EXT4-fs warning (device loop3): dx_probe:892: inode #2: comm syz.3.389: dx entry: limit 0 != root limit 124
EXT4-fs warning (device loop3): dx_probe:965: inode #2: comm syz.3.389: Corrupt directory, running e2fsck is recommended
==================================================================
BUG: KASAN: use-after-free in __ext4_check_dir_entry+0x6f3/0x870 fs/ext4/dir.c:85
Read of size 2 at addr ffff88805b6ae003 by task syz.3.389/4822

CPU: 1 PID: 4822 Comm: syz.3.389 Not tainted 6.1.97-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:284 [inline]
 print_report+0x15f/0x4f0 mm/kasan/report.c:395
 kasan_report+0x136/0x160 mm/kasan/report.c:495
 __ext4_check_dir_entry+0x6f3/0x870 fs/ext4/dir.c:85
 ext4_readdir+0x139e/0x3950 fs/ext4/dir.c:258
 iterate_dir+0x224/0x560
 __do_sys_getdents64 fs/readdir.c:369 [inline]
 __se_sys_getdents64+0x209/0x4f0 fs/readdir.c:354
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fd28c975bd9
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:00007fd28d69e048 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 00007fd28cb03f60 RCX: 00007fd28c975bd9
RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000000008
RBP: 00007fd28c9e4e60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fd28cb03f60 R15: 00007fff926412e8
 </TASK>

Allocated by task 4779:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 __kasan_slab_alloc+0x65/0x70 mm/kasan/common.c:328
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook+0x52/0x3a0 mm/slab.h:737
 slab_alloc_node mm/slub.c:3398 [inline]
 kmem_cache_alloc_node+0x136/0x310 mm/slub.c:3443
 __alloc_skb+0xde/0x670 net/core/skbuff.c:505
 alloc_skb include/linux/skbuff.h:1271 [inline]
 alloc_skb_with_frags+0xa4/0x740 net/core/skbuff.c:6168
 sock_alloc_send_pskb+0x915/0xa50 net/core/sock.c:2747
 unix_dgram_sendmsg+0x5b1/0x2050 net/unix/af_unix.c:1941
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 ____sys_sendmsg+0x5a5/0x8f0 net/socket.c:2514
 ___sys_sendmsg net/socket.c:2568 [inline]
 __sys_sendmmsg+0x3ab/0x730 net/socket.c:2654
 __do_sys_sendmmsg net/socket.c:2683 [inline]
 __se_sys_sendmmsg net/socket.c:2680 [inline]
 __x64_sys_sendmmsg+0x9c/0xb0 net/socket.c:2680
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Freed by task 4779:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516
 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236
 kasan_slab_free include/linux/kasan.h:177 [inline]
 slab_free_hook mm/slub.c:1724 [inline]
 slab_free_freelist_hook mm/slub.c:1750 [inline]
 slab_free mm/slub.c:3661 [inline]
 kmem_cache_free+0x292/0x510 mm/slub.c:3683
 kfree_skb include/linux/skbuff.h:1220 [inline]
 unix_dgram_sendmsg+0xa24/0x2050 net/unix/af_unix.c:2091
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 ____sys_sendmsg+0x5a5/0x8f0 net/socket.c:2514
 ___sys_sendmsg net/socket.c:2568 [inline]
 __sys_sendmmsg+0x3ab/0x730 net/socket.c:2654
 __do_sys_sendmmsg net/socket.c:2683 [inline]
 __se_sys_sendmmsg net/socket.c:2680 [inline]
 __x64_sys_sendmmsg+0x9c/0xb0 net/socket.c:2680
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

The buggy address belongs to the object at ffff88805b6ae000
 which belongs to the cache skbuff_head_cache of size 240
The buggy address is located 3 bytes inside of
 240-byte region [ffff88805b6ae000, ffff88805b6ae0f0)

The buggy address belongs to the physical page:
page:ffffea00016dab80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5b6ae
memcg:ffff88807bb6b981
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 0000000000000000 dead000000000122 ffff8880127d3500
raw: 0000000000000000 00000000000c000c 00000001ffffffff ffff88807bb6b981
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 4779, tgid 4773 (syz.1.373), ts 118805661189, free_ts 118374635305
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x18d/0x1b0 mm/page_alloc.c:2517
 prep_new_page mm/page_alloc.c:2524 [inline]
 get_page_from_freelist+0x322e/0x33b0 mm/page_alloc.c:4283
 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5551
 alloc_slab_page+0x6a/0x150 mm/slub.c:1794
 allocate_slab mm/slub.c:1939 [inline]
 new_slab+0x84/0x2d0 mm/slub.c:1992
 ___slab_alloc+0xc20/0x1270 mm/slub.c:3180
 __slab_alloc mm/slub.c:3279 [inline]
 slab_alloc_node mm/slub.c:3364 [inline]
 kmem_cache_alloc_node+0x1cf/0x310 mm/slub.c:3443
 __alloc_skb+0xde/0x670 net/core/skbuff.c:505
 alloc_skb include/linux/skbuff.h:1271 [inline]
 alloc_skb_with_frags+0xa4/0x740 net/core/skbuff.c:6168
 sock_alloc_send_pskb+0x915/0xa50 net/core/sock.c:2747
 unix_dgram_sendmsg+0x5b1/0x2050 net/unix/af_unix.c:1941
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg net/socket.c:730 [inline]
 ____sys_sendmsg+0x5a5/0x8f0 net/socket.c:2514
 ___sys_sendmsg net/socket.c:2568 [inline]
 __sys_sendmmsg+0x3ab/0x730 net/socket.c:2654
 __do_sys_sendmmsg net/socket.c:2683 [inline]
 __se_sys_sendmmsg net/socket.c:2680 [inline]
 __x64_sys_sendmmsg+0x9c/0xb0 net/socket.c:2680
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1444 [inline]
 free_pcp_prepare mm/page_alloc.c:1494 [inline]
 free_unref_page_prepare+0xf63/0x1120 mm/page_alloc.c:3362
 free_unref_page_list+0x663/0x900 mm/page_alloc.c:3503
 release_pages+0x2836/0x2b40 mm/swap.c:1055
 tlb_batch_pages_flush mm/mmu_gather.c:59 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:254 [inline]
 tlb_flush_mmu+0xfc/0x210 mm/mmu_gather.c:261
 tlb_finish_mmu+0xce/0x1f0 mm/mmu_gather.c:361
 exit_mmap+0x3c3/0x9f0 mm/mmap.c:3239
 __mmput+0x115/0x3c0 kernel/fork.c:1199
 exit_mm+0x226/0x300 kernel/exit.c:563
 do_exit+0x9f6/0x26a0 kernel/exit.c:856
 do_group_exit+0x202/0x2b0 kernel/exit.c:1019
 __do_sys_exit_group kernel/exit.c:1030 [inline]
 __se_sys_exit_group kernel/exit.c:1028 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1028
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Memory state around the buggy address:
 ffff88805b6adf00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88805b6adf80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88805b6ae000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff88805b6ae080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
 ffff88805b6ae100: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
==================================================================