================================================================== BUG: KASAN: slab-out-of-bounds in stack_map_get_build_id_offset+0x6c0/0x720 kernel/bpf/stackmap.c:144 Write of size 4 at addr ffff88802c7d3330 by task syz.0.18/5934 CPU: 1 PID: 5934 Comm: syz.0.18 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 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 stack_map_get_build_id_offset+0x6c0/0x720 kernel/bpf/stackmap.c:144 __bpf_get_stackid+0x564/0x900 kernel/bpf/stackmap.c:247 ____bpf_get_stackid_pe kernel/bpf/stackmap.c:362 [inline] bpf_get_stackid_pe+0x343/0x410 kernel/bpf/stackmap.c:331 bpf_prog_2414a5d5030ea31b+0x29/0x2d bpf_dispatcher_nop_func include/linux/bpf.h:1224 [inline] __bpf_prog_run include/linux/filter.h:617 [inline] bpf_prog_run include/linux/filter.h:624 [inline] bpf_overflow_handler+0x1fc/0x510 kernel/events/core.c:10584 __perf_event_overflow+0x461/0x660 kernel/events/core.c:9720 perf_swevent_overflow kernel/events/core.c:9803 [inline] perf_swevent_event+0x319/0x570 kernel/events/core.c:9854 do_perf_sw_event kernel/events/core.c:9967 [inline] ___perf_sw_event+0x4ab/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+0x1242/0x12d0 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+0x15/0x90 arch/x86/lib/copy_user_64.S:44 Code: 8b 1c 24 4c 8b 64 24 08 48 83 c4 10 c3 cc cc cc cc cc cc cc cc f3 0f 1e fa 48 83 f9 40 73 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 RSP: 0018:ffffc900031c6f50 EFLAGS: 00050206 RAX: ffffffff8433ce30 RBX: 0000000000000003 RCX: 0000000000000003 RDX: 0000000000000000 RSI: ffff88801ffb068c RDI: 000020000000cf3d RBP: ffff88801ffb0668 R08: ffff88801ffb068e R09: 1ffff11003ff60d1 R10: dffffc0000000000 R11: ffffed1003ff60d2 R12: 000020000000cf40 R13: 0000000000000003 R14: 000020000000cf3d R15: ffff88801ffb068c 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+0x2f1/0x840 kernel/bpf/log.c:124 verbose+0x11e/0x1a0 kernel/bpf/verifier.c:370 print_insn_state+0x130/0x160 kernel/bpf/verifier.c:1566 do_check+0x4f08/0xd0a0 kernel/bpf/verifier.c:17330 do_check_common+0xacc/0x1410 kernel/bpf/verifier.c:19903 do_check_main kernel/bpf/verifier.c:19966 [inline] bpf_check+0x65d1/0xec30 kernel/bpf/verifier.c:20634 bpf_prog_load+0x10fa/0x1610 kernel/bpf/syscall.c:2753 __sys_bpf+0x5ba/0x890 kernel/bpf/syscall.c:5478 __do_sys_bpf kernel/bpf/syscall.c:5582 [inline] __se_sys_bpf kernel/bpf/syscall.c:5580 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5580 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f9f3a79e159 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:00007ffedf80c0a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f9f3aa25fa0 RCX: 00007f9f3a79e159 RDX: 0000000000000048 RSI: 0000200000000080 RDI: 0000000000000005 RBP: 00007f9f3a835024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9f3aa25fac R14: 00007f9f3aa25fa0 R15: 00007f9f3aa25fa0 Allocated by task 5934: 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+0xb6/0x240 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+0x32b/0x4b0 kernel/bpf/stackmap.c:114 map_create+0x877/0x12f0 kernel/bpf/syscall.c:1247 __sys_bpf+0x651/0x890 kernel/bpf/syscall.c:5460 __do_sys_bpf kernel/bpf/syscall.c:5582 [inline] __se_sys_bpf kernel/bpf/syscall.c:5580 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5580 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff88802c7d3000 which belongs to the cache kmalloc-cg-1k of size 1024 The buggy address is located 0 bytes to the right of allocated 816-byte region [ffff88802c7d3000, ffff88802c7d3330) The buggy address belongs to the physical page: page:ffffea0000b1f400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2c7d0 head:ffffea0000b1f400 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff88801a75c901 ksm flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888017c4f280 ffffea0001da5200 0000000000000003 raw: 0000000000000000 0000000080100010 00000001ffffffff ffff88801a75c901 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5433, tgid 5433 (dhcpcd), ts 70188463112, free_ts 70187373247 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1582 prep_new_page mm/page_alloc.c:1589 [inline] get_page_from_freelist+0x2181/0x22a0 mm/page_alloc.c:3221 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4501 alloc_slab_page+0x5d/0x180 mm/slub.c:1881 allocate_slab mm/slub.c:2028 [inline] new_slab+0x87/0x2d0 mm/slub.c:2081 ___slab_alloc+0xc5c/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+0x11f/0x250 mm/slub.c:3534 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc_node_track_caller+0xa4/0x230 mm/slab_common.c:1027 kmalloc_reserve+0x116/0x240 net/core/skbuff.c:584 __alloc_skb+0x138/0x2c0 net/core/skbuff.c:653 alloc_skb include/linux/skbuff.h:1316 [inline] alloc_skb_with_frags+0xcd/0x7a0 net/core/skbuff.c:6353 sock_alloc_send_pskb+0x883/0x9a0 net/core/sock.c:2829 unix_dgram_sendmsg+0x5a9/0x16e0 net/unix/af_unix.c:2003 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] sock_write_iter+0x2dc/0x420 net/socket.c:1161 do_iter_readv_writev fs/read_write.c:-1 [inline] do_iter_write+0x747/0xc50 fs/read_write.c:860 vfs_writev fs/read_write.c:933 [inline] do_writev+0x27f/0x480 fs/read_write.c:976 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1182 [inline] free_unref_page_prepare+0x7d7/0x8f0 mm/page_alloc.c:2366 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2459 free_large_kmalloc+0x101/0x1b0 mm/slab_common.c:984 skb_kfree_head net/core/skbuff.c:946 [inline] skb_free_head net/core/skbuff.c:958 [inline] skb_release_data+0x609/0x7f0 net/core/skbuff.c:988 skb_release_all net/core/skbuff.c:1054 [inline] __kfree_skb net/core/skbuff.c:1068 [inline] consume_skb+0xb2/0x110 net/core/skbuff.c:1284 netlink_recvmsg+0x5e7/0xe60 net/netlink/af_netlink.c:1977 sock_recvmsg_nosec net/socket.c:1047 [inline] sock_recvmsg net/socket.c:1069 [inline] ____sys_recvmsg+0x2bd/0x5d0 net/socket.c:2814 ___sys_recvmsg+0x214/0x590 net/socket.c:2856 __sys_recvmsg net/socket.c:2886 [inline] __do_sys_recvmsg net/socket.c:2896 [inline] __se_sys_recvmsg net/socket.c:2893 [inline] __x64_sys_recvmsg+0x21e/0x2f0 net/socket.c:2893 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Memory state around the buggy address: ffff88802c7d3200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88802c7d3280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88802c7d3300: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc ^ ffff88802c7d3380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88802c7d3400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess): 0: 8b 1c 24 mov (%rsp),%ebx 3: 4c 8b 64 24 08 mov 0x8(%rsp),%r12 8: 48 83 c4 10 add $0x10,%rsp c: c3 ret d: cc int3 e: cc int3 f: cc int3 10: cc int3 11: cc int3 12: cc int3 13: cc int3 14: cc int3 15: f3 0f 1e fa endbr64 19: 48 83 f9 40 cmp $0x40,%rcx 1d: 73 40 jae 0x5f 1f: 83 f9 08 cmp $0x8,%ecx 22: 73 21 jae 0x45 24: 85 c9 test %ecx,%ecx 26: 74 0f je 0x37 28: 8a 06 mov (%rsi),%al * 2a: 88 07 mov %al,(%rdi) <-- trapping instruction 2c: 48 ff c7 inc %rdi 2f: 48 ff c6 inc %rsi 32: 48 ff c9 dec %rcx 35: 75 f1 jne 0x28 37: c3 ret 38: 66 data16 39: 2e cs 3a: 0f .byte 0xf 3b: 1f (bad) 3c: 84 00 test %al,(%rax)