==================================================================
BUG: KASAN: slab-out-of-bounds in __bpf_get_stackid+0x6c9/0x920 kernel/bpf/stackmap.c:274
Write of size 64 at addr ffff888023c33090 by task syz.0.6339/26038

CPU: 0 PID: 26038 Comm: syz.0.6339 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <IRQ>
 dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:316 [inline]
 print_report+0xa8/0x210 mm/kasan/report.c:420
 kasan_report+0x10b/0x140 mm/kasan/report.c:524
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x235/0x290 mm/kasan/generic.c:189
 memcpy+0x3c/0x60 mm/kasan/shadow.c:66
 __bpf_get_stackid+0x6c9/0x920 kernel/bpf/stackmap.c:274
 ____bpf_get_stackid_pe kernel/bpf/stackmap.c:365 [inline]
 bpf_get_stackid_pe+0x33f/0x400 kernel/bpf/stackmap.c:334
 bpf_prog_709c33675fcd9051+0x21/0x36
 bpf_dispatcher_nop_func include/linux/bpf.h:1012 [inline]
 __bpf_prog_run include/linux/filter.h:607 [inline]
 bpf_prog_run include/linux/filter.h:614 [inline]
 bpf_overflow_handler+0x522/0x7c0 kernel/events/core.c:10286
 __perf_event_overflow+0x448/0x610 kernel/events/core.c:9496
 perf_swevent_hrtimer+0x3ef/0x590 kernel/events/core.c:10927
 __run_hrtimer kernel/time/hrtimer.c:1747 [inline]
 __hrtimer_run_queues+0x50b/0xd50 kernel/time/hrtimer.c:1811
 hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1873
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline]
 __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:interrupt_context_level include/linux/preempt.h:95 [inline]
RIP: 0010:get_recursion_context kernel/events/internal.h:214 [inline]
RIP: 0010:perf_swevent_get_recursion_context kernel/events/core.c:9725 [inline]
RIP: 0010:perf_pending_task+0x7d/0x470 kernel/events/core.c:6700
Code: 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 f7 e8 ba 6d 2b 00 4d 8b 3e 65 8b 05 48 7f 5a 7e 41 89 c6 4c 89 f6 48 81 e6 00 00 f0 00 <40> 0f 95 c5 31 ff e8 78 86 da ff 4c 89 f6 48 81 e6 00 00 ff 00 41
RSP: 0018:ffffc90003577dc0 EFLAGS: 00000246
RAX: 0000000080000001 RBX: ffff88805ed46a58 RCX: 0000000000080000
RDX: ffffc90019ea9000 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 0000000000000000 R08: ffff8880330ee343 R09: 1ffff1100661dc68
R10: dffffc0000000000 R11: ffffed100661dc69 R12: dffffc0000000000
R13: dffffc0000000000 R14: 0000000080000001 R15: ffff8880b8e00000
 task_work_run+0x1d0/0x260 kernel/task_work.c:203
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f413d59c799
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f413e5320e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000001 RBX: 00007f413d815fa8 RCX: 00007f413d59c799
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f413d815fac
RBP: 00007f413d815fa0 R08: 000d414ba3a4c9b2 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f413d816038 R14: 00007ffc08f93fa0 R15: 00007ffc08f94088
 </TASK>

Allocated by task 26038:
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
 ____kasan_kmalloc mm/kasan/common.c:375 [inline]
 __kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:384
 kasan_kmalloc include/linux/kasan.h:211 [inline]
 __do_kmalloc_node mm/slab_common.c:936 [inline]
 __kmalloc_node+0xb0/0x240 mm/slab_common.c:943
 kmalloc_node include/linux/slab.h:589 [inline]
 __bpf_map_area_alloc kernel/bpf/syscall.c:328 [inline]
 bpf_map_area_alloc+0x47/0xe0 kernel/bpf/syscall.c:341
 prealloc_elems_and_freelist+0x86/0x1c0 kernel/bpf/stackmap.c:51
 stack_map_alloc+0x390/0x520 kernel/bpf/stackmap.c:117
 find_and_alloc_map kernel/bpf/syscall.c:133 [inline]
 map_create+0x534/0x1000 kernel/bpf/syscall.c:1149
 __sys_bpf+0x38b/0x780 kernel/bpf/syscall.c:5012
 __do_sys_bpf kernel/bpf/syscall.c:5134 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5132 [inline]
 __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5132
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Last potentially related work creation:
 kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46
 __kasan_record_aux_stack+0xb2/0xc0 mm/kasan/generic.c:486
 call_rcu+0x14f/0x990 kernel/rcu/tree.c:2849
 nf_unregister_net_hook net/netfilter/core.c:-1 [inline]
 nf_unregister_net_hooks+0xc7/0x130 net/netfilter/core.c:601
 brnf_exit_net+0x5d/0x120 net/bridge/br_netfilter_hooks.c:1307
 ops_exit_list net/core/net_namespace.c:172 [inline]
 cleanup_net+0x706/0xba0 net/core/net_namespace.c:640
 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292
 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

Second to last potentially related work creation:
 kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46
 __kasan_record_aux_stack+0xb2/0xc0 mm/kasan/generic.c:486
 call_rcu+0x14f/0x990 kernel/rcu/tree.c:2849
 nf_hook_entries_free net/netfilter/core.c:88 [inline]
 __nf_register_net_hook+0x788/0x910 net/netfilter/core.c:445
 nf_register_net_hook+0xae/0x190 net/netfilter/core.c:566
 nf_register_net_hooks+0x40/0x1a0 net/netfilter/core.c:582
 nf_ct_netns_do_get+0x3bc/0x5b0 net/netfilter/nf_conntrack_proto.c:482
 nf_ct_netns_inet_get+0x1f/0x150 net/netfilter/nf_conntrack_proto.c:591
 nf_conncount_init+0x123/0x380 net/netfilter/nf_conncount.c:640
 ovs_ct_limit_init net/openvswitch/conntrack.c:1902 [inline]
 ovs_ct_init+0x312/0x480 net/openvswitch/conntrack.c:2311
 ovs_init_net+0x1e2/0x240 net/openvswitch/datapath.c:2613
 ops_init+0x355/0x5f0 net/core/net_namespace.c:138
 setup_net+0x4f2/0xbd0 net/core/net_namespace.c:336
 copy_net_ns+0x348/0x5b0 net/core/net_namespace.c:508
 create_new_namespaces+0x3d3/0x6f0 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0x116/0x160 kernel/nsproxy.c:226
 ksys_unshare+0x4ca/0x8b0 kernel/fork.c:3282
 __do_sys_unshare kernel/fork.c:3353 [inline]
 __se_sys_unshare kernel/fork.c:3351 [inline]
 __x64_sys_unshare+0x34/0x40 kernel/fork.c:3351
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

The buggy address belongs to the object at ffff888023c33080
 which belongs to the cache kmalloc-cg-64 of size 64
The buggy address is located 16 bytes inside of
 64-byte region [ffff888023c33080, ffff888023c330c0)

The buggy address belongs to the physical page:
page:ffffea00008f0cc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x23c33
memcg:ffff88802840ce01
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 ffffea0000d25a80 dead000000000003 ffff888017442780
raw: 0000000000000000 0000000080200020 00000001ffffffff ffff88802840ce01
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 9999, tgid 9997 (syz.4.1740), ts 398843811210, free_ts 398748021250
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2559
 prep_new_page mm/page_alloc.c:2566 [inline]
 get_page_from_freelist+0x1a1e/0x1ab0 mm/page_alloc.c:4357
 __alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5657
 alloc_slab_page+0x5d/0x160 mm/slub.c:1799
 allocate_slab mm/slub.c:1944 [inline]
 new_slab+0x87/0x2c0 mm/slub.c:1997
 ___slab_alloc+0xbc6/0x1240 mm/slub.c:3154
 __slab_alloc mm/slub.c:3240 [inline]
 slab_alloc_node mm/slub.c:3325 [inline]
 __kmem_cache_alloc_node+0x1a0/0x260 mm/slub.c:3398
 __do_kmalloc_node mm/slab_common.c:935 [inline]
 __kmalloc_node+0xa0/0x240 mm/slab_common.c:943
 kmalloc_node include/linux/slab.h:589 [inline]
 kvmalloc_node+0x6c/0x180 mm/util.c:581
 kvmalloc include/linux/slab.h:716 [inline]
 kvzalloc include/linux/slab.h:724 [inline]
 allocate_hook_entries_size net/netfilter/core.c:61 [inline]
 nf_hook_entries_grow+0x309/0x730 net/netfilter/core.c:128
 __nf_register_net_hook+0x2c9/0x910 net/netfilter/core.c:423
 nf_register_net_hook+0xae/0x190 net/netfilter/core.c:566
 nf_register_net_hooks+0x40/0x1a0 net/netfilter/core.c:582
 nf_ct_netns_do_get+0x20f/0x5b0 net/netfilter/nf_conntrack_proto.c:500
 nf_ct_netns_inet_get+0x3b/0x150 net/netfilter/nf_conntrack_proto.c:595
 nf_conncount_init+0x123/0x380 net/netfilter/nf_conncount.c:640
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1486 [inline]
 free_pcp_prepare mm/page_alloc.c:1536 [inline]
 free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3413
 free_unref_page_list+0xbb/0x8e0 mm/page_alloc.c:3554
 release_pages+0x1fa6/0x2220 mm/swap.c:1035
 tlb_batch_pages_flush mm/mmu_gather.c:59 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:254 [inline]
 tlb_flush_mmu+0x105/0x220 mm/mmu_gather.c:261
 tlb_finish_mmu+0xbd/0x1c0 mm/mmu_gather.c:361
 exit_mmap+0x384/0x960 mm/mmap.c:3262
 __mmput+0x118/0x3c0 kernel/fork.c:1205
 exit_mm+0x1fe/0x2d0 kernel/exit.c:565
 do_exit+0x905/0x2480 kernel/exit.c:867
 do_group_exit+0x217/0x2d0 kernel/exit.c:1022
 get_signal+0x1272/0x1350 kernel/signal.c:2871
 arch_do_signal_or_restart+0xc4/0x1350 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82

Memory state around the buggy address:
 ffff888023c32f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888023c33000: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff888023c33080: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
                                  ^
 ffff888023c33100: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc
 ffff888023c33180: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================
----------------
Code disassembly (best guess):
   0:	48 c1 e8 03          	shr    $0x3,%rax
   4:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1)
   9:	74 08                	je     0x13
   b:	4c 89 f7             	mov    %r14,%rdi
   e:	e8 ba 6d 2b 00       	call   0x2b6dcd
  13:	4d 8b 3e             	mov    (%r14),%r15
  16:	65 8b 05 48 7f 5a 7e 	mov    %gs:0x7e5a7f48(%rip),%eax        # 0x7e5a7f65
  1d:	41 89 c6             	mov    %eax,%r14d
  20:	4c 89 f6             	mov    %r14,%rsi
  23:	48 81 e6 00 00 f0 00 	and    $0xf00000,%rsi
* 2a:	40 0f 95 c5          	setne  %bpl <-- trapping instruction
  2e:	31 ff                	xor    %edi,%edi
  30:	e8 78 86 da ff       	call   0xffda86ad
  35:	4c 89 f6             	mov    %r14,%rsi
  38:	48 81 e6 00 00 ff 00 	and    $0xff0000,%rsi
  3f:	41                   	rex.B