================================================================== BUG: KASAN: slab-out-of-bounds in __bpf_get_stackid+0x6bf/0x900 kernel/bpf/stackmap.c:271 Write of size 72 at addr ffff88805e53b210 by task syz.1.2919/16226 CPU: 1 PID: 16226 Comm: syz.1.2919 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 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_02c92f715e75ceb8+0x30/0x45 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:10584 __perf_event_overflow+0x447/0x630 kernel/events/core.c:9720 perf_swevent_overflow+0x268/0x340 kernel/events/core.c:9803 perf_swevent_event+0x45c/0x570 kernel/events/core.c:-1 do_perf_sw_event kernel/events/core.c:9967 [inline] ___perf_sw_event+0x4a7/0x730 kernel/events/core.c:9998 __perf_sw_event+0x139/0x270 kernel/events/core.c:10010 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:rep_movs_alternative+0x33/0x90 arch/x86/lib/copy_user_64.S:58 Code: 40 83 f9 08 73 21 85 c9 74 0f 8a 06 88 07 48 ff c7 48 ff c6 48 ff c9 75 f1 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 48 8b 06 <48> 89 07 48 83 c6 08 48 83 c7 08 83 e9 08 74 df 83 f9 08 73 e8 eb RSP: 0018:ffffc9000c83edd0 EFLAGS: 00050202 RAX: 2064696c61766e69 RBX: 000000000000002b RCX: 000000000000002b RDX: 0000000000000000 RSI: ffff88802dcf068c RDI: 000000000000cf3d RBP: ffff88802dcf0688 R08: ffff88802dcf06b6 R09: 1ffff11005b9e0d6 R10: dffffc0000000000 R11: ffffed1005b9e0d7 R12: 000000000000cf68 R13: ffff88802dcf068c R14: 000000000000cf3d R15: ffff88802dcf068c copy_user_generic arch/x86/include/asm/uaccess_64.h:112 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:133 [inline] _copy_to_user+0x85/0xa0 lib/usercopy.c:41 copy_to_user include/linux/uaccess.h:191 [inline] bpf_verifier_vlog+0x45c/0x870 kernel/bpf/log.c:87 verbose+0x11e/0x1a0 kernel/bpf/verifier.c:370 check_ctx_access+0x251/0x440 kernel/bpf/verifier.c:5606 check_mem_access+0xa18/0x19f0 kernel/bpf/verifier.c:6828 do_check+0x5de9/0xdbf0 kernel/bpf/verifier.c:17216 do_check_common+0xadb/0x13e0 kernel/bpf/verifier.c:19706 do_check_main kernel/bpf/verifier.c:19769 [inline] bpf_check+0x658e/0xeba0 kernel/bpf/verifier.c:20437 bpf_prog_load+0x1163/0x1670 kernel/bpf/syscall.c:2753 __sys_bpf+0x5ba/0x890 kernel/bpf/syscall.c:5477 __do_sys_bpf kernel/bpf/syscall.c:5581 [inline] __se_sys_bpf kernel/bpf/syscall.c:5579 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5579 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: 0033:0x7f55fe59c819 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:00007f55ff47f028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f55fe815fa0 RCX: 00007f55fe59c819 RDX: 0000000000000023 RSI: 000020000000e000 RDI: 0000000000000005 RBP: 00007f55fe632c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f55fe816038 R14: 00007f55fe815fa0 R15: 00007ffc86669f48 Allocated by task 16226: 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:5459 __do_sys_bpf kernel/bpf/syscall.c:5581 [inline] __se_sys_bpf kernel/bpf/syscall.c:5579 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5579 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 ffff88805e53b200 which belongs to the cache kmalloc-cg-64 of size 64 The buggy address is located 16 bytes inside of allocated 40-byte region [ffff88805e53b200, ffff88805e53b228) The buggy address belongs to the physical page: page:ffffea0001794ec0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5e53b memcg:ffff88807de7f601 flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000800 ffff888017c4da00 ffffea0001784ac0 0000000000000002 raw: 0000000000000000 0000000080200020 00000001ffffffff ffff88807de7f601 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112800(GFP_NOWAIT|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 15815, tgid 15814 (syz.3.2803), ts 494628769044, free_ts 494623295991 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 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc_node+0xa4/0x230 mm/slab_common.c:1014 kmalloc_node include/linux/slab.h:620 [inline] bpf_map_kmalloc_node+0xbc/0x1b0 kernel/bpf/syscall.c:424 lpm_trie_node_alloc kernel/bpf/lpm_trie.c:291 [inline] trie_update_elem+0x169/0xea0 kernel/bpf/lpm_trie.c:338 bpf_map_update_value+0x660/0x720 kernel/bpf/syscall.c:203 generic_map_update_batch+0x5ec/0x810 kernel/bpf/syscall.c:1800 bpf_map_do_batch+0x3d7/0x610 kernel/bpf/syscall.c:5010 __sys_bpf+0x381/0x890 kernel/bpf/syscall.c:-1 __do_sys_bpf kernel/bpf/syscall.c:5581 [inline] __se_sys_bpf kernel/bpf/syscall.c:5579 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5579 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 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 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: ffff88805e53b100: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff88805e53b180: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc >ffff88805e53b200: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc ^ ffff88805e53b280: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff88805e53b300: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess): 0: 40 83 f9 08 rex cmp $0x8,%ecx 4: 73 21 jae 0x27 6: 85 c9 test %ecx,%ecx 8: 74 0f je 0x19 a: 8a 06 mov (%rsi),%al c: 88 07 mov %al,(%rdi) e: 48 ff c7 inc %rdi 11: 48 ff c6 inc %rsi 14: 48 ff c9 dec %rcx 17: 75 f1 jne 0xa 19: c3 ret 1a: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1) 21: 00 00 00 24: 0f 1f 00 nopl (%rax) 27: 48 8b 06 mov (%rsi),%rax * 2a: 48 89 07 mov %rax,(%rdi) <-- trapping instruction 2d: 48 83 c6 08 add $0x8,%rsi 31: 48 83 c7 08 add $0x8,%rdi 35: 83 e9 08 sub $0x8,%ecx 38: 74 df je 0x19 3a: 83 f9 08 cmp $0x8,%ecx 3d: 73 e8 jae 0x27 3f: eb .byte 0xeb