================================================================== BUG: KASAN: slab-out-of-bounds in __bpf_get_stackid+0x6c9/0x920 kernel/bpf/stackmap.c:274 Write of size 88 at addr ffff888028923090 by task syz.0.252/5410 CPU: 1 PID: 5410 Comm: syz.0.252 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 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_ee9fdca00c0e1e15+0x28/0x3d bpf_dispatcher_nop_func include/linux/bpf.h:1012 [inline] __bpf_prog_run include/linux/filter.h:608 [inline] bpf_prog_run include/linux/filter.h:615 [inline] bpf_overflow_handler+0x50b/0x790 kernel/events/core.c:10331 __perf_event_overflow+0x457/0x630 kernel/events/core.c:9506 perf_swevent_overflow kernel/events/core.c:9589 [inline] perf_swevent_event+0x315/0x570 kernel/events/core.c:9640 do_perf_sw_event kernel/events/core.c:9753 [inline] ___perf_sw_event+0x498/0x6d0 kernel/events/core.c:9784 __perf_sw_event+0x135/0x260 kernel/events/core.c:9796 perf_sw_event include/linux/perf_event.h:1254 [inline] do_user_addr_fault+0x497/0xb20 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:copy_user_enhanced_fast_string+0xa/0x40 arch/x86/lib/copy_user_64.S:166 Code: ff c9 75 f2 89 d1 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 31 c0 0f 01 ca c3 8d 0c ca 89 ca eb 20 0f 01 cb 83 fa 40 72 38 89 d1 a4 31 c0 0f 01 ca c3 89 ca eb 0a 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc9000674f608 EFLAGS: 00050206 RAX: ffffffff84143201 RBX: 0000000000008000 RCX: 0000000000006440 RDX: 0000000000008000 RSI: 0000200000002000 RDI: ffff88807e1a1bc0 RBP: 0000000000000000 R08: ffff88807e1a7fff R09: 1ffff1100fc34fff R10: dffffc0000000000 R11: ffffed100fc35000 R12: 00007fffffff7000 R13: 0000000000000000 R14: 0000200000000440 R15: ffff88807e1a0000 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline] raw_copy_from_user arch/x86/include/asm/uaccess_64.h:52 [inline] copyin+0xe7/0x120 lib/iov_iter.c:183 _copy_from_iter+0x447/0x1130 lib/iov_iter.c:632 copy_from_iter include/linux/uio.h:187 [inline] copy_from_iter_full include/linux/uio.h:194 [inline] skb_do_copy_data_nocache include/net/sock.h:2369 [inline] skb_copy_to_page_nocache include/net/sock.h:2395 [inline] tcp_sendmsg_locked+0x17ec/0x39e0 net/ipv4/tcp.c:1387 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1494 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:730 [inline] ____sys_sendmsg+0x5ed/0x9a0 net/socket.c:2519 ___sys_sendmsg+0x2a2/0x360 net/socket.c:2573 __sys_sendmsg net/socket.c:2602 [inline] __do_sys_sendmsg net/socket.c:2611 [inline] __se_sys_sendmsg+0x1c3/0x2b0 net/socket.c:2609 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: 0033:0x7f747bf9e159 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:00007f747cf0a028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f747c226090 RCX: 00007f747bf9e159 RDX: 0000000000040001 RSI: 00002000000008c0 RDI: 000000000000000f RBP: 00007f747c03506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f747c226128 R14: 00007f747c226090 R15: 00007ffd19d47968 Allocated by task 5410: 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+0xb2/0x240 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+0x386/0x510 kernel/bpf/stackmap.c:117 find_and_alloc_map kernel/bpf/syscall.c:133 [inline] map_create+0x524/0xff0 kernel/bpf/syscall.c:1149 __sys_bpf+0x38b/0x780 kernel/bpf/syscall.c:5014 __do_sys_bpf kernel/bpf/syscall.c:5136 [inline] __se_sys_bpf kernel/bpf/syscall.c:5134 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5134 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 ffff888028923080 which belongs to the cache kmalloc-cg-64 of size 64 The buggy address is located 16 bytes inside of 64-byte region [ffff888028923080, ffff8880289230c0) The buggy address belongs to the physical page: page:ffffea0000a248c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888028923f00 pfn:0x28923 memcg:ffff88807de4da01 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea0000a87880 dead000000000002 ffff888017442780 raw: ffff888028923f00 000000008020001f 00000001ffffffff ffff88807de4da01 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 4422, tgid 4415 (syz.4.5), ts 341734835129, free_ts 341701281865 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2560 prep_new_page mm/page_alloc.c:2567 [inline] get_page_from_freelist+0x206b/0x2180 mm/page_alloc.c:4358 __alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5658 alloc_slab_page+0x5d/0x180 mm/slub.c:1799 allocate_slab mm/slub.c:1944 [inline] new_slab+0x87/0x2d0 mm/slub.c:1997 ___slab_alloc+0xbc5/0x1240 mm/slub.c:3154 __slab_alloc mm/slub.c:3240 [inline] slab_alloc_node mm/slub.c:3325 [inline] __kmem_cache_alloc_node+0x126/0x270 mm/slub.c:3398 kmalloc_trace+0x26/0xe0 mm/slab_common.c:1026 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] alloc_cgroup_ns kernel/cgroup/namespace.c:27 [inline] copy_cgroup_ns+0x2c2/0x610 kernel/cgroup/namespace.c:79 create_new_namespaces+0x335/0x700 kernel/nsproxy.c:103 copy_namespaces+0x3ae/0x410 kernel/nsproxy.c:178 copy_process+0x199b/0x4070 kernel/fork.c:2361 kernel_clone+0x24b/0x900 kernel/fork.c:2765 __do_sys_clone kernel/fork.c:2906 [inline] __se_sys_clone kernel/fork.c:2890 [inline] __x64_sys_clone+0x1a7/0x220 kernel/fork.c:2890 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:1487 [inline] free_pcp_prepare mm/page_alloc.c:1537 [inline] free_unref_page_prepare+0x8e5/0x9e0 mm/page_alloc.c:3414 free_unref_page_list+0xbb/0x8e0 mm/page_alloc.c:3555 release_pages+0x20d1/0x2340 mm/swap.c:1035 tlb_batch_pages_flush mm/mmu_gather.c:60 [inline] tlb_flush_mmu_free mm/mmu_gather.c:255 [inline] tlb_flush_mmu+0x105/0x220 mm/mmu_gather.c:262 tlb_finish_mmu+0xf0/0x220 mm/mmu_gather.c:394 exit_mmap+0x388/0x970 mm/mmap.c:3262 __mmput+0x118/0x3a0 kernel/fork.c:1210 exit_mm+0x24d/0x350 kernel/exit.c:572 do_exit+0x958/0x2570 kernel/exit.c:874 do_group_exit+0x229/0x2e0 kernel/exit.c:1030 get_signal+0x1259/0x1340 kernel/signal.c:2884 arch_do_signal_or_restart+0xc4/0x1310 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:213 __syscall_exit_to_user_mode_work kernel/entry/common.c:295 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:306 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82 Memory state around the buggy address: ffff888028922f80: 00 04 fc fc 00 04 fc fc 00 07 fc fc 00 05 fc fc ffff888028923000: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff888028923080: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc ^ ffff888028923100: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc ffff888028923180: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess): 0: ff c9 dec %ecx 2: 75 f2 jne 0xfffffff6 4: 89 d1 mov %edx,%ecx 6: c1 e9 03 shr $0x3,%ecx 9: 83 e2 07 and $0x7,%edx c: f3 48 a5 rep movsq %ds:(%rsi),%es:(%rdi) f: 89 d1 mov %edx,%ecx 11: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) 13: 31 c0 xor %eax,%eax 15: 0f 01 ca clac 18: c3 ret 19: 8d 0c ca lea (%rdx,%rcx,8),%ecx 1c: 89 ca mov %ecx,%edx 1e: eb 20 jmp 0x40 20: 0f 01 cb stac 23: 83 fa 40 cmp $0x40,%edx 26: 72 38 jb 0x60 28: 89 d1 mov %edx,%ecx * 2a: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) <-- trapping instruction 2c: 31 c0 xor %eax,%eax 2e: 0f 01 ca clac 31: c3 ret 32: 89 ca mov %ecx,%edx 34: eb 0a jmp 0x40 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: 90 nop 3f: 90 nop