EXT4-fs warning (device loop0): dx_probe:966: inode #2: comm syz.0.15: 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 ffff88804d884003 by task syz.0.15/5579

CPU: 0 UID: 0 PID: 5579 Comm: syz.0.15 Not tainted 6.12.0-syzkaller-07834-g06afb0f36106 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
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:377 [inline]
 print_report+0x169/0x550 mm/kasan/report.c:488
 kasan_report+0x143/0x180 mm/kasan/report.c:601
 __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: 0033:0x7fbd6697e819
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:00007ffe07c5c518 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 00007fbd66b35fa0 RCX: 00007fbd6697e819
RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 00007fbd669f175e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbd66b35fa0 R14: 00007fbd66b35fa0 R15: 0000000000000175
 </TASK>

Allocated by task 1089:
 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:257 [inline]
 __do_kmalloc_node mm/slub.c:4264 [inline]
 __kmalloc_node_track_caller_noprof+0x225/0x440 mm/slub.c:4283
 kmalloc_reserve+0x111/0x2a0 net/core/skbuff.c:609
 __alloc_skb+0x1f3/0x440 net/core/skbuff.c:678
 alloc_skb include/linux/skbuff.h:1323 [inline]
 nlmsg_new include/net/netlink.h:1018 [inline]
 inet6_rt_notify+0xba/0x240 net/ipv6/route.c:6195
 fib6_add_rt2node net/ipv6/ip6_fib.c:1259 [inline]
 fib6_add+0x1e33/0x4420 net/ipv6/ip6_fib.c:1488
 __ip6_ins_rt net/ipv6/route.c:1317 [inline]
 ip6_route_add+0x8b/0x160 net/ipv6/route.c:3857
 addrconf_add_mroute net/ipv6/addrconf.c:2550 [inline]
 addrconf_add_dev+0x35b/0x540 net/ipv6/addrconf.c:2568
 addrconf_dev_config net/ipv6/addrconf.c:3484 [inline]
 addrconf_init_auto_addrs+0x85f/0xeb0 net/ipv6/addrconf.c:3572
 addrconf_notify+0xaff/0x1020 net/ipv6/addrconf.c:3745
 notifier_call_chain+0x19f/0x3e0 kernel/notifier.c:93
 netdev_state_change+0x11f/0x1a0 net/core/dev.c:1378
 linkwatch_do_dev+0x112/0x170 net/core/link_watch.c:177
 __linkwatch_run_queue+0x44f/0x6c0 net/core/link_watch.c:234
 linkwatch_event+0x4c/0x60 net/core/link_watch.c:277
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 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

Freed by task 1089:
 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:579
 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:230 [inline]
 slab_free_hook mm/slub.c:2342 [inline]
 slab_free mm/slub.c:4579 [inline]
 kfree+0x1a0/0x440 mm/slub.c:4727
 skb_kfree_head net/core/skbuff.c:1086 [inline]
 skb_free_head net/core/skbuff.c:1098 [inline]
 skb_release_data+0x6a0/0x8a0 net/core/skbuff.c:1125
 skb_release_all net/core/skbuff.c:1190 [inline]
 __kfree_skb net/core/skbuff.c:1204 [inline]
 consume_skb+0x9f/0xf0 net/core/skbuff.c:1436
 netlink_broadcast_filtered+0x116d/0x12a0 net/netlink/af_netlink.c:1532
 nlmsg_multicast_filtered include/net/netlink.h:1128 [inline]
 nlmsg_multicast include/net/netlink.h:1147 [inline]
 nlmsg_notify+0xfb/0x1c0 net/netlink/af_netlink.c:2584
 fib6_add_rt2node net/ipv6/ip6_fib.c:1259 [inline]
 fib6_add+0x1e33/0x4420 net/ipv6/ip6_fib.c:1488
 __ip6_ins_rt net/ipv6/route.c:1317 [inline]
 ip6_route_add+0x8b/0x160 net/ipv6/route.c:3857
 addrconf_add_mroute net/ipv6/addrconf.c:2550 [inline]
 addrconf_add_dev+0x35b/0x540 net/ipv6/addrconf.c:2568
 addrconf_dev_config net/ipv6/addrconf.c:3484 [inline]
 addrconf_init_auto_addrs+0x85f/0xeb0 net/ipv6/addrconf.c:3572
 addrconf_notify+0xaff/0x1020 net/ipv6/addrconf.c:3745
 notifier_call_chain+0x19f/0x3e0 kernel/notifier.c:93
 netdev_state_change+0x11f/0x1a0 net/core/dev.c:1378
 linkwatch_do_dev+0x112/0x170 net/core/link_watch.c:177
 __linkwatch_run_queue+0x44f/0x6c0 net/core/link_watch.c:234
 linkwatch_event+0x4c/0x60 net/core/link_watch.c:277
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 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

The buggy address belongs to the object at ffff88804d884000
 which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 3 bytes inside of
 freed 1024-byte region [ffff88804d884000, ffff88804d884400)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4d884
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000040 ffff88801ac41dc0 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000080008 00000001f5000000 0000000000000000
head: 04fff00000000040 ffff88801ac41dc0 dead000000000122 0000000000000000
head: 0000000000000000 0000000000080008 00000001f5000000 0000000000000000
head: 04fff00000000002 ffffea0001362101 ffffffffffffffff 0000000000000000
head: 0000000700000004 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1089, tgid 1089 (kworker/u4:9), ts 91096608944, free_ts 91076411823
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1556
 prep_new_page mm/page_alloc.c:1564 [inline]
 get_page_from_freelist+0x3649/0x3790 mm/page_alloc.c:3474
 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4751
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265
 alloc_slab_page+0x6a/0x140 mm/slub.c:2412
 allocate_slab+0x5a/0x2f0 mm/slub.c:2578
 new_slab mm/slub.c:2631 [inline]
 ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3818
 __slab_alloc+0x58/0xa0 mm/slub.c:3908
 __slab_alloc_node mm/slub.c:3961 [inline]
 slab_alloc_node mm/slub.c:4122 [inline]
 __do_kmalloc_node mm/slub.c:4263 [inline]
 __kmalloc_node_track_caller_noprof+0x281/0x440 mm/slub.c:4283
 kmalloc_reserve+0x111/0x2a0 net/core/skbuff.c:609
 __alloc_skb+0x1f3/0x440 net/core/skbuff.c:678
 alloc_skb include/linux/skbuff.h:1323 [inline]
 nlmsg_new include/net/netlink.h:1018 [inline]
 inet6_rt_notify+0xba/0x240 net/ipv6/route.c:6195
 fib6_add_rt2node net/ipv6/ip6_fib.c:1259 [inline]
 fib6_add+0x1e33/0x4420 net/ipv6/ip6_fib.c:1488
 __ip6_ins_rt net/ipv6/route.c:1317 [inline]
 ip6_route_add+0x8b/0x160 net/ipv6/route.c:3857
 addrconf_add_mroute net/ipv6/addrconf.c:2550 [inline]
 addrconf_add_dev+0x35b/0x540 net/ipv6/addrconf.c:2568
 addrconf_dev_config net/ipv6/addrconf.c:3484 [inline]
 addrconf_init_auto_addrs+0x85f/0xeb0 net/ipv6/addrconf.c:3572
page last free pid 5579 tgid 5579 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1127 [inline]
 free_unref_page+0xdf9/0x1140 mm/page_alloc.c:2657
 stack_depot_save_flags+0x6f6/0x830 lib/stackdepot.c:666
 kasan_save_stack mm/kasan/common.c:48 [inline]
 kasan_save_track+0x51/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
 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:230 [inline]
 slab_free_hook mm/slub.c:2342 [inline]
 slab_free mm/slub.c:4579 [inline]
 kfree+0x1a0/0x440 mm/slub.c:4727
 __kthread_create_on_node+0x319/0x3c0 kernel/kthread.c:477
 kthread_create_on_node+0xde/0x130 kernel/kthread.c:513
 init_rescuer+0x2df/0x570 kernel/workqueue.c:5562
 __alloc_workqueue+0x1b11/0x1f20 kernel/workqueue.c:5731
 alloc_workqueue+0xd6/0x210 kernel/workqueue.c:5772
 __ext4_fill_super fs/ext4/super.c:5493 [inline]
 ext4_fill_super+0x5666/0x6e60 fs/ext4/super.c:5733
 get_tree_bdev_flags+0x48c/0x5c0 fs/super.c:1636
 vfs_get_tree+0x90/0x2b0 fs/super.c:1814
 do_new_mount+0x2be/0xb40 fs/namespace.c:3507
 do_mount fs/namespace.c:3847 [inline]
 __do_sys_mount fs/namespace.c:4057 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:4034

Memory state around the buggy address:
 ffff88804d883f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88804d883f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88804d884000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff88804d884080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88804d884100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================