[EXT4 FS bs=1024, gc=1, bpg=8192, ipg=32, mo=a806e02c, mo2=0002]
System zones: 1-12
EXT4-fs error (device loop3): dx_probe:823: inode #2: comm syz.3.3440: Directory hole found for htree index block 0
==================================================================
BUG: KASAN: use-after-free in hlist_add_head include/linux/list.h:930 [inline]
BUG: KASAN: use-after-free in enqueue_timer+0xae/0x480 kernel/time/timer.c:611
Write of size 8 at addr ffff888131c7e4c0 by task syz.3.3440/14897

CPU: 1 PID: 14897 Comm: syz.3.3440 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
 <TASK>
 __dump_stack+0x21/0x24 lib/dump_stack.c:88
 dump_stack_lvl+0xee/0x150 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
 __asan_report_store8_noabort+0x17/0x20 mm/kasan/report_generic.c:356
 hlist_add_head include/linux/list.h:930 [inline]
 enqueue_timer+0xae/0x480 kernel/time/timer.c:611
 __mod_timer+0x79f/0xb30 kernel/time/timer.c:-1
 mod_timer+0x1f/0x30 kernel/time/timer.c:1172
 ext4_update_super+0xa54/0xe40 fs/ext4/super.c:6070
 ext4_commit_super+0xe3/0x4b0 fs/ext4/super.c:6089
 ext4_handle_error+0x5c8/0x860 fs/ext4/super.c:678
 __ext4_error_inode+0x2ce/0x560 fs/ext4/super.c:811
 __ext4_read_dirblock+0x19e/0x8e0 fs/ext4/namei.c:-1
 dx_probe+0xb1/0x15c0 fs/ext4/namei.c:823
 ext4_dx_find_entry fs/ext4/namei.c:1793 [inline]
 __ext4_find_entry+0x514/0x1a70 fs/ext4/namei.c:1636
 ext4_lookup_entry fs/ext4/namei.c:1774 [inline]
 ext4_lookup+0x144/0x6d0 fs/ext4/namei.c:1842
 __lookup_slow+0x2c7/0x3f0 fs/namei.c:1689
 lookup_slow fs/namei.c:1706 [inline]
 lookup_one_unlocked+0x17a/0x2a0 fs/namei.c:2800
 lookup_one_positive_unlocked fs/namei.c:2829 [inline]
 lookup_positive_unlocked+0x2a/0xb0 fs/namei.c:2869
 dquot_quota_on_mount+0x5a/0xe0 fs/quota/dquot.c:2576
 ext4_quota_on_mount fs/ext4/orphan.c:316 [inline]
 ext4_orphan_cleanup+0x688/0x1210 fs/ext4/orphan.c:444
 __ext4_fill_super fs/ext4/super.c:5524 [inline]
 ext4_fill_super+0x7439/0x7970 fs/ext4/super.c:5655
 get_tree_bdev+0x444/0x680 fs/super.c:1368
 ext4_get_tree+0x1c/0x20 fs/ext4/super.c:5685
 vfs_get_tree+0x9a/0x270 fs/super.c:1575
 do_new_mount+0x25a/0xa20 fs/namespace.c:3069
 path_mount+0x675/0x1010 fs/namespace.c:3399
 do_mount fs/namespace.c:3412 [inline]
 __do_sys_mount fs/namespace.c:3620 [inline]
 __se_sys_mount+0x318/0x380 fs/namespace.c:3597
 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3597
 x64_sys_call+0x65d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7feeed59066a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007feeebff6e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007feeebff6ef0 RCX: 00007feeed59066a
RDX: 0000200000000080 RSI: 0000200000000480 RDI: 00007feeebff6eb0
RBP: 0000200000000080 R08: 00007feeebff6ef0 R09: 0000000000000010
R10: 0000000000000010 R11: 0000000000000246 R12: 0000200000000480
R13: 00007feeebff6eb0 R14: 00000000000004c2 R15: 000000000000002c
 </TASK>

Allocated by task 14750:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 kasan_save_alloc_info+0x25/0x30 mm/kasan/generic.c:505
 ____kasan_kmalloc mm/kasan/common.c:379 [inline]
 __kasan_kmalloc+0x95/0xb0 mm/kasan/common.c:388
 kasan_kmalloc include/linux/kasan.h:212 [inline]
 kmalloc_trace+0x40/0xb0 mm/slab_common.c:1033
 kmalloc include/linux/slab.h:563 [inline]
 kzalloc include/linux/slab.h:699 [inline]
 ext4_alloc_sbi fs/ext4/super.c:4263 [inline]
 ext4_fill_super+0x107/0x7970 fs/ext4/super.c:5642
 get_tree_bdev+0x444/0x680 fs/super.c:1368
 ext4_get_tree+0x1c/0x20 fs/ext4/super.c:5685
 vfs_get_tree+0x9a/0x270 fs/super.c:1575
 do_new_mount+0x25a/0xa20 fs/namespace.c:3069
 path_mount+0x675/0x1010 fs/namespace.c:3399
 do_mount fs/namespace.c:3412 [inline]
 __do_sys_mount fs/namespace.c:3620 [inline]
 __se_sys_mount+0x318/0x380 fs/namespace.c:3597
 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3597
 x64_sys_call+0x65d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Freed by task 13195:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 kasan_save_free_info+0x31/0x50 mm/kasan/generic.c:516
 ____kasan_slab_free+0x132/0x180 mm/kasan/common.c:241
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:249
 kasan_slab_free include/linux/kasan.h:178 [inline]
 slab_free_hook mm/slub.c:1750 [inline]
 slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1776
 slab_free mm/slub.c:3712 [inline]
 __kmem_cache_free+0xb7/0x1b0 mm/slub.c:3728
 kfree+0x6f/0xf0 mm/slab_common.c:990
 ext4_put_super+0x9b6/0xac0 fs/ext4/super.c:1313
 generic_shutdown_super+0x15f/0x370 fs/super.c:503
 kill_block_super+0x7f/0xf0 fs/super.c:1472
 deactivate_locked_super+0xb5/0x120 fs/super.c:334
 deactivate_super+0xaf/0xe0 fs/super.c:365
 cleanup_mnt+0x45f/0x4e0 fs/namespace.c:1182
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1189
 task_work_run+0x1db/0x240 kernel/task_work.c:203
 exit_task_work include/linux/task_work.h:39 [inline]
 do_exit+0xa25/0x2650 kernel/exit.c:886
 do_group_exit+0x210/0x2d0 kernel/exit.c:1028
 __do_sys_exit_group kernel/exit.c:1039 [inline]
 __se_sys_exit_group kernel/exit.c:1037 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1037
 x64_sys_call+0x7b4/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Last potentially related work creation:
 kasan_save_stack+0x3a/0x60 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xb6/0xc0 mm/kasan/generic.c:486
 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:496
 kvfree_call_rcu+0x95/0x7a0 kernel/rcu/tree.c:3445
 drop_sysctl_table+0x2ef/0x410 fs/proc/proc_sysctl.c:1731
 unregister_sysctl_table+0x75/0x120 fs/proc/proc_sysctl.c:1769
 unregister_net_sysctl_table+0x15/0x20 net/sysctl_net.c:175
 ipv4_sysctl_exit_net+0x82/0x90 net/ipv4/sysctl_net_ipv4.c:1445
 ops_exit_list net/core/net_namespace.c:172 [inline]
 cleanup_net+0x5ad/0xb00 net/core/net_namespace.c:604
 process_one_work+0x71f/0xc40 kernel/workqueue.c:2302
 worker_thread+0xa29/0x11f0 kernel/workqueue.c:2449
 kthread+0x281/0x320 kernel/kthread.c:386
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

The buggy address belongs to the object at ffff888131c7e000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 1216 bytes inside of
 4096-byte region [ffff888131c7e000, ffff888131c7f000)

The buggy address belongs to the physical page:
page:ffffea0004c71e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x131c78
head:ffffea0004c71e00 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head|zone=1)
raw: 4000000000010200 dead000000000100 dead000000000122 ffff888100043380
raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 283, tgid 283 (syz-executor), ts 26188422588, free_ts 0
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2643
 prep_new_page+0x1c/0x110 mm/page_alloc.c:2650
 get_page_from_freelist+0x2c7b/0x2cf0 mm/page_alloc.c:4554
 __alloc_pages+0x1c3/0x450 mm/page_alloc.c:5868
 alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1
 allocate_slab mm/slub.c:1967 [inline]
 new_slab+0x98/0x3d0 mm/slub.c:2020
 ___slab_alloc+0x6bd/0xb20 mm/slub.c:3177
 __slab_alloc+0x5e/0xa0 mm/slub.c:3263
 slab_alloc_node mm/slub.c:3348 [inline]
 __kmem_cache_alloc_node+0x203/0x2c0 mm/slub.c:3423
 kmalloc_trace+0x29/0xb0 mm/slab_common.c:1028
 kmalloc include/linux/slab.h:563 [inline]
 kzalloc include/linux/slab.h:699 [inline]
 kobject_uevent_env+0x287/0x730 lib/kobject_uevent.c:539
 kobject_uevent+0x1d/0x30 lib/kobject_uevent.c:657
 rx_queue_add_kobject net/core/net-sysfs.c:1068 [inline]
 net_rx_queue_update_kobjects+0x249/0x4d0 net/core/net-sysfs.c:1108
 register_queue_kobjects net/core/net-sysfs.c:1768 [inline]
 netdev_register_kobject+0x229/0x320 net/core/net-sysfs.c:2013
 register_netdevice+0xe3d/0x14a0 net/core/dev.c:10168
 veth_newlink+0x7a0/0xbe0 drivers/net/veth.c:1776
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888131c7e380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888131c7e400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888131c7e480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff888131c7e500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888131c7e580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
EXT4-fs (loop3): Remounting filesystem read-only
EXT4-fs (loop3): Cannot turn on journaled quota: type 0: error -117
EXT4-fs error (device loop3): dx_probe:823: inode #2: comm syz.3.3440: Directory hole found for htree index block 0
EXT4-fs (loop3): Remounting filesystem read-only
EXT4-fs (loop3): Cannot turn on journaled quota: type 1: error -117
EXT4-fs (loop3): mounted filesystem without journal. Quota mode: writeback.
EXT4-fs (loop3): re-mounted. Quota mode: writeback.