================================================================== BUG: KASAN: slab-out-of-bounds in stack_map_get_build_id_offset+0x833/0x9b0 kernel/bpf/stackmap.c:147 Write of size 4 at addr ffff88811bc91b30 by task syz.1.58/553 CPU: 0 PID: 553 Comm: syz.1.58 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 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 __asan_report_store4_noabort+0x17/0x20 mm/kasan/report_generic.c:355 stack_map_get_build_id_offset+0x833/0x9b0 kernel/bpf/stackmap.c:147 __bpf_get_stackid+0x5ac/0x960 kernel/bpf/stackmap.c:250 ____bpf_get_stackid_pe kernel/bpf/stackmap.c:365 [inline] bpf_get_stackid_pe+0x2ee/0x400 kernel/bpf/stackmap.c:334 bpf_prog_2414a5d5030ea31b+0x21/0x25 bpf_dispatcher_nop_func include/linux/bpf.h:987 [inline] __bpf_prog_run include/linux/filter.h:607 [inline] bpf_prog_run include/linux/filter.h:614 [inline] bpf_overflow_handler+0x3c7/0x5e0 kernel/events/core.c:10273 __perf_event_overflow+0x458/0x640 kernel/events/core.c:9448 perf_swevent_overflow kernel/events/core.c:9531 [inline] perf_swevent_event+0x243/0x440 kernel/events/core.c:9582 do_perf_sw_event kernel/events/core.c:9695 [inline] ___perf_sw_event+0x3bf/0x500 kernel/events/core.c:9726 __perf_sw_event+0x134/0x270 kernel/events/core.c:9738 perf_sw_event include/linux/perf_event.h:1250 [inline] do_user_addr_fault+0xfe9/0x1030 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:copy_user_enhanced_fast_string+0x27/0x40 Code: ca eb 20 0f 01 cb 83 fa 40 72 38 89 d1 f3 a4 31 c0 0f 01 ca c3 89 ca eb 0a 90 90 90 90 90 90 90 90 90 90 83 f8 12 74 0a 89 d1 a4 89 c8 0f 01 ca c3 89 d0 0f 01 ca c3 01 ca eb e7 90 90 90 90 RSP: 0018:ffffc9002f5ffad8 EFLAGS: 00050287 RAX: 000000000000000e RBX: 000000000000000c RCX: 000000000000000c RDX: 000000000000000c RSI: ffff88811bc7e214 RDI: 0000000000000000 RBP: ffffc9002f5ffb00 R08: 3a6e6f6973726576 R09: 1ffff1102378fc43 R10: dffffc0000000000 R11: ffffed102378fc44 R12: 00007fffffffeff4 R13: 000000000000000c R14: 0000000000000000 R15: ffff88811bc7e214 copy_to_user include/linux/uaccess.h:169 [inline] bpf_verifier_vlog+0x179/0x390 kernel/bpf/log.c:34 __btf_verifier_log+0xdf/0x130 kernel/bpf/btf.c:1374 btf_verifier_log_hdr kernel/bpf/btf.c:1536 [inline] btf_parse_hdr+0x38a/0x800 kernel/bpf/btf.c:4922 btf_parse kernel/bpf/btf.c:5047 [inline] btf_new_fd+0x398/0x7a0 kernel/bpf/btf.c:6928 bpf_btf_load+0x6f/0x90 kernel/bpf/syscall.c:4362 __sys_bpf+0x5d5/0x850 kernel/bpf/syscall.c:5051 __do_sys_bpf kernel/bpf/syscall.c:5110 [inline] __se_sys_bpf kernel/bpf/syscall.c:5108 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5108 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 RIP: 0033:0x7f427859e159 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:00007f4276fd6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f4278826090 RCX: 00007f427859e159 RDX: 0000000000000020 RSI: 0000200000000200 RDI: 0000000000000012 RBP: 00007f427863503b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4278826128 R14: 00007f4278826090 R15: 00007fff046ed7d8 Allocated by task 553: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:53 kasan_save_alloc_info+0x1f/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+0x398/0x520 kernel/bpf/stackmap.c:117 find_and_alloc_map kernel/bpf/syscall.c:133 [inline] map_create+0x467/0xcf0 kernel/bpf/syscall.c:1126 __sys_bpf+0x34e/0x850 kernel/bpf/syscall.c:4988 __do_sys_bpf kernel/bpf/syscall.c:5110 [inline] __se_sys_bpf kernel/bpf/syscall.c:5108 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5108 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 ffff88811bc91800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 816 bytes inside of 1024-byte region [ffff88811bc91800, ffff88811bc91c00) The buggy address belongs to the physical page: page:ffffea00046f2400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11bc90 head:ffffea00046f2400 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head|zone=1) raw: 4000000000010200 0000000000000000 dead000000000122 ffff888100043080 raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 280, tgid 280 (syz-executor), ts 35905962044, free_ts 34897974048 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2673 prep_new_page+0x1c/0x110 mm/page_alloc.c:2680 get_page_from_freelist+0x2ca9/0x2d20 mm/page_alloc.c:4587 __alloc_pages+0x1fa/0x610 mm/page_alloc.c:5931 alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1 allocate_slab mm/slub.c:1967 [inline] new_slab+0x98/0x3e0 mm/slub.c:2020 ___slab_alloc+0x70f/0xb70 mm/slub.c:3177 __slab_alloc+0x5e/0xa0 mm/slub.c:3263 slab_alloc_node mm/slub.c:3348 [inline] __kmem_cache_alloc_node+0x204/0x2d0 mm/slub.c:3423 __do_kmalloc_node mm/slab_common.c:937 [inline] __kmalloc_node_track_caller+0xa1/0x1e0 mm/slab_common.c:958 kmalloc_reserve net/core/skbuff.c:449 [inline] __alloc_skb+0x226/0x4a0 net/core/skbuff.c:518 alloc_skb_fclone include/linux/skbuff.h:1372 [inline] tcp_stream_alloc_skb+0x47/0x360 net/ipv4/tcp.c:871 tcp_sendmsg_locked+0xcb7/0x39f0 net/ipv4/tcp.c:1334 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1492 inet_sendmsg+0xb6/0xd0 net/ipv4/af_inet.c:841 sock_sendmsg_nosec net/socket.c:716 [inline] __sock_sendmsg net/socket.c:728 [inline] sock_write_iter+0x2ea/0x3f0 net/socket.c:1134 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1581 [inline] free_pcp_prepare mm/page_alloc.c:1655 [inline] free_unref_page_prepare+0x81b/0x820 mm/page_alloc.c:3622 free_unref_page+0x93/0x530 mm/page_alloc.c:3720 free_the_page mm/page_alloc.c:863 [inline] __free_pages+0x67/0x100 mm/page_alloc.c:6021 __free_slab+0xc7/0x1a0 mm/slub.c:2044 free_slab mm/slub.c:2059 [inline] discard_slab mm/slub.c:2065 [inline] __unfreeze_partials+0x15a/0x190 mm/slub.c:2614 put_cpu_partial+0xa9/0x100 mm/slub.c:2690 __slab_free+0x1c4/0x280 mm/slub.c:3589 do_slab_free mm/slub.c:3666 [inline] ___cache_free+0xbf/0xd0 mm/slub.c:3722 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0xc6/0x140 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x14a/0x170 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x24/0x80 mm/kasan/common.c:311 kasan_slab_alloc include/linux/kasan.h:202 [inline] slab_post_alloc_hook+0x4f/0x2d0 mm/slab.h:768 slab_alloc_node mm/slub.c:3382 [inline] slab_alloc mm/slub.c:3392 [inline] __kmem_cache_alloc_lru mm/slub.c:3399 [inline] kmem_cache_alloc+0x166/0x320 mm/slub.c:3408 kmem_cache_zalloc include/linux/slab.h:689 [inline] taskstats_tgid_alloc kernel/taskstats.c:583 [inline] taskstats_exit+0x1f0/0xb50 kernel/taskstats.c:622 do_exit+0x8aa/0x2970 kernel/exit.c:870 do_group_exit+0x21b/0x2e0 kernel/exit.c:1038 Memory state around the buggy address: ffff88811bc91a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88811bc91a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88811bc91b00: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc ^ ffff88811bc91b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88811bc91c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess): 0: ca eb 20 lret $0x20eb 3: 0f 01 cb stac 6: 83 fa 40 cmp $0x40,%edx 9: 72 38 jb 0x43 b: 89 d1 mov %edx,%ecx d: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) f: 31 c0 xor %eax,%eax 11: 0f 01 ca clac 14: c3 ret 15: 89 ca mov %ecx,%edx 17: eb 0a jmp 0x23 19: 90 nop 1a: 90 nop 1b: 90 nop 1c: 90 nop 1d: 90 nop 1e: 90 nop 1f: 90 nop 20: 90 nop 21: 90 nop 22: 90 nop 23: 83 f8 12 cmp $0x12,%eax 26: 74 0a je 0x32 28: 89 d1 mov %edx,%ecx * 2a: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) <-- trapping instruction 2c: 89 c8 mov %ecx,%eax 2e: 0f 01 ca clac 31: c3 ret 32: 89 d0 mov %edx,%eax 34: 0f 01 ca clac 37: c3 ret 38: 01 ca add %ecx,%edx 3a: eb e7 jmp 0x23 3c: 90 nop 3d: 90 nop 3e: 90 nop 3f: 90 nop