================================================================== BUG: KASAN: slab-out-of-bounds in __bpf_get_stackid+0x6c9/0x920 kernel/bpf/stackmap.c:274 Write of size 56 at addr ffff88802676d110 by task syz.4.11317/6834 CPU: 1 PID: 6834 Comm: syz.4.11317 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: 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_ee9fdca00c0e1e15+0x28/0x3d 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+0x50b/0x790 kernel/events/core.c:10321 __perf_event_overflow+0x457/0x630 kernel/events/core.c:9496 perf_swevent_overflow kernel/events/core.c:9579 [inline] perf_swevent_event+0x315/0x570 kernel/events/core.c:9630 do_perf_sw_event kernel/events/core.c:9743 [inline] ___perf_sw_event+0x498/0x6d0 kernel/events/core.c:9774 __perf_sw_event+0x135/0x260 kernel/events/core.c:9786 perf_sw_event include/linux/perf_event.h:1254 [inline] do_user_addr_fault+0x497/0xb20 arch/x86/mm/fault.c:1284 handle_page_fault arch/x86/mm/fault.c:1429 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1482 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0010:do_strncpy_from_user lib/strncpy_from_user.c:41 [inline] RIP: 0010:strncpy_from_user+0x148/0x340 lib/strncpy_from_user.c:139 Code: 00 00 00 4c 89 e6 e8 87 2d 45 fd 49 83 fc 07 0f 86 9a 00 00 00 4c 89 74 24 08 48 c7 44 24 10 f8 ff ff ff 45 31 ed 4c 89 3c 24 <4f> 8b 3c 2f 48 b8 ff fe fe fe fe fe fe fe 49 8d 2c 07 4d 89 fe 49 RSP: 0018:ffffc9000e00fb50 EFLAGS: 00050246 RAX: ffffffff843d0a49 RBX: ffffc9000e00fc70 RCX: ffff88802cef8000 RDX: 0000000000000002 RSI: 000000000000007f RDI: 0000000000000007 RBP: 0000000000000000 R08: ffff88802cef8000 R09: 0000000000000003 R10: 0000000000000002 R11: 0000000000000002 R12: 000000000000007f R13: 0000000000000000 R14: 000000000000007f R15: 0000000000000000 strncpy_from_bpfptr include/linux/bpfptr.h:85 [inline] bpf_prog_load+0x200/0x1530 kernel/bpf/syscall.c:2535 __sys_bpf+0x5b8/0x780 kernel/bpf/syscall.c:5032 __do_sys_bpf kernel/bpf/syscall.c:5136 [inline] __se_sys_bpf kernel/bpf/syscall.c:5134 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5134 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: 0033:0x7f9354b9df99 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:00007f9355a26028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f9354e25fa0 RCX: 00007f9354b9df99 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00007f9354c34ec4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9354e26038 R14: 00007f9354e25fa0 R15: 00007fffa8075388 Allocated by task 6834: 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+0xb2/0x240 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+0x386/0x510 kernel/bpf/stackmap.c:117 find_and_alloc_map kernel/bpf/syscall.c:133 [inline] map_create+0x524/0xff0 kernel/bpf/syscall.c:1149 __sys_bpf+0x38b/0x780 kernel/bpf/syscall.c:5014 __do_sys_bpf kernel/bpf/syscall.c:5136 [inline] __se_sys_bpf kernel/bpf/syscall.c:5134 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5134 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/0x950 kernel/rcu/tree.c:2849 nf_nat_unregister_fn+0x1d9/0x360 net/netfilter/nf_nat_core.c:1107 ip6t_nat_unregister_lookups net/ipv6/netfilter/ip6table_nat.c:103 [inline] ip6table_nat_net_pre_exit+0x50/0x90 net/ipv6/netfilter/ip6table_nat.c:133 ops_pre_exit_list net/core/net_namespace.c:162 [inline] cleanup_net+0x58e/0xba0 net/core/net_namespace.c:620 process_one_work+0x8ab/0x1160 kernel/workqueue.c:2292 worker_thread+0xaf5/0x12a0 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/0x950 kernel/rcu/tree.c:2849 nf_hook_entries_free net/netfilter/core.c:88 [inline] __nf_register_net_hook+0x787/0x910 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+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:639 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:2645 ops_init+0x360/0x5e0 net/core/net_namespace.c:138 setup_net+0x4f2/0xbd0 net/core/net_namespace.c:336 copy_net_ns+0x33e/0x5b0 net/core/net_namespace.c:508 create_new_namespaces+0x3ce/0x700 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x116/0x160 kernel/nsproxy.c:226 ksys_unshare+0x4f6/0x8e0 kernel/fork.c:3285 __do_sys_unshare kernel/fork.c:3359 [inline] __se_sys_unshare kernel/fork.c:3357 [inline] __x64_sys_unshare+0x34/0x40 kernel/fork.c:3357 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 ffff88802676d100 which belongs to the cache kmalloc-cg-64 of size 64 The buggy address is located 16 bytes inside of 64-byte region [ffff88802676d100, ffff88802676d140) The buggy address belongs to the physical page: page:ffffea000099db40 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88802676d300 pfn:0x2676d memcg:ffff88807e58e801 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea0001c9edc0 dead000000000007 ffff888017442780 raw: ffff88802676d300 000000008020001d 00000001ffffffff ffff88807e58e801 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 4273, tgid 4273 (syz-executor), ts 115915394784, free_ts 115914987271 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2560 prep_new_page mm/page_alloc.c:2567 [inline] get_page_from_freelist+0x206b/0x2180 mm/page_alloc.c:4358 __alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5658 alloc_slab_page+0x5d/0x180 mm/slub.c:1799 allocate_slab mm/slub.c:1944 [inline] new_slab+0x87/0x2d0 mm/slub.c:1997 ___slab_alloc+0xbc5/0x1240 mm/slub.c:3154 __slab_alloc mm/slub.c:3240 [inline] slab_alloc_node mm/slub.c:3325 [inline] __kmem_cache_alloc_node+0x126/0x270 mm/slub.c:3398 kmalloc_trace+0x26/0xe0 mm/slab_common.c:1026 kmalloc include/linux/slab.h:563 [inline] alloc_fdtable+0xca/0x2c0 fs/file.c:147 dup_fd+0x743/0xa20 fs/file.c:346 copy_files+0x72/0xe0 kernel/fork.c:1643 copy_process+0x1862/0x40c0 kernel/fork.c:2346 kernel_clone+0x24b/0x900 kernel/fork.c:2765 __do_sys_clone kernel/fork.c:2906 [inline] __se_sys_clone kernel/fork.c:2890 [inline] __x64_sys_clone+0x1a7/0x220 kernel/fork.c:2890 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 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1487 [inline] free_pcp_prepare mm/page_alloc.c:1537 [inline] free_unref_page_prepare+0x8e5/0x9e0 mm/page_alloc.c:3414 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3509 __vunmap+0x874/0xa40 mm/vmalloc.c:2726 __do_replace+0x86d/0x980 net/ipv6/netfilter/ip6_tables.c:1107 do_replace net/ipv6/netfilter/ip6_tables.c:1158 [inline] do_ip6t_set_ctl+0xb3d/0xe10 net/ipv6/netfilter/ip6_tables.c:1643 nf_setsockopt+0x25f/0x280 net/netfilter/nf_sockopt.c:101 __sys_setsockopt+0x2bf/0x3d0 net/socket.c:2288 __do_sys_setsockopt net/socket.c:2299 [inline] __se_sys_setsockopt net/socket.c:2296 [inline] __x64_sys_setsockopt+0xb1/0xc0 net/socket.c:2296 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: ffff88802676d000: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff88802676d080: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff88802676d100: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc ^ ffff88802676d180: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff88802676d200: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 00 4c 89 e6 add %cl,-0x1a(%rcx,%rcx,4) 6: e8 87 2d 45 fd call 0xfd452d92 b: 49 83 fc 07 cmp $0x7,%r12 f: 0f 86 9a 00 00 00 jbe 0xaf 15: 4c 89 74 24 08 mov %r14,0x8(%rsp) 1a: 48 c7 44 24 10 f8 ff movq $0xfffffffffffffff8,0x10(%rsp) 21: ff ff 23: 45 31 ed xor %r13d,%r13d 26: 4c 89 3c 24 mov %r15,(%rsp) * 2a: 4f 8b 3c 2f mov (%r15,%r13,1),%r15 <-- trapping instruction 2e: 48 b8 ff fe fe fe fe movabs $0xfefefefefefefeff,%rax 35: fe fe fe 38: 49 8d 2c 07 lea (%r15,%rax,1),%rbp 3c: 4d 89 fe mov %r15,%r14 3f: 49 rex.WB