================================================================== BUG: KASAN: slab-out-of-bounds in __bpf_get_stackid+0x6fa/0x960 kernel/bpf/stackmap.c:274 Write of size 72 at addr ffff88810c95f890 by task syz.2.17/566 CPU: 0 PID: 566 Comm: syz.2.17 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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_47e2b75ffb32ae9a+0x21/0x39 bpf_dispatcher_nop_func include/linux/bpf.h:1012 [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:10286 __perf_event_overflow+0x437/0x620 kernel/events/core.c:9496 perf_swevent_overflow kernel/events/core.c:9572 [inline] perf_swevent_event+0x2f7/0x530 kernel/events/core.c:-1 do_perf_sw_event kernel/events/core.c:9713 [inline] ___perf_sw_event+0x3bf/0x4f0 kernel/events/core.c:9744 __perf_sw_event+0x134/0x270 kernel/events/core.c:9756 perf_sw_event include/linux/perf_event.h:1254 [inline] do_user_addr_fault+0xacb/0xaf0 arch/x86/mm/fault.c:1286 handle_page_fault arch/x86/mm/fault.c:1431 [inline] exc_page_fault+0x51/0xb0 arch/x86/mm/fault.c:1487 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 f1 c3 ec 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:ffffc90000b8fcf8 EFLAGS: 00050246 RAX: 0000000000000000 RBX: 0000000000000fe0 RCX: ffff888117336480 RDX: 0000000000000000 RSI: 0000000000000fe0 RDI: 0000000000000007 RBP: ffffc90000b8fd40 R08: ffffea0004327c07 R09: 1ffffd4000864f80 R10: dffffc0000000000 R11: fffff94000864f81 R12: 0000000000000000 R13: 0000000000000fe0 R14: 0000000000000000 R15: fffffffffffffff8 getname_flags+0xf5/0x510 fs/namei.c:150 getname+0x19/0x20 fs/namei.c:218 do_sys_openat2+0xdd/0x4b0 fs/open.c:1314 do_sys_open fs/open.c:1336 [inline] __do_sys_openat fs/open.c:1352 [inline] __se_sys_openat fs/open.c:1347 [inline] __x64_sys_openat+0x136/0x160 fs/open.c:1347 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: 0033:0x7f602359aeb9 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:00007f60243e8028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f6023815fa0 RCX: 00007f602359aeb9 RDX: 00000000000026e1 RSI: 0000000000000000 RDI: ffffffffffffff9c RBP: 00007f6023608c1f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6023816038 R14: 00007f6023815fa0 R15: 00007ffc46abbf08 Allocated by task 567: 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:375 [inline] __kasan_kmalloc+0x95/0xb0 mm/kasan/common.c:384 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slab_common.c:936 [inline] __kmalloc_node+0xb2/0x1e0 mm/slab_common.c:943 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/0xf50 kernel/bpf/syscall.c:1149 __sys_bpf+0x345/0x750 kernel/bpf/syscall.c:5012 __do_sys_bpf kernel/bpf/syscall.c:5134 [inline] __se_sys_bpf kernel/bpf/syscall.c:5132 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5132 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 ffff88810c95f880 which belongs to the cache kmalloc-64 of size 64 The buggy address is located 16 bytes inside of 64-byte region [ffff88810c95f880, ffff88810c95f8c0) The buggy address belongs to the physical page: page:ffffea00043257c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10c95f flags: 0x4000000000000200(slab|zone=1) raw: 4000000000000200 0000000000000000 dead000000000122 ffff888100041640 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 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 554, tgid 554 (syz-executor), ts 47874144245, free_ts 47873935644 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1d0/0x1f0 mm/page_alloc.c:2532 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x2e56/0x2ee0 mm/page_alloc.c:4328 __alloc_pages+0x242/0x4c0 mm/page_alloc.c:5614 alloc_slab_page include/linux/gfp.h:-1 [inline] allocate_slab mm/slub.c:1944 [inline] new_slab+0xec/0x4b0 mm/slub.c:1997 ___slab_alloc+0x6bd/0xb20 mm/slub.c:3154 __slab_alloc+0x5e/0xa0 mm/slub.c:3240 slab_alloc_node mm/slub.c:3325 [inline] __kmem_cache_alloc_node+0x1b1/0x260 mm/slub.c:3398 kmalloc_node_trace+0x26/0xb0 mm/slab_common.c:1039 kmalloc_node include/linux/slab.h:585 [inline] kzalloc_node include/linux/slab.h:710 [inline] __get_vm_area_node+0x12c/0x360 mm/vmalloc.c:2506 __vmalloc_node_range+0x326/0x1430 mm/vmalloc.c:3203 __vmalloc_node mm/vmalloc.c:3308 [inline] vzalloc+0x78/0x90 mm/vmalloc.c:3381 alloc_counters+0x66/0x530 net/ipv4/netfilter/ip_tables.c:801 copy_entries_to_user net/ipv4/netfilter/ip_tables.c:823 [inline] get_entries net/ipv4/netfilter/ip_tables.c:1024 [inline] do_ipt_get_ctl+0xa6d/0x1180 net/ipv4/netfilter/ip_tables.c:1670 nf_getsockopt+0x27f/0x2a0 net/netfilter/nf_sockopt.c:116 ip_getsockopt+0x157/0x1e0 net/ipv4/ip_sockglue.c:1826 tcp_getsockopt+0xff/0x130 net/ipv4/tcp.c:4475 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1459 [inline] free_pcp_prepare mm/page_alloc.c:1532 [inline] free_unref_page_prepare+0x742/0x750 mm/page_alloc.c:3384 free_unref_page+0x33/0x390 mm/page_alloc.c:3479 free_the_page mm/page_alloc.c:754 [inline] __free_pages+0x67/0x100 mm/page_alloc.c:5703 __vunmap+0x9c0/0xb80 mm/vmalloc.c:2726 __vfree mm/vmalloc.c:2775 [inline] vfree+0x61/0x90 mm/vmalloc.c:2806 copy_entries_to_user net/ipv4/netfilter/ip_tables.c:868 [inline] get_entries net/ipv4/netfilter/ip_tables.c:1024 [inline] do_ipt_get_ctl+0xe9c/0x1180 net/ipv4/netfilter/ip_tables.c:1670 nf_getsockopt+0x27f/0x2a0 net/netfilter/nf_sockopt.c:116 ip_getsockopt+0x157/0x1e0 net/ipv4/ip_sockglue.c:1826 tcp_getsockopt+0xff/0x130 net/ipv4/tcp.c:4475 sock_common_getsockopt+0xaa/0xc0 net/core/sock.c:3663 __sys_getsockopt+0x215/0x4a0 net/socket.c:2332 __do_sys_getsockopt net/socket.c:2347 [inline] __se_sys_getsockopt net/socket.c:2344 [inline] __x64_sys_getsockopt+0xbf/0xd0 net/socket.c:2344 x64_sys_call+0x3d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:56 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 Memory state around the buggy address: ffff88810c95f780: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff88810c95f800: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff88810c95f880: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc ^ ffff88810c95f900: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff88810c95f980: fc fc fc fc fc fc fc fc 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 f1 c3 ec fe call 0xfeecc3fb 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