================================================================== BUG: KASAN: slab-out-of-bounds in __bpf_get_stackid+0x6c9/0x920 kernel/bpf/stackmap.c:274 Write of size 56 at addr ffff88802992d110 by task syz.2.4840/22575 CPU: 1 PID: 22575 Comm: syz.2.4840 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0xa8/0x210 mm/kasan/report.c:420 kasan_report+0x10b/0x140 mm/kasan/report.c:524 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x235/0x290 mm/kasan/generic.c:189 memcpy+0x3c/0x60 mm/kasan/shadow.c:66 __bpf_get_stackid+0x6c9/0x920 kernel/bpf/stackmap.c:274 ____bpf_get_stackid_pe kernel/bpf/stackmap.c:365 [inline] bpf_get_stackid_pe+0x33f/0x400 kernel/bpf/stackmap.c:334 bpf_prog_ceda4e53fcf21ae1+0x28/0x40 bpf_dispatcher_nop_func include/linux/bpf.h:1012 [inline] __bpf_prog_run include/linux/filter.h:596 [inline] bpf_prog_run include/linux/filter.h:614 [inline] bpf_overflow_handler+0x6e8/0x7c0 kernel/events/core.c:10286 __perf_event_overflow+0x448/0x610 kernel/events/core.c:9496 do_perf_sw_event kernel/events/core.c:9713 [inline] ___perf_sw_event+0x49e/0x6e0 kernel/events/core.c:9744 __perf_sw_event+0x135/0x260 kernel/events/core.c:9756 perf_sw_event include/linux/perf_event.h:1254 [inline] do_user_addr_fault+0xaea/0xb10 arch/x86/mm/fault.c:1284 handle_page_fault arch/x86/mm/fault.c:1429 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1482 asm_exc_page_fault+0x22/0x30 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+0x14b/0x350 lib/strncpy_from_user.c:139 Code: 4c 89 e6 e8 d7 3e 4a fd 49 83 fc 07 0f 86 a1 00 00 00 4c 89 74 24 08 48 c7 44 24 10 f8 ff ff ff 45 31 ed 4c 89 3c 24 48 89 dd <4f> 8b 3c 2f 48 b8 ff fe fe fe fe fe fe fe 49 8d 1c 07 4d 89 fe 49 RSP: 0018:ffffc9000e0a7b50 EFLAGS: 00050246 RAX: ffffffff843838b9 RBX: ffffc9000e0a7c70 RCX: ffff88802dff3b80 RDX: 0000000000000002 RSI: 000000000000007f RDI: 0000000000000007 RBP: ffffc9000e0a7c70 R08: ffff88802dff3b80 R09: 0000000000000003 R10: 0000000000000002 R11: 0000000000000002 R12: 000000000000007f R13: 0000000000000000 R14: 000000000000007f R15: 0000000000000000 strncpy_from_bpfptr include/linux/bpfptr.h:85 [inline] bpf_prog_load+0x1f3/0x1560 kernel/bpf/syscall.c:2535 __sys_bpf+0x5b8/0x780 kernel/bpf/syscall.c:5030 __do_sys_bpf kernel/bpf/syscall.c:5134 [inline] __se_sys_bpf kernel/bpf/syscall.c:5132 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5132 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: 0033:0x7f29f719bf79 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:00007f29f80a7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f29f7415fa0 RCX: 00007f29f719bf79 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 00007f29f72327e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f29f7416038 R14: 00007f29f7415fa0 R15: 00007ffedaf9d758 Allocated by task 22575: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:384 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slab_common.c:936 [inline] __kmalloc_node+0xb0/0x240 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+0x47/0xe0 kernel/bpf/syscall.c:341 prealloc_elems_and_freelist+0x86/0x1c0 kernel/bpf/stackmap.c:51 stack_map_alloc+0x390/0x520 kernel/bpf/stackmap.c:117 find_and_alloc_map kernel/bpf/syscall.c:133 [inline] map_create+0x534/0x1000 kernel/bpf/syscall.c:1149 __sys_bpf+0x38b/0x780 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+0x78/0x90 kernel/bpf/syscall.c:5132 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 ffff88802992d100 which belongs to the cache kmalloc-cg-64 of size 64 The buggy address is located 16 bytes inside of 64-byte region [ffff88802992d100, ffff88802992d140) The buggy address belongs to the physical page: page:ffffea0000a64b40 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2992d memcg:ffff88807b18e801 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 0000000000000000 dead000000000001 ffff888017442780 raw: 0000000000000000 0000000080200020 00000001ffffffff ffff88807b18e801 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 11897, tgid 11897 (syz-executor), ts 934267370917, free_ts 934266925849 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2559 prep_new_page mm/page_alloc.c:2566 [inline] get_page_from_freelist+0x1a1e/0x1ab0 mm/page_alloc.c:4357 __alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5643 alloc_slab_page+0x5d/0x160 mm/slub.c:1799 allocate_slab mm/slub.c:1944 [inline] new_slab+0x87/0x2c0 mm/slub.c:1997 ___slab_alloc+0xbc6/0x1240 mm/slub.c:3154 __slab_alloc mm/slub.c:3240 [inline] slab_alloc_node mm/slub.c:3325 [inline] __kmem_cache_alloc_node+0x1a0/0x260 mm/slub.c:3398 kmalloc_trace+0x26/0xe0 mm/slab_common.c:1026 kmalloc include/linux/slab.h:563 [inline] alloc_fdtable+0xca/0x2c0 fs/file.c:147 dup_fd+0x782/0xa50 fs/file.c:346 copy_files+0x72/0xe0 kernel/fork.c:1641 copy_process+0x1835/0x4030 kernel/fork.c:2344 kernel_clone+0x24b/0x900 kernel/fork.c:2762 __do_sys_clone kernel/fork.c:2903 [inline] __se_sys_clone kernel/fork.c:2887 [inline] __x64_sys_clone+0x1a7/0x220 kernel/fork.c:2887 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 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1486 [inline] free_pcp_prepare mm/page_alloc.c:1536 [inline] free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3413 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3508 __vunmap+0x856/0xa00 mm/vmalloc.c:2726 copy_entries_to_user net/ipv6/netfilter/ip6_tables.c:884 [inline] get_entries net/ipv6/netfilter/ip6_tables.c:1041 [inline] do_ip6t_get_ctl+0xec0/0x11b0 net/ipv6/netfilter/ip6_tables.c:1679 nf_getsockopt+0x25e/0x280 net/netfilter/nf_sockopt.c:116 ipv6_getsockopt+0x222/0x2e0 net/ipv6/ipv6_sockglue.c:1512 __sys_getsockopt+0x1b0/0x230 net/socket.c:2331 __do_sys_getsockopt net/socket.c:2346 [inline] __se_sys_getsockopt net/socket.c:2343 [inline] __x64_sys_getsockopt+0xb1/0xc0 net/socket.c:2343 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: ffff88802992d000: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff88802992d080: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc >ffff88802992d100: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc ^ ffff88802992d180: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff88802992d200: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess): 0: 4c 89 e6 mov %r12,%rsi 3: e8 d7 3e 4a fd call 0xfd4a3edf 8: 49 83 fc 07 cmp $0x7,%r12 c: 0f 86 a1 00 00 00 jbe 0xb3 12: 4c 89 74 24 08 mov %r14,0x8(%rsp) 17: 48 c7 44 24 10 f8 ff movq $0xfffffffffffffff8,0x10(%rsp) 1e: ff ff 20: 45 31 ed xor %r13d,%r13d 23: 4c 89 3c 24 mov %r15,(%rsp) 27: 48 89 dd mov %rbx,%rbp * 2a: 4f 8b 3c 2f mov (%r15,%r13,1),%r15 <-- trapping instruction 2e: 48 b8 ff fe fe fe fe movabs $0xfefefefefefefeff,%rax 35: fe fe fe 38: 49 8d 1c 07 lea (%r15,%rax,1),%rbx 3c: 4d 89 fe mov %r15,%r14 3f: 49 rex.WB