EXT4-fs warning (device loop2): dx_probe:833: inode #2: comm syz.2.22: Unrecognised inode hash code 4
EXT4-fs warning (device loop2): dx_probe:966: inode #2: comm syz.2.22: Corrupt directory, running e2fsck is recommended
==================================================================
BUG: KASAN: slab-use-after-free in __ext4_check_dir_entry+0x6fd/0x880 fs/ext4/dir.c:85
Read of size 2 at addr ffff888034b9e003 by task syz.2.22/6820

CPU: 1 UID: 0 PID: 6820 Comm: syz.2.22 Not tainted 6.13.0-rc7-syzkaller-00191-gfda5e3f28400 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:489
 kasan_report+0x143/0x180 mm/kasan/report.c:602
 __ext4_check_dir_entry+0x6fd/0x880 fs/ext4/dir.c:85
 ext4_readdir+0x1436/0x3a60 fs/ext4/dir.c:259
 iterate_dir+0x571/0x800 fs/readdir.c:108
 __do_sys_getdents64 fs/readdir.c:403 [inline]
 __se_sys_getdents64+0x1e2/0x4b0 fs/readdir.c:389
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc720785d29
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc721653038 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 00007fc720975fa0 RCX: 00007fc720785d29
RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000000006
RBP: 00007fc720801b08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fc720975fa0 R15: 00007ffd292dfe68
 </TASK>

Allocated by task 6825:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __kmalloc_cache_noprof+0x243/0x390 mm/slub.c:4329
 kmalloc_noprof include/linux/slab.h:901 [inline]
 slab_free_hook mm/slub.c:2305 [inline]
 slab_free mm/slub.c:4613 [inline]
 kmem_cache_free+0x16c/0x410 mm/slub.c:4715
 __exit_signal kernel/exit.c:211 [inline]
 release_task+0x111e/0x1830 kernel/exit.c:257
 wait_task_zombie kernel/exit.c:1249 [inline]
 wait_consider_task+0x1a14/0x2e60 kernel/exit.c:1476
 do_wait_thread kernel/exit.c:1539 [inline]
 __do_wait+0x1b0/0x850 kernel/exit.c:1657
 do_wait+0x2e3/0x550 kernel/exit.c:1691
 kernel_wait4+0x2a7/0x3e0 kernel/exit.c:1850
 __do_sys_wait4 kernel/exit.c:1878 [inline]
 __se_sys_wait4 kernel/exit.c:1874 [inline]
 __x64_sys_wait4+0x134/0x1e0 kernel/exit.c:1874
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 9:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:582
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2353 [inline]
 slab_free mm/slub.c:4613 [inline]
 kfree+0x196/0x430 mm/slub.c:4761
 slab_free_after_rcu_debug+0x62/0x280 mm/slub.c:4650
 rcu_do_batch kernel/rcu/tree.c:2567 [inline]
 rcu_core+0xaaa/0x17a0 kernel/rcu/tree.c:2823
 handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561
 do_softirq+0x11b/0x1e0 kernel/softirq.c:462
 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:389
 ipv6_get_lladdr+0x295/0x3d0 net/ipv6/addrconf.c:1936
 mld_newpack+0x337/0xaf0 net/ipv6/mcast.c:1755
 add_grhead net/ipv6/mcast.c:1850 [inline]
 add_grec+0x1492/0x19a0 net/ipv6/mcast.c:1988
 mld_send_cr net/ipv6/mcast.c:2114 [inline]
 mld_ifc_work+0x691/0xd90 net/ipv6/mcast.c:2651
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317
 worker_thread+0x870/0xd30 kernel/workqueue.c:3398
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Last potentially related work creation:
 kasan_save_stack+0x3f/0x60 mm/kasan/common.c:47
 __kasan_record_aux_stack+0xac/0xc0 mm/kasan/generic.c:544
 __call_rcu_common kernel/rcu/tree.c:3086 [inline]
 call_rcu+0x167/0xa70 kernel/rcu/tree.c:3190
 slab_free_hook mm/slub.c:2317 [inline]
 slab_free mm/slub.c:4613 [inline]
 kmem_cache_free+0x30e/0x410 mm/slub.c:4715
 __exit_signal kernel/exit.c:211 [inline]
 release_task+0x111e/0x1830 kernel/exit.c:257
 wait_task_zombie kernel/exit.c:1249 [inline]
 wait_consider_task+0x1a14/0x2e60 kernel/exit.c:1476
 do_wait_thread kernel/exit.c:1539 [inline]
 __do_wait+0x1b0/0x850 kernel/exit.c:1657
 do_wait+0x2e3/0x550 kernel/exit.c:1691
 kernel_wait4+0x2a7/0x3e0 kernel/exit.c:1850
 __do_sys_wait4 kernel/exit.c:1878 [inline]
 __se_sys_wait4 kernel/exit.c:1874 [inline]
 __x64_sys_wait4+0x134/0x1e0 kernel/exit.c:1874
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888034b9e000
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 3 bytes inside of
 freed 32-byte region [ffff888034b9e000, ffff888034b9e020)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x34b9e
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88801ac41780 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000400040 00000001f5000000 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 0x52800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP), pid 6825, tgid 6825 (dhcpcd-run-hook), ts 116902107998, free_ts 116721959221
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1558
 prep_new_page mm/page_alloc.c:1566 [inline]
 get_page_from_freelist+0x3651/0x37a0 mm/page_alloc.c:3476
 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4753
 alloc_pages_mpol_noprof+0x3e1/0x780 mm/mempolicy.c:2269
 alloc_slab_page+0x6a/0x110 mm/slub.c:2423
 allocate_slab+0x5a/0x2b0 mm/slub.c:2589
 new_slab mm/slub.c:2642 [inline]
 ___slab_alloc+0xc27/0x14a0 mm/slub.c:3830
 __slab_alloc+0x58/0xa0 mm/slub.c:3920
 __slab_alloc_node mm/slub.c:3995 [inline]
 slab_alloc_node mm/slub.c:4156 [inline]
 __kmalloc_cache_noprof+0x27b/0x390 mm/slub.c:4324
 kmalloc_noprof include/linux/slab.h:901 [inline]
 slab_free_hook mm/slub.c:2305 [inline]
 slab_free mm/slub.c:4613 [inline]
 kmem_cache_free+0x16c/0x410 mm/slub.c:4715
 __exit_signal kernel/exit.c:211 [inline]
 release_task+0x111e/0x1830 kernel/exit.c:257
 wait_task_zombie kernel/exit.c:1249 [inline]
 wait_consider_task+0x1a14/0x2e60 kernel/exit.c:1476
 do_wait_thread kernel/exit.c:1539 [inline]
 __do_wait+0x1b0/0x850 kernel/exit.c:1657
 do_wait+0x2e3/0x550 kernel/exit.c:1691
 kernel_wait4+0x2a7/0x3e0 kernel/exit.c:1850
 __do_sys_wait4 kernel/exit.c:1878 [inline]
 __se_sys_wait4 kernel/exit.c:1874 [inline]
 __x64_sys_wait4+0x134/0x1e0 kernel/exit.c:1874
page last free pid 6574 tgid 6574 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_unref_page+0xd2c/0x1000 mm/page_alloc.c:2659
 discard_slab mm/slub.c:2688 [inline]
 __put_partials+0x160/0x1c0 mm/slub.c:3157
 put_cpu_partial+0x17c/0x250 mm/slub.c:3232
 __slab_free+0x290/0x380 mm/slub.c:4483
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4119 [inline]
 slab_alloc_node mm/slub.c:4168 [inline]
 kmem_cache_alloc_noprof+0x1d9/0x380 mm/slub.c:4175
 getname_flags+0xb7/0x540 fs/namei.c:139
 user_path_at+0x24/0x60 fs/namei.c:3069
 inotify_find_inode fs/notify/inotify/inotify_user.c:377 [inline]
 __do_sys_inotify_add_watch fs/notify/inotify/inotify_user.c:771 [inline]
 __se_sys_inotify_add_watch+0x19c/0xf20 fs/notify/inotify/inotify_user.c:729
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff888034b9df00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888034b9df80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888034b9e000: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
                   ^
 ffff888034b9e080: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
 ffff888034b9e100: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc
==================================================================