================================================================== BUG: KASAN: slab-out-of-bounds in __bpf_get_stackid+0x6bf/0x900 kernel/bpf/stackmap.c:271 Write of size 48 at addr ffff888044004010 by task syz.1.10053/5805 CPU: 0 PID: 5805 Comm: syz.1.10053 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xa8/0x210 mm/kasan/report.c:468 kasan_report+0x117/0x150 mm/kasan/report.c:581 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x241/0x290 mm/kasan/generic.c:187 __asan_memcpy+0x40/0x70 mm/kasan/shadow.c:106 __bpf_get_stackid+0x6bf/0x900 kernel/bpf/stackmap.c:271 ____bpf_get_stackid_pe kernel/bpf/stackmap.c:362 [inline] bpf_get_stackid_pe+0x343/0x410 kernel/bpf/stackmap.c:331 bpf_prog_a448e89f4c9ad9d1+0x30/0x4a bpf_dispatcher_nop_func include/linux/bpf.h:1224 [inline] __bpf_prog_run include/linux/filter.h:616 [inline] bpf_prog_run include/linux/filter.h:623 [inline] bpf_overflow_handler+0x1fc/0x510 kernel/events/core.c:10547 __perf_event_overflow+0x447/0x630 kernel/events/core.c:9718 perf_swevent_overflow kernel/events/core.c:9794 [inline] perf_swevent_event+0x324/0x630 kernel/events/core.c:-1 do_perf_sw_event kernel/events/core.c:9935 [inline] ___perf_sw_event+0x4a7/0x730 kernel/events/core.c:9966 __perf_sw_event+0x139/0x270 kernel/events/core.c:9978 perf_sw_event include/linux/perf_event.h:1442 [inline] do_user_addr_fault+0x123e/0x12c0 arch/x86/mm/fault.c:1278 handle_page_fault arch/x86/mm/fault.c:1463 [inline] exc_page_fault+0x64/0x100 arch/x86/mm/fault.c:1516 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0010:__get_user_4+0x11/0x20 arch/x86/lib/getuser.S:81 Code: 48 c1 fa 3f 48 09 d0 0f 01 cb 0f b7 10 31 c0 0f 01 ca c3 90 90 90 90 90 90 f3 0f 1e fa 48 89 c2 48 c1 fa 3f 48 09 d0 0f 01 cb <8b> 10 31 c0 0f 01 ca c3 90 90 90 90 90 90 90 f3 0f 1e fa 48 89 c2 RSP: 0018:ffffc9000457fce0 EFLAGS: 00050202 RAX: 0000000000000004 RBX: ffffc9000457fde0 RCX: ccf6e780310fc800 RDX: 0000000000000000 RSI: ffffffff8acadae0 RDI: ffffffff8b1c85a0 RBP: ffffc9000457ff10 R08: ffffffff8e8aeeef R09: 1ffffffff1d15ddd R10: dffffc0000000000 R11: fffffbfff1d15dde R12: 0000000000000000 R13: 0000000000000004 R14: ffffc9000457fde0 R15: 0000000000000000 perf_copy_attr+0x45/0x840 kernel/events/core.c:12279 __do_sys_perf_event_open kernel/events/core.c:12590 [inline] __se_sys_perf_event_open+0x11b/0x1c50 kernel/events/core.c:12567 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fe156f9c799 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:00007fe157ebc028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007fe157215fa0 RCX: 00007fe156f9c799 RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fe157032c99 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe157216038 R14: 00007fe157215fa0 R15: 00007ffdc67dae18 Allocated by task 5805: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:384 kasan_kmalloc include/linux/kasan.h:198 [inline] __do_kmalloc_node mm/slab_common.c:1007 [inline] __kmalloc_node+0xb4/0x230 mm/slab_common.c:1014 kmalloc_node include/linux/slab.h:620 [inline] __bpf_map_area_alloc kernel/bpf/syscall.c:303 [inline] bpf_map_area_alloc+0x5e/0x110 kernel/bpf/syscall.c:316 prealloc_elems_and_freelist+0x86/0x1c0 kernel/bpf/stackmap.c:51 stack_map_alloc+0x33a/0x4c0 kernel/bpf/stackmap.c:114 map_create+0x877/0x12f0 kernel/bpf/syscall.c:1247 __sys_bpf+0x651/0x890 kernel/bpf/syscall.c:5458 __do_sys_bpf kernel/bpf/syscall.c:5580 [inline] __se_sys_bpf kernel/bpf/syscall.c:5578 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5578 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492 __call_rcu_common kernel/rcu/tree.c:2721 [inline] call_rcu+0x153/0x950 kernel/rcu/tree.c:2837 nf_hook_entries_free net/netfilter/core.c:88 [inline] __nf_register_net_hook+0x788/0x910 net/netfilter/core.c:457 nf_register_net_hook+0xb2/0x190 net/netfilter/core.c:578 nf_register_net_hooks+0x44/0x1b0 net/netfilter/core.c:594 nf_ct_netns_do_get+0x3c0/0x5c0 net/netfilter/nf_conntrack_proto.c:457 nf_ct_netns_inet_get+0x1f/0x150 net/netfilter/nf_conntrack_proto.c:566 nf_conncount_init+0x127/0x380 net/netfilter/nf_conncount.c:640 ovs_ct_limit_init net/openvswitch/conntrack.c:1580 [inline] ovs_ct_init+0x316/0x490 net/openvswitch/conntrack.c:1989 ovs_init_net+0x1e6/0x250 net/openvswitch/datapath.c:2644 ops_init+0x397/0x640 net/core/net_namespace.c:139 setup_net+0x3b6/0xa30 net/core/net_namespace.c:343 copy_net_ns+0x36d/0x5e0 net/core/net_namespace.c:520 create_new_namespaces+0x3d3/0x6f0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x11a/0x160 kernel/nsproxy.c:228 ksys_unshare+0x4ce/0x8b0 kernel/fork.c:3439 __do_sys_unshare kernel/fork.c:3510 [inline] __se_sys_unshare kernel/fork.c:3508 [inline] __x64_sys_unshare+0x38/0x40 kernel/fork.c:3508 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff888044004000 which belongs to the cache kmalloc-cg-64 of size 64 The buggy address is located 16 bytes inside of allocated 40-byte region [ffff888044004000, ffff888044004028) The buggy address belongs to the physical page: page:ffffea0001100100 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x44004 memcg:ffff88802fba1a01 anon flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000800 ffff888017c4da00 ffffea0000907140 0000000000000005 raw: 0000000000000000 0000000080200020 00000001ffffffff ffff88802fba1a01 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 29788, tgid 29788 (syz-executor), ts 2454859958083, free_ts 2454824462747 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1581 prep_new_page mm/page_alloc.c:1588 [inline] get_page_from_freelist+0x1951/0x19e0 mm/page_alloc.c:3220 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4500 alloc_slab_page+0x5d/0x160 mm/slub.c:1881 allocate_slab mm/slub.c:2028 [inline] new_slab+0x87/0x2d0 mm/slub.c:2081 ___slab_alloc+0xc5d/0x12f0 mm/slub.c:3253 __slab_alloc mm/slub.c:3339 [inline] __slab_alloc_node mm/slub.c:3392 [inline] slab_alloc_node mm/slub.c:3485 [inline] __kmem_cache_alloc_node+0x19e/0x250 mm/slub.c:3534 kmalloc_trace+0x2a/0xe0 mm/slab_common.c:1098 kmalloc include/linux/slab.h:600 [inline] alloc_fdtable+0xca/0x2c0 fs/file.c:147 dup_fd+0x786/0xa50 fs/file.c:346 copy_files+0xc3/0x120 kernel/fork.c:1794 copy_process+0x15ab/0x3d80 kernel/fork.c:2494 kernel_clone+0x24b/0x8a0 kernel/fork.c:2914 __do_sys_clone kernel/fork.c:3057 [inline] __se_sys_clone kernel/fork.c:3041 [inline] __x64_sys_clone+0x1b7/0x230 kernel/fork.c:3041 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 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:1181 [inline] free_unref_page_prepare+0x7b2/0x8c0 mm/page_alloc.c:2365 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2458 vfree+0x1a6/0x320 mm/vmalloc.c:2868 delayed_vfree_work+0x55/0x80 mm/vmalloc.c:2788 process_one_work kernel/workqueue.c:2653 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Memory state around the buggy address: ffff888044003f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888044003f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888044004000: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc ^ ffff888044004080: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888044004100: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess): 0: 48 c1 fa 3f sar $0x3f,%rdx 4: 48 09 d0 or %rdx,%rax 7: 0f 01 cb stac a: 0f b7 10 movzwl (%rax),%edx d: 31 c0 xor %eax,%eax f: 0f 01 ca clac 12: c3 ret 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: 90 nop 19: f3 0f 1e fa endbr64 1d: 48 89 c2 mov %rax,%rdx 20: 48 c1 fa 3f sar $0x3f,%rdx 24: 48 09 d0 or %rdx,%rax 27: 0f 01 cb stac * 2a: 8b 10 mov (%rax),%edx <-- trapping instruction 2c: 31 c0 xor %eax,%eax 2e: 0f 01 ca clac 31: c3 ret 32: 90 nop 33: 90 nop 34: 90 nop 35: 90 nop 36: 90 nop 37: 90 nop 38: 90 nop 39: f3 0f 1e fa endbr64 3d: 48 89 c2 mov %rax,%rdx