.c:1067 [inline] shmem_evict_inode+0x255/0xa50 mm/shmem.c:1176 evict+0x4d7/0x8f0 fs/inode.c:708 iput_final fs/inode.c:1844 [inline] iput+0x620/0x670 fs/inode.c:1870 dentry_unlink_inode+0x33d/0x3f0 fs/dcache.c:405 __dentry_kill+0x460/0x670 fs/dcache.c:611 dentry_kill+0xc0/0x2a0 fs/dcache.c:-1 dput+0x42/0x80 fs/dcache.c:918 __fput+0x5be/0x8f0 fs/file_table.c:328 ____fput+0x15/0x20 fs/file_table.c:348 task_work_run+0x1e1/0x250 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0x9b/0xb0 kernel/entry/common.c:177 Memory state around the buggy address: ffff888129e36a80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888129e36b00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff888129e36b80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff888129e36c00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888129e36c80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ================================================================== EXT4-fs error (device loop2): ext4_inlinedir_to_tree:1450: inode #12: block 7: comm syz.2.19: path /0/file1/file0: bad entry in directory: rec_len % 4 != 0 - offset=35110, inode=3517778242, rec_len=35106, size=112 fake=0 EXT4-fs (loop2): Remounting filesystem read-only