================================================================== BUG: KASAN: slab-out-of-bounds in __bpf_get_stackid+0x6fa/0x960 kernel/bpf/stackmap.c:274 Write of size 72 at addr ffff88811d882b90 by task syz.4.423/1770 CPU: 1 PID: 1770 Comm: syz.4.423 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 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_02c92f715e75ceb8+0x28/0x3d bpf_dispatcher_nop_func include/linux/bpf.h:987 [inline] __bpf_prog_run include/linux/filter.h:596 [inline] bpf_prog_run include/linux/filter.h:614 [inline] bpf_overflow_handler+0x51f/0x5e0 kernel/events/core.c:10238 __perf_event_overflow+0x437/0x620 kernel/events/core.c:9448 perf_swevent_overflow kernel/events/core.c:9524 [inline] perf_swevent_event+0x2f7/0x530 kernel/events/core.c:-1 do_perf_sw_event kernel/events/core.c:9665 [inline] ___perf_sw_event+0x3bf/0x4f0 kernel/events/core.c:9696 __perf_sw_event+0x134/0x270 kernel/events/core.c:9708 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:do_strncpy_from_user lib/strncpy_from_user.c:41 [inline] RIP: 0010:strncpy_from_user+0xdf/0x2d0 lib/strncpy_from_user.c:139 Code: 00 00 4c 89 ee e8 11 17 e2 fe 49 83 fd 07 0f 86 a2 00 00 00 4c 89 75 c0 49 c7 c7 f8 ff ff ff 45 31 e4 4c 89 65 c8 48 8b 45 c0 <4a> 8b 1c 20 48 b8 ff fe fe fe fe fe fe fe 4c 8d 34 03 49 89 dc 49 RSP: 0018:ffffc9000dd77cb8 EFLAGS: 00050246 RAX: 0000000000000000 RBX: 0000000000000fe0 RCX: ffff88811a8a6540 RDX: 0000000000000002 RSI: 0000000000000fe0 RDI: 0000000000000007 RBP: ffffc9000dd77d00 R08: ffffea00045b6a07 R09: 1ffffd40008b6d40 R10: dffffc0000000000 R11: fffff940008b6d41 R12: 0000000000000000 R13: 0000000000000fe0 R14: 0000000000000000 R15: fffffffffffffff8 getname_flags+0xf4/0x500 fs/namei.c:150 getname+0x19/0x20 fs/namei.c:218 do_sys_openat2+0xeb/0x810 fs/open.c:1337 do_sys_open fs/open.c:1359 [inline] __do_sys_openat fs/open.c:1375 [inline] __se_sys_openat fs/open.c:1370 [inline] __x64_sys_openat+0x136/0x160 fs/open.c:1370 x64_sys_call+0x783/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:258 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: 0033:0x7fe6b9f9c819 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:00007fe6b89f7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fe6ba215fa0 RCX: 00007fe6b9f9c819 RDX: 0000000000200002 RSI: 0000000000000000 RDI: ffffffffffffff9c RBP: 00007fe6ba032c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fe6ba216038 R14: 00007fe6ba215fa0 R15: 00007ffef6cf06f8 Allocated by task 1770: 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:4987 __do_sys_bpf kernel/bpf/syscall.c:5109 [inline] __se_sys_bpf kernel/bpf/syscall.c:5107 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5107 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 ffff88811d882b80 which belongs to the cache kmalloc-64 of size 64 The buggy address is located 16 bytes inside of 64-byte region [ffff88811d882b80, ffff88811d882bc0) The buggy address belongs to the physical page: page:ffffea0004762080 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11d882 flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 0000000000000000 dead000000000001 ffff888100042780 raw: 0000000000000000 0000000000200020 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 134, tgid 134 (ip), ts 7522043917, free_ts 0 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2670 prep_new_page+0x1c/0x110 mm/page_alloc.c:2677 get_page_from_freelist+0x2d12/0x2d80 mm/page_alloc.c:4583 __alloc_pages+0x1fa/0x610 mm/page_alloc.c:5924 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] fib_trie_table+0x33/0x190 net/ipv4/fib_trie.c:2395 fib_new_table+0x138/0x2b0 net/ipv4/fib_frontend.c:90 fib_new_table+0x12d/0x2b0 net/ipv4/fib_frontend.c:88 fib_magic net/ipv4/fib_frontend.c:1106 [inline] fib_add_ifaddr+0x326/0xf10 net/ipv4/fib_frontend.c:1140 fib_inetaddr_event+0x15d/0x310 net/ipv4/fib_frontend.c:1454 notifier_call_chain kernel/notifier.c:87 [inline] blocking_notifier_call_chain+0xcb/0x150 kernel/notifier.c:382 page_owner free stack trace missing Memory state around the buggy address: ffff88811d882a80: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff88811d882b00: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc >ffff88811d882b80: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc ^ ffff88811d882c00: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff88811d882c80: 00 00 00 00 00 00 00 03 fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 4c 89 ee mov %r13,%rsi 5: e8 11 17 e2 fe call 0xfee2171b a: 49 83 fd 07 cmp $0x7,%r13 e: 0f 86 a2 00 00 00 jbe 0xb6 14: 4c 89 75 c0 mov %r14,-0x40(%rbp) 18: 49 c7 c7 f8 ff ff ff mov $0xfffffffffffffff8,%r15 1f: 45 31 e4 xor %r12d,%r12d 22: 4c 89 65 c8 mov %r12,-0x38(%rbp) 26: 48 8b 45 c0 mov -0x40(%rbp),%rax * 2a: 4a 8b 1c 20 mov (%rax,%r12,1),%rbx <-- trapping instruction 2e: 48 b8 ff fe fe fe fe movabs $0xfefefefefefefeff,%rax 35: fe fe fe 38: 4c 8d 34 03 lea (%rbx,%rax,1),%r14 3c: 49 89 dc mov %rbx,%r12 3f: 49 rex.WB