syzbot

==================================================================
BUG: KASAN: slab-out-of-bounds in __bpf_get_stackid+0x6c9/0x920 kernel/bpf/stackmap.c:274
Write of size 112 at addr ffff888077743a10 by task syz.0.17/4417

CPU: 1 PID: 4417 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <#DB>
 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_6611c23d801ea08d+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_bp_event+0x28c/0x330 kernel/events/core.c:10478
 hw_breakpoint_handler arch/x86/kernel/hw_breakpoint.c:555 [inline]
 hw_breakpoint_exceptions_notify+0x152/0x470 arch/x86/kernel/hw_breakpoint.c:586
 notifier_call_chain kernel/notifier.c:87 [inline]
 atomic_notifier_call_chain+0x17a/0x2b0 kernel/notifier.c:225
 notify_die+0x141/0x1a0 kernel/notifier.c:593
 notify_debug+0x20/0x30 arch/x86/kernel/traps.c:1018
 exc_debug_kernel arch/x86/kernel/traps.c:1075 [inline]
 exc_debug+0xd9/0x130 arch/x86/kernel/traps.c:1175
 asm_exc_debug+0x1a/0x40 arch/x86/include/asm/idtentry.h:648
RIP: 0010:__get_user_nocheck_8+0x9/0x13 arch/x86/lib/getuser.S:160
Code: 90 0f 01 cb 0f ae e8 0f b7 10 31 c0 0f 01 ca c3 90 0f 01 cb 0f ae e8 8b 10 31 c0 0f 01 ca c3 90 90 0f 01 cb 0f ae e8 48 8b 10 <31> c0 0f 01 ca c3 90 0f 01 ca 31 d2 48 c7 c0 f2 ff ff ff c3 00 00
RSP: 0000:ffffc900034a7740 EFLAGS: 00040802
RAX: 0000200000000300 RBX: dffffc0000000000 RCX: ffff88807aab5940
RDX: 00006370692f736e RSI: 0000200000000300 RDI: 00007fffffffeff0
RBP: 0000000000000000 R08: 000000000000007f R09: 0000000000000000
R10: ffffffff8fa0a050 R11: ffffffff8fa0a043 R12: 00000000ffffffff
R13: 0000200000000300 R14: 000000000000007f R15: 00007fffffffeff0
 </#DB>
 <TASK>
 perf_callchain_user+0x55d/0x13c0 arch/x86/events/core.c:2982
 get_perf_callchain+0x39e/0x490 kernel/events/callchain.c:219
 perf_callchain kernel/events/core.c:7512 [inline]
 perf_prepare_sample+0x399/0x2020 kernel/events/core.c:7545
 __perf_event_output kernel/events/core.c:7730 [inline]
 perf_event_output_forward+0x197/0x2f0 kernel/events/core.c:7750
 __perf_event_overflow+0x448/0x610 kernel/events/core.c:9496
 perf_bp_event+0x28c/0x330 kernel/events/core.c:10478
 hw_breakpoint_handler arch/x86/kernel/hw_breakpoint.c:555 [inline]
 hw_breakpoint_exceptions_notify+0x21a/0x470 arch/x86/kernel/hw_breakpoint.c:586
 notifier_call_chain kernel/notifier.c:87 [inline]
 atomic_notifier_call_chain+0x17a/0x2b0 kernel/notifier.c:225
 notify_die+0x141/0x1a0 kernel/notifier.c:593
 notify_debug+0x20/0x30 arch/x86/kernel/traps.c:1018
 exc_debug_user arch/x86/kernel/traps.c:1144 [inline]
 noist_exc_debug+0x73/0x120 arch/x86/kernel/traps.c:1181
 asm_exc_debug+0x2f/0x40 arch/x86/include/asm/idtentry.h:648
RIP: 0033:0x7f7dcb57b43d
Code: 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 89 f8 48 89 fa c5 f9 ef c0 25 ff 0f 00 00 3d e0 0f 00 00 0f 87 27 01 00 00 c5 fd 74 0f <c5> fd d7 c1 85 c0 74 5b f3 0f bc c0 e9 30 01 00 00 66 90 f3 0f bc
RSP: 002b:00007ffc3ddf68f8 EFLAGS: 00000283
RAX: 0000000000000300 RBX: 00007ffc3ddf6e30 RCX: 2f666c65732f636f
RDX: 0000200000000300 RSI: 00007f7dcb65c9c0 RDI: 0000200000000300
RBP: 0000200000000300 R08: 00007ffc3ddf7060 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000073 R14: 00007f7dcb631e03 R15: 00007ffc3ddf6ef0
 </TASK>

Allocated by task 4417:
 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

The buggy address belongs to the object at ffff888077743a00
 which belongs to the cache kmalloc-cg-64 of size 64
The buggy address is located 16 bytes inside of
 64-byte region [ffff888077743a00, ffff888077743a40)

The buggy address belongs to the physical page:
page:ffffea0001ddd0c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x77743
memcg:ffff8880789a9601
flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000200 0000000000000000 dead000000000122 ffff888017442780
raw: 0000000000000000 0000000080200020 00000001ffffffff ffff8880789a9601
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 34, tgid 34 (kworker/u4:2), ts 86796141403, free_ts 85376166699
 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:5643
 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_try_shrink+0x310/0x6d0 net/netfilter/core.c:248
 __nf_unregister_net_hook+0x4e1/0x6e0 net/netfilter/core.c:508
 nf_unregister_net_hook net/netfilter/core.c:-1 [inline]
 nf_unregister_net_hooks+0xc7/0x130 net/netfilter/core.c:601
 nf_ct_netns_do_put net/netfilter/nf_conntrack_proto.c:568 [inline]
 nf_ct_netns_put+0x369/0x510 net/netfilter/nf_conntrack_proto.c:-1
 nf_conncount_destroy+0x3d/0x150 net/netfilter/nf_conncount.c:662
 ovs_ct_limit_exit net/openvswitch/conntrack.c:1919 [inline]
 ovs_ct_exit+0x98/0x200 net/openvswitch/conntrack.c:2322
 ovs_exit_net+0xe9/0x7a0 net/openvswitch/datapath.c:2655
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
 __do_sys_exit_group kernel/exit.c:1033 [inline]
 __se_sys_exit_group kernel/exit.c:1031 [inline]
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1031
 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

Memory state around the buggy address:
 ffff888077743900: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff888077743980: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc
>ffff888077743a00: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
                                  ^
 ffff888077743a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888077743b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
----------------
Code disassembly (best guess):
   0:	90                   	nop
   1:	0f 01 cb             	stac
   4:	0f ae e8             	lfence
   7:	0f b7 10             	movzwl (%rax),%edx
   a:	31 c0                	xor    %eax,%eax
   c:	0f 01 ca             	clac
   f:	c3                   	ret
  10:	90                   	nop
  11:	0f 01 cb             	stac
  14:	0f ae e8             	lfence
  17:	8b 10                	mov    (%rax),%edx
  19:	31 c0                	xor    %eax,%eax
  1b:	0f 01 ca             	clac
  1e:	c3                   	ret
  1f:	90                   	nop
  20:	90                   	nop
  21:	0f 01 cb             	stac
  24:	0f ae e8             	lfence
  27:	48 8b 10             	mov    (%rax),%rdx
* 2a:	31 c0                	xor    %eax,%eax <-- trapping instruction
  2c:	0f 01 ca             	clac
  2f:	c3                   	ret
  30:	90                   	nop
  31:	0f 01 ca             	clac
  34:	31 d2                	xor    %edx,%edx
  36:	48 c7 c0 f2 ff ff ff 	mov    $0xfffffffffffffff2,%rax
  3d:	c3                   	ret