================================================================== BUG: KASAN: slab-out-of-bounds in __bpf_get_stackid+0x6fa/0x960 kernel/bpf/stackmap.c:274 Write of size 56 at addr ffff888131c92690 by task syz.0.247/1144 CPU: 1 PID: 1144 Comm: syz.0.247 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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 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_a448e89f4c9ad9d1+0x28/0x42 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:10273 __perf_event_overflow+0x437/0x620 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/0x4f0 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+0xffb/0x1050 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:__get_user_4+0x1c/0x30 arch/x86/lib/getuser.S:85 Code: 01 ca c3 90 90 90 90 90 90 90 90 90 90 90 48 ba fd ef ff ff ff 7f 00 00 48 39 d0 0f 83 90 00 00 00 48 19 d2 48 21 d0 0f 01 cb <8b> 10 31 c0 0f 01 ca c3 90 90 90 90 90 90 90 90 90 90 90 90 48 ba RSP: 0018:ffffc900099ffcd8 EFLAGS: 00050202 RAX: 0000000000000004 RBX: 0000000000000008 RCX: 0000000000000000 RDX: ffffffffffffffff RSI: 0000000000000000 RDI: ffffc900099ffe40 RBP: ffffc900099ffd30 R08: ffffc900099ffe3f R09: ffffc900099ffdc0 R10: dffffc0000000000 R11: fffff5200133ffc8 R12: 1ffff9200133ffb4 R13: 0000000000000004 R14: ffffc900099ffdc0 R15: 0000000000000000 __do_sys_perf_event_open kernel/events/core.c:12391 [inline] __se_sys_perf_event_open+0xf5/0x1bb0 kernel/events/core.c:12369 __x64_sys_perf_event_open+0xbf/0xd0 kernel/events/core.c:12369 x64_sys_call+0x385/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:299 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: 0033:0x7f4feb99cdd9 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:00007f4fec940028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007f4febc15fa0 RCX: 00007f4feb99cdd9 RDX: 0000000000000004 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f4feba32d69 R08: 0000000000000008 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4febc16038 R14: 00007f4febc15fa0 R15: 00007ffd7a1a80b8 Allocated by task 1144: 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: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 The buggy address belongs to the object at ffff888131c92680 which belongs to the cache kmalloc-64 of size 64 The buggy address is located 16 bytes inside of 64-byte region [ffff888131c92680, ffff888131c926c0) The buggy address belongs to the physical page: page:ffffea0004c72480 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x131c92 flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 ffffea00043fe500 dead000000000003 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 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 287, tgid 287 (syz-executor), ts 27461861888, free_ts 0 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2672 prep_new_page+0x1c/0x110 mm/page_alloc.c:2679 get_page_from_freelist+0x2d12/0x2d80 mm/page_alloc.c:4585 __alloc_pages+0x1fa/0x610 mm/page_alloc.c:5926 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+0xa1/0x1e0 mm/slab_common.c:951 kmalloc include/linux/slab.h:568 [inline] kzalloc include/linux/slab.h:699 [inline] tnode_alloc net/ipv4/fib_trie.c:332 [inline] tnode_new+0xc8/0x320 net/ipv4/fib_trie.c:385 inflate net/ipv4/fib_trie.c:596 [inline] resize+0x649/0x1c90 net/ipv4/fib_trie.c:869 trie_rebalance net/ipv4/fib_trie.c:1106 [inline] fib_insert_node net/ipv4/fib_trie.c:1150 [inline] fib_insert_alias+0xa1f/0x10b0 net/ipv4/fib_trie.c:1164 fib_table_insert+0x81d/0x1df0 net/ipv4/fib_trie.c:1359 fib_magic net/ipv4/fib_frontend.c:1118 [inline] fib_add_ifaddr+0x384/0xf10 net/ipv4/fib_frontend.c:1140 fib_inetaddr_event+0x15d/0x310 net/ipv4/fib_frontend.c:1454 page_owner free stack trace missing Memory state around the buggy address: ffff888131c92580: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888131c92600: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff888131c92680: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc ^ ffff888131c92700: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888131c92780: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess): 0: 01 ca add %ecx,%edx 2: c3 ret 3: 90 nop 4: 90 nop 5: 90 nop 6: 90 nop 7: 90 nop 8: 90 nop 9: 90 nop a: 90 nop b: 90 nop c: 90 nop d: 90 nop e: 48 ba fd ef ff ff ff movabs $0x7fffffffeffd,%rdx 15: 7f 00 00 18: 48 39 d0 cmp %rdx,%rax 1b: 0f 83 90 00 00 00 jae 0xb1 21: 48 19 d2 sbb %rdx,%rdx 24: 48 21 d0 and %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: 90 nop 3a: 90 nop 3b: 90 nop 3c: 90 nop 3d: 90 nop 3e: 48 rex.W 3f: ba .byte 0xba