================================================================== BUG: KASAN: slab-out-of-bounds in stack_map_get_build_id_offset+0x833/0x9b0 kernel/bpf/stackmap.c:147 Write of size 4 at addr ffff888131afed10 by task syz.3.937/4052 CPU: 0 PID: 4052 Comm: syz.3.937 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: __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 __asan_report_store4_noabort+0x17/0x20 mm/kasan/report_generic.c:355 stack_map_get_build_id_offset+0x833/0x9b0 kernel/bpf/stackmap.c:147 __bpf_get_stackid+0x5ac/0x960 kernel/bpf/stackmap.c:250 ____bpf_get_stackid_pe kernel/bpf/stackmap.c:365 [inline] bpf_get_stackid_pe+0x2ee/0x400 kernel/bpf/stackmap.c:334 bpf_prog_43b50326510579ba+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+0x3c7/0x5e0 kernel/events/core.c:10273 __perf_event_overflow+0x458/0x640 kernel/events/core.c:9448 perf_swevent_overflow kernel/events/core.c:9531 [inline] perf_swevent_event+0x243/0x440 kernel/events/core.c:9582 do_perf_sw_event kernel/events/core.c:9695 [inline] ___perf_sw_event+0x3bf/0x500 kernel/events/core.c:9726 __perf_sw_event+0x134/0x270 kernel/events/core.c:9738 perf_sw_event include/linux/perf_event.h:1250 [inline] do_user_addr_fault+0xfe9/0x1030 arch/x86/mm/fault.c:1285 handle_page_fault arch/x86/mm/fault.c:1464 [inline] exc_page_fault+0x51/0xb0 arch/x86/mm/fault.c:1517 asm_exc_page_fault+0x27/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0010:copy_user_short_string+0xd/0x40 arch/x86/lib/copy_user_64.S:233 Code: 74 0a 89 d1 f3 a4 89 c8 0f 01 ca c3 89 d0 0f 01 ca c3 01 ca eb e7 90 90 90 90 90 90 90 89 d1 83 e2 07 c1 e9 03 74 12 4c 8b 06 <4c> 89 07 48 8d 76 08 48 8d 7f 08 ff c9 75 ee 21 d2 74 10 89 d1 8a RSP: 0018:ffffc9000ea47298 EFLAGS: 00050202 RAX: ffffffff82692e01 RBX: 000000000000000b RCX: 0000000000000001 RDX: 0000000000000003 RSI: ffff88811323066c RDI: 000000000000cf3d RBP: ffffc9000ea472c0 R08: 40203023636e7566 R09: 1ffff110226460ce R10: dffffc0000000000 R11: ffffed10226460cf R12: 00007fffffffeff5 R13: 000000000000000b R14: 000000000000cf3d R15: ffff88811323066c copy_to_user include/linux/uaccess.h:169 [inline] bpf_verifier_vlog+0x179/0x390 kernel/bpf/log.c:34 verbose+0x1f0/0x2b0 kernel/bpf/verifier.c:303 add_subprog_and_kfunc kernel/bpf/verifier.c:2165 [inline] bpf_check+0x2f1b/0x10e90 kernel/bpf/verifier.c:15549 bpf_prog_load+0x10f4/0x1670 kernel/bpf/syscall.c:2624 __sys_bpf+0x57b/0x850 kernel/bpf/syscall.c:5006 __do_sys_bpf kernel/bpf/syscall.c:5110 [inline] __se_sys_bpf kernel/bpf/syscall.c:5108 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5108 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 RIP: 0033:0x7ff92879e159 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:00007ff92967a028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007ff928a25fa0 RCX: 00007ff92879e159 RDX: 0000000000000023 RSI: 000020000000e000 RDI: 0000000000000005 RBP: 00007ff92883506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff928a26038 R14: 00007ff928a25fa0 R15: 00007ffffb6f8848 Allocated by task 4052: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_alloc_info+0x1f/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+0x398/0x520 kernel/bpf/stackmap.c:117 find_and_alloc_map kernel/bpf/syscall.c:133 [inline] map_create+0x467/0xcf0 kernel/bpf/syscall.c:1126 __sys_bpf+0x34e/0x850 kernel/bpf/syscall.c:4988 __do_sys_bpf kernel/bpf/syscall.c:5110 [inline] __se_sys_bpf kernel/bpf/syscall.c:5108 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5108 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 Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xb6/0xc0 mm/kasan/generic.c:486 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:496 __call_rcu_common kernel/rcu/tree.c:2807 [inline] call_rcu+0xcf/0xf50 kernel/rcu/tree.c:2926 fib6_info_release include/net/ip6_fib.h:350 [inline] ip6_route_add+0xe4/0x130 net/ipv6/route.c:3900 addrconf_prefix_route net/ipv6/addrconf.c:2466 [inline] add_v4_addrs+0x809/0xb20 net/ipv6/addrconf.c:3237 addrconf_sit_config net/ipv6/addrconf.c:3486 [inline] addrconf_init_auto_addrs+0x3d6/0xbc0 net/ipv6/addrconf.c:3524 addrconf_notify+0x7fe/0xe30 net/ipv6/addrconf.c:3711 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xa1/0x110 kernel/notifier.c:455 call_netdevice_notifiers_info net/core/dev.c:2022 [inline] call_netdevice_notifiers_extack net/core/dev.c:2060 [inline] call_netdevice_notifiers net/core/dev.c:2074 [inline] __dev_notify_flags+0x2f4/0x5b0 net/core/dev.c:8730 dev_change_flags+0xe3/0x1a0 net/core/dev.c:8768 dev_ifsioc+0x130/0xd90 net/core/dev_ioctl.c:326 dev_ioctl+0x53c/0xcf0 net/core/dev_ioctl.c:572 sock_do_ioctl+0x252/0x330 net/socket.c:1206 sock_ioctl+0x475/0x700 net/socket.c:1311 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 The buggy address belongs to the object at ffff888131afec00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 272 bytes inside of 512-byte region [ffff888131afec00, ffff888131afee00) The buggy address belongs to the physical page: page:ffffea0004c6bf00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x131afc head:ffffea0004c6bf00 order:2 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head|zone=1) raw: 4000000000010200 dead000000000100 dead000000000122 ffff888100042f00 raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0x52a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 59, tgid 59 (kworker/1:2), ts 25423296466, free_ts 0 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2673 prep_new_page+0x1c/0x110 mm/page_alloc.c:2680 get_page_from_freelist+0x2ca9/0x2d20 mm/page_alloc.c:4587 __alloc_pages+0x1fa/0x610 mm/page_alloc.c:5931 alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1 allocate_slab mm/slub.c:1967 [inline] new_slab+0x98/0x3e0 mm/slub.c:2020 ___slab_alloc+0x70f/0xb70 mm/slub.c:3177 __slab_alloc+0x5e/0xa0 mm/slub.c:3263 slab_alloc_node mm/slub.c:3348 [inline] __kmem_cache_alloc_node+0x204/0x2d0 mm/slub.c:3423 kmalloc_trace+0x29/0xb0 mm/slab_common.c:1028 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] br_multicast_new_port_group+0x69/0x540 net/bridge/br_multicast.c:1285 __br_multicast_add_group+0x538/0x960 net/bridge/br_multicast.c:1383 br_multicast_add_group net/bridge/br_multicast.c:1414 [inline] br_ip6_multicast_add_group net/bridge/br_multicast.c:1466 [inline] br_ip6_multicast_mld2_report net/bridge/br_multicast.c:2863 [inline] br_multicast_ipv6_rcv net/bridge/br_multicast.c:3801 [inline] br_multicast_rcv+0x402d/0x76c0 net/bridge/br_multicast.c:3859 br_handle_frame_finish+0x57f/0x1420 net/bridge/br_input.c:136 nf_hook_bridge_pre net/bridge/br_input.c:282 [inline] br_handle_frame+0x6c6/0x10d0 net/bridge/br_input.c:406 __netif_receive_skb_core+0xf60/0x3580 net/core/dev.c:5529 page_owner free stack trace missing Memory state around the buggy address: ffff888131afec00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888131afec80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888131afed00: 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888131afed80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888131afee00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess): 0: 74 0a je 0xc 2: 89 d1 mov %edx,%ecx 4: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) 6: 89 c8 mov %ecx,%eax 8: 0f 01 ca clac b: c3 ret c: 89 d0 mov %edx,%eax e: 0f 01 ca clac 11: c3 ret 12: 01 ca add %ecx,%edx 14: eb e7 jmp 0xfffffffd 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: 90 nop 1b: 90 nop 1c: 90 nop 1d: 89 d1 mov %edx,%ecx 1f: 83 e2 07 and $0x7,%edx 22: c1 e9 03 shr $0x3,%ecx 25: 74 12 je 0x39 27: 4c 8b 06 mov (%rsi),%r8 * 2a: 4c 89 07 mov %r8,(%rdi) <-- trapping instruction 2d: 48 8d 76 08 lea 0x8(%rsi),%rsi 31: 48 8d 7f 08 lea 0x8(%rdi),%rdi 35: ff c9 dec %ecx 37: 75 ee jne 0x27 39: 21 d2 and %edx,%edx 3b: 74 10 je 0x4d 3d: 89 d1 mov %edx,%ecx 3f: 8a .byte 0x8a