EXT4-fs (loop2): mounted filesystem without journal. Opts: errors=remount-ro,
EXT4-fs error (device loop2): ext4_validate_block_bitmap:438: comm syz.2.18: 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:209 [inline]
BUG: KASAN: use-after-free in ext4_inlinedir_to_tree+0x5f6/0xfd0 fs/ext4/inline.c:1419
Read of size 52 at addr ffff888110b1f05f by task syz.2.18/483

CPU: 0 PID: 483 Comm: syz.2.18 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 __dump_stack+0x21/0x24 lib/dump_stack.c:77
 dump_stack_lvl+0x1a7/0x208 lib/dump_stack.c:118
 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:435 [inline]
 kasan_report+0xe2/0x130 mm/kasan/report.c:452
 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:209 [inline]
 ext4_inlinedir_to_tree+0x5f6/0xfd0 fs/ext4/inline.c:1419
 ext4_htree_fill_tree+0x508/0x1160 fs/ext4/namei.c:1186
 ext4_dx_readdir fs/ext4/dir.c:601 [inline]
 ext4_readdir+0x2c49/0x3ab0 fs/ext4/dir.c:145
 iterate_dir+0x260/0x570 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
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f11b7821cb9
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:00007f11b7686028 EFLAGS: 00000246 ORIG_RAX: 000000000000004e
RAX: ffffffffffffffda RBX: 00007f11b7a9cfa0 RCX: 00007f11b7821cb9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 00007f11b788fbf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f11b7a9d038 R14: 00007f11b7a9cfa0 R15: 00007ffec5416968

Allocated by task 422:
 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:430 [inline]
 __kasan_slab_alloc+0xbd/0xf0 mm/kasan/common.c:463
 kasan_slab_alloc include/linux/kasan.h:244 [inline]
 slab_post_alloc_hook+0x5d/0x2f0 mm/slab.h:580
 slab_alloc_node mm/slub.c:2952 [inline]
 slab_alloc mm/slub.c:2960 [inline]
 kmem_cache_alloc+0x162/0x2d0 mm/slub.c:2965
 kmem_cache_zalloc include/linux/slab.h:657 [inline]
 __kernfs_new_node+0xe3/0x6b0 fs/kernfs/dir.c:662
 kernfs_new_node+0x150/0x260 fs/kernfs/dir.c:739
 __kernfs_create_file+0x4e/0x270 fs/kernfs/file.c:987
 sysfs_add_file_mode_ns+0x29a/0x350 fs/sysfs/file.c:306
 create_files fs/sysfs/group.c:64 [inline]
 internal_create_group+0x495/0xd00 fs/sysfs/group.c:149
 internal_create_groups fs/sysfs/group.c:189 [inline]
 sysfs_create_groups+0x58/0x120 fs/sysfs/group.c:215
 device_add_groups drivers/base/core.c:2364 [inline]
 device_add_attrs+0x8c/0x430 drivers/base/core.c:2512
 device_add+0x504/0xbf0 drivers/base/core.c:3224
 netdev_register_kobject+0x1bc/0x360 net/core/net-sysfs.c:1997
 register_netdevice+0xdf0/0x13e0 net/core/dev.c:10056
 __ip_tunnel_create+0x2c7/0x390 net/ipv4/ip_tunnel.c:267
 ip_tunnel_init_net+0x2be/0x730 net/ipv4/ip_tunnel.c:1069
 ipip_init_net+0x29/0x30 net/ipv4/ipip.c:645
 ops_init+0x1ba/0x4a0 net/core/net_namespace.c:144
 setup_net+0x376/0xb60 net/core/net_namespace.c:345
 copy_net_ns+0x314/0x520 net/core/net_namespace.c:486
 create_new_namespaces+0x3a2/0x650 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x120/0x170 kernel/nsproxy.c:231
 ksys_unshare+0x52f/0x860 kernel/fork.c:3156
 __do_sys_unshare kernel/fork.c:3224 [inline]
 __se_sys_unshare kernel/fork.c:3222 [inline]
 __x64_sys_unshare+0x38/0x40 kernel/fork.c:3222
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Freed by task 298:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4a/0x70 mm/kasan/common.c:45
 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370
 ____kasan_slab_free+0x125/0x160 mm/kasan/common.c:362
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:370
 kasan_slab_free include/linux/kasan.h:220 [inline]
 slab_free_hook mm/slub.c:1600 [inline]
 slab_free_freelist_hook+0xc5/0x190 mm/slub.c:1626
 slab_free mm/slub.c:3208 [inline]
 kmem_cache_free+0x100/0x2d0 mm/slub.c:3224
 kernfs_put+0x310/0x480 fs/kernfs/dir.c:547
 kernfs_remove_by_name_ns+0xea/0x160 fs/kernfs/dir.c:1599
 kernfs_remove_by_name include/linux/kernfs.h:623 [inline]
 remove_files fs/sysfs/group.c:28 [inline]
 sysfs_remove_group+0x105/0x2a0 fs/sysfs/group.c:289
 sysfs_remove_groups+0x56/0xb0 fs/sysfs/group.c:313
 device_remove_groups drivers/base/core.c:2371 [inline]
 device_remove_attrs+0x113/0x130 drivers/base/core.c:2568
 device_del+0x6a6/0xef0 drivers/base/core.c:3451
 netdev_unregister_kobject+0x184/0x250 net/core/net-sysfs.c:1963
 unregister_netdevice_many+0x154f/0x1a80 net/core/dev.c:10794
 ip_tunnel_delete_nets+0x34b/0x3a0 net/ipv4/ip_tunnel.c:1122
 ipip_exit_batch_net+0x22/0x30 net/ipv4/ipip.c:650
 ops_exit_list net/core/net_namespace.c:190 [inline]
 cleanup_net+0x603/0xb80 net/core/net_namespace.c:609
 process_one_work+0x6e1/0xba0 kernel/workqueue.c:2301
 worker_thread+0xa6a/0x13c0 kernel/workqueue.c:2447
 kthread+0x346/0x3d0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

The buggy address belongs to the object at ffff888110b1f000
 which belongs to the cache kernfs_node_cache of size 144
The buggy address is located 95 bytes inside of
 144-byte region [ffff888110b1f000, ffff888110b1f090)
The buggy address belongs to the page:
page:ffffea000442c7c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x110b1f
flags: 0x4000000000000200(slab)
raw: 4000000000000200 dead000000000100 dead000000000122 ffff88810018b680
raw: 0000000000000000 0000000000130013 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 422, ts 44021786241, free_ts 44007267660
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook mm/page_alloc.c:2456 [inline]
 prep_new_page+0x179/0x180 mm/page_alloc.c:2462
 get_page_from_freelist+0x223b/0x23d0 mm/page_alloc.c:4254
 __alloc_pages_nodemask+0x290/0x620 mm/page_alloc.c:5370
 alloc_slab_page mm/slub.c:-1 [inline]
 allocate_slab mm/slub.c:1813 [inline]
 new_slab+0x84/0x3f0 mm/slub.c:1874
 new_slab_objects mm/slub.c:2632 [inline]
 ___slab_alloc+0x2a6/0x450 mm/slub.c:2796
 __slab_alloc+0x63/0xa0 mm/slub.c:2836
 slab_alloc_node mm/slub.c:2918 [inline]
 slab_alloc mm/slub.c:2960 [inline]
 kmem_cache_alloc+0x1ac/0x2d0 mm/slub.c:2965
 kmem_cache_zalloc include/linux/slab.h:657 [inline]
 __kernfs_new_node+0xe3/0x6b0 fs/kernfs/dir.c:662
 kernfs_new_node+0x150/0x260 fs/kernfs/dir.c:739
 __kernfs_create_file+0x4e/0x270 fs/kernfs/file.c:987
 sysfs_add_file_mode_ns+0x29a/0x350 fs/sysfs/file.c:306
 create_files fs/sysfs/group.c:64 [inline]
 internal_create_group+0x495/0xd00 fs/sysfs/group.c:149
 internal_create_groups fs/sysfs/group.c:189 [inline]
 sysfs_create_groups+0x58/0x120 fs/sysfs/group.c:215
 device_add_groups drivers/base/core.c:2364 [inline]
 device_add_attrs+0x8c/0x430 drivers/base/core.c:2512
 device_add+0x504/0xbf0 drivers/base/core.c:3224
 netdev_register_kobject+0x1bc/0x360 net/core/net-sysfs.c:1997
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:28 [inline]
 free_pages_prepare mm/page_alloc.c:1349 [inline]
 free_pcp_prepare mm/page_alloc.c:1421 [inline]
 free_unref_page_prepare+0x2b7/0x2d0 mm/page_alloc.c:3336
 free_unref_page_list+0x129/0x9c0 mm/page_alloc.c:3443
 release_pages+0xe52/0xea0 mm/swap.c:1103
 free_pages_and_swap_cache+0x86/0xa0 mm/swap_state.c:356
 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:240 [inline]
 tlb_flush_mmu mm/mmu_gather.c:247 [inline]
 tlb_finish_mmu+0x17e/0x310 mm/mmu_gather.c:326
 exit_mmap+0x329/0x590 mm/mmap.c:3387
 __mmput+0x93/0x2f0 kernel/fork.c:1153
 mmput+0x4e/0x150 kernel/fork.c:1176
 exit_mm kernel/exit.c:539 [inline]
 do_exit+0x9ec/0x2500 kernel/exit.c:859
 do_group_exit+0x141/0x310 kernel/exit.c:986
 get_signal+0xf7d/0x12e0 kernel/signal.c:2793
 arch_do_signal_or_restart+0xe2/0x11d0 arch/x86/kernel/signal.c:805
 handle_signal_work kernel/entry/common.c:145 [inline]
 exit_to_user_mode_loop+0xa2/0xe0 kernel/entry/common.c:169
 exit_to_user_mode_prepare+0x76/0xa0 kernel/entry/common.c:199
 syscall_exit_to_user_mode+0x1d/0x40 kernel/entry/common.c:274
 do_syscall_64+0x3d/0x40 arch/x86/entry/common.c:56

Memory state around the buggy address:
 ffff888110b1ef00: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc
 ffff888110b1ef80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888110b1f000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                    ^
 ffff888110b1f080: fb fb fc fc fc fc fc fc fc fc fa fb fb fb fb fb
 ffff888110b1f100: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
==================================================================
EXT4-fs error (device loop2): ext4_inlinedir_to_tree:1457: inode #12: block 7: comm syz.2.18: path /1/file1/file0: bad entry in directory: rec_len % 4 != 0 - offset=39503, inode=3885038053, rec_len=39499, size=112 fake=0