==================================================================
BUG: KASAN: slab-out-of-bounds in __bpf_get_stackid+0x6fa/0x960 kernel/bpf/stackmap.c:274
Write of size 80 at addr ffff8881323c0610 by task syz.3.197/1031

CPU: 0 PID: 1031 Comm: syz.3.197 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Call Trace:
 <IRQ>
 __dump_stack+0x21/0x24 lib/dump_stack.c:88
 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106
 print_address_description+0x71/0x200 mm/kasan/report.c:316
 print_report+0x4a/0x60 mm/kasan/report.c:420
 kasan_report+0x122/0x150 mm/kasan/report.c:524
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x249/0x2a0 mm/kasan/generic.c:189
 memcpy+0x44/0x70 mm/kasan/shadow.c:66
 __bpf_get_stackid+0x6fa/0x960 kernel/bpf/stackmap.c:274
 ____bpf_get_stackid_pe kernel/bpf/stackmap.c:365 [inline]
 bpf_get_stackid_pe+0x2ee/0x400 kernel/bpf/stackmap.c:334
 bpf_prog_6611c23d801ea08d+0x21/0x36
 bpf_dispatcher_nop_func include/linux/bpf.h:987 [inline]
 __bpf_prog_run include/linux/filter.h:607 [inline]
 bpf_prog_run include/linux/filter.h:614 [inline]
 bpf_overflow_handler+0x3d0/0x5e0 kernel/events/core.c:10238
 __perf_event_overflow+0x437/0x620 kernel/events/core.c:9448
 perf_swevent_hrtimer+0x400/0x5b0 kernel/events/core.c:10879
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x3d5/0xa00 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x3c7/0x8c0 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline]
 __sysvec_apic_timer_interrupt+0x11e/0x440 arch/x86/kernel/apic/apic.c:1124
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:85 [inline]
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:102 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline]
RIP: 0010:kasan_check_range+0x89/0x2a0 mm/kasan/generic.c:189
Code: 49 c1 e9 03 4b 8d 1c 29 49 89 dc 4d 29 dc 49 83 fc 10 7f 29 4d 85 e4 0f 84 45 01 00 00 4c 89 cb 48 f7 d3 4c 01 f3 41 80 3b 00 <0f> 85 95 01 00 00 49 ff c3 48 ff c3 75 ee e9 25 01 00 00 45 89 df
RSP: 0018:ffffc90000f3faf8 EFLAGS: 00000246
RAX: f3f3f3f8f1f1f101 RBX: ffffffffffffffff RCX: ffffffff84ff1a52
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff8881332f1810
RBP: ffffc90000f3fb20 R08: ffff8881332f1817 R09: 1ffff1102665e302
R10: dffffc0000000000 R11: ffffed102665e302 R12: 0000000000000001
R13: dffffc0000000001 R14: 1ffff1102665e302 R15: ffffc90000f3fb60
 __kasan_check_write+0x14/0x20 mm/kasan/shadow.c:37
 instrument_atomic_read_write include/linux/instrumented.h:102 [inline]
 atomic_long_try_cmpxchg_release include/linux/atomic/atomic-instrumented.h:1788 [inline]
 __mutex_unlock_fast kernel/locking/mutex.c:188 [inline]
 mutex_unlock+0x82/0x230 kernel/locking/mutex.c:560
 perf_event_ctx_unlock kernel/events/core.c:1321 [inline]
 perf_ioctl+0x1406/0x1e70 kernel/events/core.c:5838
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0x12f/0x1b0 fs/ioctl.c:856
 __x64_sys_ioctl+0x7b/0x90 fs/ioctl.c:856
 x64_sys_call+0x58b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:17
 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
RIP: 0033:0x7f8ae799aeb9
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:00007f8ae87a0028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f8ae7c15fa0 RCX: 00007f8ae799aeb9
RDX: 0000000000000004 RSI: 0000000040042408 RDI: 0000000000000005
RBP: 00007f8ae7a08c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8ae7c16038 R14: 00007f8ae7c15fa0 R15: 00007ffe50e25308
 </TASK>

Allocated by task 1031:
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
 kasan_save_alloc_info+0x25/0x30 mm/kasan/generic.c:505
 ____kasan_kmalloc mm/kasan/common.c:380 [inline]
 __kasan_kmalloc+0x95/0xb0 mm/kasan/common.c:389
 kasan_kmalloc include/linux/kasan.h:212 [inline]
 __do_kmalloc_node mm/slab_common.c:938 [inline]
 __kmalloc_node+0xb2/0x1e0 mm/slab_common.c:945
 kmalloc_node include/linux/slab.h:589 [inline]
 __bpf_map_area_alloc kernel/bpf/syscall.c:328 [inline]
 bpf_map_area_alloc+0x4b/0xe0 kernel/bpf/syscall.c:341
 prealloc_elems_and_freelist+0x8a/0x1e0 kernel/bpf/stackmap.c:51
 stack_map_alloc+0x3a7/0x530 kernel/bpf/stackmap.c:117
 find_and_alloc_map kernel/bpf/syscall.c:133 [inline]
 map_create+0x49c/0xd80 kernel/bpf/syscall.c:1126
 __sys_bpf+0x34e/0x850 kernel/bpf/syscall.c:4987
 __do_sys_bpf kernel/bpf/syscall.c:5109 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5107 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5107
 x64_sys_call+0x488/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:322
 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 ffff8881323c0600
 which belongs to the cache kmalloc-64 of size 64
The buggy address is located 16 bytes inside of
 64-byte region [ffff8881323c0600, ffff8881323c0640)

The buggy address belongs to the physical page:
page:ffffea0004c8f000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1323c0
flags: 0x4000000000000200(slab|zone=1)
raw: 4000000000000200 ffffea0004cc20c0 dead000000000002 ffff888100042780
raw: 0000000000000000 0000000080200020 00000001ffffffff 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 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 549, tgid 548 (syz.2.63), ts 34940269521, free_ts 34938812339
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2643
 prep_new_page+0x1c/0x110 mm/page_alloc.c:2650
 get_page_from_freelist+0x2d12/0x2d80 mm/page_alloc.c:4554
 __alloc_pages+0x1d9/0x480 mm/page_alloc.c:5868
 alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1
 allocate_slab mm/slub.c:1967 [inline]
 new_slab+0x98/0x3d0 mm/slub.c:2020
 ___slab_alloc+0x6bd/0xb20 mm/slub.c:3177
 __slab_alloc+0x5e/0xa0 mm/slub.c:3263
 slab_alloc_node mm/slub.c:3348 [inline]
 __kmem_cache_alloc_node+0x203/0x2c0 mm/slub.c:3423
 __do_kmalloc_node mm/slab_common.c:937 [inline]
 __kmalloc_node_track_caller+0xa0/0x1e0 mm/slab_common.c:958
 kmemdup+0x2b/0x60 mm/util.c:134
 kmemdup include/linux/fortify-string.h:585 [inline]
 fib_notifier_ops_register+0x2e/0x270 net/core/fib_notifier.c:148
 ip6mr_notifier_init net/ipv6/ip6mr.c:1308 [inline]
 ip6mr_net_init+0x53/0x420 net/ipv6/ip6mr.c:1328
 ops_init+0x1c8/0x4a0 net/core/net_namespace.c:138
 setup_net+0x4b4/0xcc0 net/core/net_namespace.c:335
 copy_net_ns+0x355/0x5c0 net/core/net_namespace.c:481
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 free_pages_prepare mm/page_alloc.c:1551 [inline]
 free_pcp_prepare mm/page_alloc.c:1625 [inline]
 free_unref_page_prepare+0x742/0x750 mm/page_alloc.c:3589
 free_unref_page+0x95/0x540 mm/page_alloc.c:3687
 free_the_page mm/page_alloc.c:836 [inline]
 __free_pages+0x67/0x100 mm/page_alloc.c:5957
 __vunmap+0x9c0/0xb80 mm/vmalloc.c:2739
 __vfree mm/vmalloc.c:2788 [inline]
 vfree+0x61/0x90 mm/vmalloc.c:2819
 kvfree+0x26/0x40 mm/util.c:637
 bpf_map_area_free+0x15/0x20 kernel/bpf/syscall.c:351
 queue_stack_map_free+0x15/0x20 kernel/bpf/queue_stack_maps.c:95
 bpf_map_free_deferred+0x105/0x1c0 kernel/bpf/syscall.c:637
 process_one_work+0x71f/0xc40 kernel/workqueue.c:2302
 worker_thread+0xa29/0x11e0 kernel/workqueue.c:2449
 kthread+0x281/0x320 kernel/kthread.c:386
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

Memory state around the buggy address:
 ffff8881323c0500: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff8881323c0580: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff8881323c0600: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
                                  ^
 ffff8881323c0680: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc
 ffff8881323c0700: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================
----------------
Code disassembly (best guess):
   0:	49 c1 e9 03          	shr    $0x3,%r9
   4:	4b 8d 1c 29          	lea    (%r9,%r13,1),%rbx
   8:	49 89 dc             	mov    %rbx,%r12
   b:	4d 29 dc             	sub    %r11,%r12
   e:	49 83 fc 10          	cmp    $0x10,%r12
  12:	7f 29                	jg     0x3d
  14:	4d 85 e4             	test   %r12,%r12
  17:	0f 84 45 01 00 00    	je     0x162
  1d:	4c 89 cb             	mov    %r9,%rbx
  20:	48 f7 d3             	not    %rbx
  23:	4c 01 f3             	add    %r14,%rbx
  26:	41 80 3b 00          	cmpb   $0x0,(%r11)
* 2a:	0f 85 95 01 00 00    	jne    0x1c5 <-- trapping instruction
  30:	49 ff c3             	inc    %r11
  33:	48 ff c3             	inc    %rbx
  36:	75 ee                	jne    0x26
  38:	e9 25 01 00 00       	jmp    0x162
  3d:	45 89 df             	mov    %r11d,%r15d