==================================================================
BUG: KASAN: slab-use-after-free in list_empty include/linux/list.h:381 [inline]
BUG: KASAN: slab-use-after-free in waitqueue_active include/linux/wait.h:127 [inline]
BUG: KASAN: slab-use-after-free in wq_has_sleeper include/linux/wait.h:161 [inline]
BUG: KASAN: slab-use-after-free in skwq_has_sleeper include/net/sock.h:2407 [inline]
BUG: KASAN: slab-use-after-free in sock_def_readable+0x1cb/0x550 net/core/sock.c:3613
Read of size 8 at addr ffff8880771bf8c0 by task modprobe/11940

CPU: 0 UID: 0 PID: 11940 Comm: modprobe Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
 <IRQ>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xba/0x230 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 list_empty include/linux/list.h:381 [inline]
 waitqueue_active include/linux/wait.h:127 [inline]
 wq_has_sleeper include/linux/wait.h:161 [inline]
 skwq_has_sleeper include/net/sock.h:2407 [inline]
 sock_def_readable+0x1cb/0x550 net/core/sock.c:3613
 send_to_lecd+0x3e7/0x830 net/atm/lec.c:559
 lec_arp_resolve net/atm/lec.c:1813 [inline]
 lec_start_xmit+0xe52/0x2890 net/atm/lec.c:294
 __netdev_start_xmit include/linux/netdevice.h:5343 [inline]
 netdev_start_xmit include/linux/netdevice.h:5352 [inline]
 xmit_one net/core/dev.c:3888 [inline]
 dev_hard_start_xmit+0x2cd/0x830 net/core/dev.c:3904
 sch_direct_xmit+0x251/0x4c0 net/sched/sch_generic.c:372
 qdisc_restart net/sched/sch_generic.c:437 [inline]
 __qdisc_run+0xa83/0x1560 net/sched/sch_generic.c:445
 qdisc_run include/net/pkt_sched.h:120 [inline]
 __dev_xmit_skb net/core/dev.c:4219 [inline]
 __dev_queue_xmit+0x1021/0x3950 net/core/dev.c:4831
 lapb_data_transmit+0x90/0xb0 net/lapb/lapb_iface.c:447
 lapb_transmit_buffer+0x163/0x200 net/lapb/lapb_out.c:149
 lapb_t1timer_expiry+0x699/0xab0 net/lapb/lapb_timer.c:-1
 call_timer_fn+0x192/0x5e0 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2374 [inline]
 __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2386
 run_timer_base kernel/time/timer.c:2395 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405
 handle_softirqs+0x22a/0x840 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:page_table_check_clear+0x299/0x5f0 mm/page_table_check.c:85
Code: be 04 00 00 00 e8 77 ca f3 ff 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 0f 85 41 01 00 00 45 8b 37 <31> ff 44 89 f6 e8 ed fe 87 ff 45 85 f6 0f 85 4a 02 00 00 49 8d 7f
RSP: 0018:ffffc9000677f590 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000001 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88801b1f9188
RBP: ffff88801b1f9140 R08: ffff88801b1f918b R09: 1ffff1100363f231
R10: dffffc0000000000 R11: ffffed100363f232 R12: 000000000000e504
R13: 0000000000000001 R14: 0000000000000000 R15: ffff88801b1f9188
 ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline]
 get_and_clear_full_ptes include/linux/pgtable.h:846 [inline]
 zap_present_folio_ptes mm/memory.c:1643 [inline]
 zap_present_ptes mm/memory.c:1725 [inline]
 do_zap_pte_range mm/memory.c:1827 [inline]
 zap_pte_range mm/memory.c:1929 [inline]
 zap_pmd_range mm/memory.c:2021 [inline]
 zap_pud_range mm/memory.c:2049 [inline]
 zap_p4d_range mm/memory.c:2070 [inline]
 unmap_page_range+0x33b3/0x48f0 mm/memory.c:2091
 unmap_single_vma mm/memory.c:2133 [inline]
 unmap_vmas+0x48f/0x6a0 mm/memory.c:2171
 exit_mmap+0x280/0x9e0 mm/mmap.c:1302
 __mmput+0x118/0x430 kernel/fork.c:1177
 exit_mm+0x18e/0x250 kernel/exit.c:581
 do_exit+0x6a2/0x23c0 kernel/exit.c:965
 do_group_exit+0x21b/0x2d0 kernel/exit.c:1119
 __do_sys_exit_group kernel/exit.c:1130 [inline]
 __se_sys_exit_group kernel/exit.c:1128 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1128
 x64_sys_call+0x221a/0x2240 arch/x86/include/generated/asm/syscalls_64.h:232
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8ec40946c5
Code: Unable to access opcode bytes at 0x7f8ec409469b.
RSP: 002b:00007fff15d4a518 EFLAGS: 00000206 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007f8ec4195fe8 RCX: 00007f8ec40946c5
RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000001
RBP: 0000000000000001 R08: 00007fff15d4a4a8 R09: 0000000000000000
R10: 00007fff15d4a340 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f8ec4194680 R15: 00007f8ec4196000
 </TASK>

Allocated by task 11899:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 unpoison_slab_object mm/kasan/common.c:340 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4538 [inline]
 slab_alloc_node mm/slub.c:4866 [inline]
 kmem_cache_alloc_lru_noprof+0x2b8/0x640 mm/slub.c:4885
 sock_alloc_inode+0x2c/0x190 net/socket.c:328
 alloc_inode+0x6a/0x1b0 fs/inode.c:345
 new_inode_pseudo include/linux/fs.h:3014 [inline]
 sock_alloc net/socket.c:697 [inline]
 __sock_create+0x12d/0x9d0 net/socket.c:1628
 sock_create net/socket.c:1722 [inline]
 __sys_socket_create net/socket.c:1759 [inline]
 __sys_socket+0xd6/0x1b0 net/socket.c:1806
 __do_sys_socket net/socket.c:1820 [inline]
 __se_sys_socket net/socket.c:1818 [inline]
 __x64_sys_socket+0x7a/0x90 net/socket.c:1818
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 11932:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2685 [inline]
 slab_free mm/slub.c:6165 [inline]
 kmem_cache_free+0x180/0x630 mm/slub.c:6295
 rcu_do_batch kernel/rcu/tree.c:2617 [inline]
 rcu_core+0x7cd/0x1070 kernel/rcu/tree.c:2869
 handle_softirqs+0x22a/0x840 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697

Last potentially related work creation:
 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57
 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
 __call_rcu_common kernel/rcu/tree.c:3131 [inline]
 call_rcu+0xee/0x890 kernel/rcu/tree.c:3251
 destroy_inode fs/inode.c:399 [inline]
 evict+0x95b/0xb10 fs/inode.c:865
 __dentry_kill+0x1a2/0x5e0 fs/dcache.c:670
 finish_dput+0xc9/0x480 fs/dcache.c:879
 __fput+0x691/0xa60 fs/file_table.c:518
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 get_signal+0x11eb/0x1330 kernel/signal.c:2811
 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
 exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:328 [inline]
 do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff8880771bf800
 which belongs to the cache sock_inode_cache of size 1408
The buggy address is located 192 bytes inside of
 freed 1408-byte region [ffff8880771bf800, ffff8880771bfd80)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x771b8
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff8880255c0301
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801def6000 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800150015 00000000f5000000 ffff8880255c0301
head: 00fff00000000040 ffff88801def6000 dead000000000100 dead000000000122
head: 0000000000000000 0000000800150015 00000000f5000000 ffff8880255c0301
head: 00fff00000000003 ffffea0001dc6e01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Reclaimable, gfp_mask 0xd20d0(__GFP_RECLAIMABLE|__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5697, tgid 5697 (sftp-server), ts 67360463090, free_ts 26966027432
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889
 prep_new_page mm/page_alloc.c:1897 [inline]
 get_page_from_freelist+0x24dc/0x2580 mm/page_alloc.c:3962
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250
 alloc_slab_page mm/slub.c:3292 [inline]
 allocate_slab+0x77/0x660 mm/slub.c:3481
 new_slab mm/slub.c:3539 [inline]
 refill_objects+0x331/0x3c0 mm/slub.c:7175
 refill_sheaf mm/slub.c:2812 [inline]
 __pcs_replace_empty_main+0x2e6/0x730 mm/slub.c:4615
 alloc_from_pcs mm/slub.c:4717 [inline]
 slab_alloc_node mm/slub.c:4851 [inline]
 kmem_cache_alloc_lru_noprof+0x37c/0x640 mm/slub.c:4885
 sock_alloc_inode+0x2c/0x190 net/socket.c:328
 alloc_inode+0x6a/0x1b0 fs/inode.c:345
 new_inode_pseudo include/linux/fs.h:3014 [inline]
 sock_alloc net/socket.c:697 [inline]
 __sock_create+0x12d/0x9d0 net/socket.c:1628
 sock_create net/socket.c:1722 [inline]
 __sys_socket_create net/socket.c:1759 [inline]
 __sys_socket+0xd6/0x1b0 net/socket.c:1806
 __do_sys_socket net/socket.c:1820 [inline]
 __se_sys_socket net/socket.c:1818 [inline]
 __x64_sys_socket+0x7a/0x90 net/socket.c:1818
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 1 tgid 1 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0xc2b/0xdb0 mm/page_alloc.c:2978
 __free_pages mm/page_alloc.c:5369 [inline]
 free_contig_range+0xbb/0x170 mm/page_alloc.c:7374
 destroy_args+0x4e5/0x570 mm/debug_vm_pgtable.c:993
 debug_vm_pgtable+0x3f8/0x410 mm/debug_vm_pgtable.c:1368
 do_one_initcall+0x250/0x870 init/main.c:1392
 do_initcall_level+0x104/0x190 init/main.c:1454
 do_initcalls+0x59/0xa0 init/main.c:1470
 kernel_init_freeable+0x2a6/0x3e0 init/main.c:1703
 kernel_init+0x1d/0x1d0 init/main.c:1593
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffff8880771bf780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880771bf800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880771bf880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff8880771bf900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880771bf980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	be 04 00 00 00       	mov    $0x4,%esi
   5:	e8 77 ca f3 ff       	call   0xfff3ca81
   a:	4c 89 f8             	mov    %r15,%rax
   d:	48 c1 e8 03          	shr    $0x3,%rax
  11:	48 b9 00 00 00 00 00 	movabs $0xdffffc0000000000,%rcx
  18:	fc ff df
  1b:	0f b6 04 08          	movzbl (%rax,%rcx,1),%eax
  1f:	84 c0                	test   %al,%al
  21:	0f 85 41 01 00 00    	jne    0x168
  27:	45 8b 37             	mov    (%r15),%r14d
* 2a:	31 ff                	xor    %edi,%edi <-- trapping instruction
  2c:	44 89 f6             	mov    %r14d,%esi
  2f:	e8 ed fe 87 ff       	call   0xff87ff21
  34:	45 85 f6             	test   %r14d,%r14d
  37:	0f 85 4a 02 00 00    	jne    0x287
  3d:	49                   	rex.WB
  3e:	8d                   	.byte 0x8d
  3f:	7f                   	.byte 0x7f