================================================================== BUG: KASAN: slab-out-of-bounds in stack_map_get_build_id_offset+0x988/0x9b0 kernel/bpf/stackmap.c:147 Write of size 4 at addr ffff88811d4e4330 by task syz.0.1455/6584 CPU: 1 PID: 6584 Comm: syz.0.1455 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+0x988/0x9b0 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:596 [inline] bpf_prog_run include/linux/filter.h:614 [inline] bpf_overflow_handler+0x521/0x5e0 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_short_string+0xd/0x40 arch/x86/lib/copy_user_64.S:233 Code: 74 0a 89 d1 f3 a4 89 c8 0f 01 ca c3 89 d0 0f 01 ca c3 01 ca eb e7 90 90 90 90 90 90 90 89 d1 83 e2 07 c1 e9 03 74 12 4c 8b 06 <4c> 89 07 48 8d 76 08 48 8d 7f 08 ff c9 75 ee 21 d2 74 10 89 d1 8a RSP: 0018:ffffc90000f6f298 EFLAGS: 00050202 RAX: ffffffff82692d01 RBX: 000000000000000b RCX: 0000000000000001 RDX: 0000000000000003 RSI: ffff88812858466c RDI: 000000000000cf3d RBP: ffffc90000f6f2c0 R08: 40203023636e7566 R09: 1ffff110250b08ce R10: dffffc0000000000 R11: ffffed10250b08cf R12: 00007fffffffeff5 R13: 000000000000000b R14: 000000000000cf3d R15: ffff88812858466c copy_to_user include/linux/uaccess.h:169 [inline] bpf_verifier_vlog+0x179/0x390 kernel/bpf/log.c:34 verbose+0x1f0/0x2b0 kernel/bpf/verifier.c:303 add_subprog_and_kfunc kernel/bpf/verifier.c:2165 [inline] bpf_check+0x2f1b/0x10e90 kernel/bpf/verifier.c:15549 bpf_prog_load+0x10f4/0x1670 kernel/bpf/syscall.c:2624 __sys_bpf+0x57b/0x850 kernel/bpf/syscall.c:5006 __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: 0033:0x7ff71d99e159 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:00007ff71c3f7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007ff71dc25fa0 RCX: 00007ff71d99e159 RDX: 0000000000000023 RSI: 000020000000e000 RDI: 0000000000000005 RBP: 00007ff71da3503b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff71dc26038 R14: 00007ff71dc25fa0 R15: 00007ffe0b1cf8f8 Allocated by task 6584: 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 Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xb6/0xc0 mm/kasan/generic.c:486 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:496 __call_rcu_common kernel/rcu/tree.c:2807 [inline] call_rcu+0xcf/0xf50 kernel/rcu/tree.c:2926 rhashtable_rehash_table lib/rhashtable.c:345 [inline] rht_deferred_worker+0x108f/0x15d0 lib/rhashtable.c:429 process_one_work+0x717/0xc30 kernel/workqueue.c:2302 worker_thread+0xa4d/0x11d0 kernel/workqueue.c:2449 kthread+0x281/0x320 kernel/kthread.c:386 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 The buggy address belongs to the object at ffff88811d4e4000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 816 bytes inside of 1024-byte region [ffff88811d4e4000, ffff88811d4e4400) The buggy address belongs to the physical page: page:ffffea0004753800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11d4e0 head:ffffea0004753800 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head|zone=1) raw: 4000000000010200 dead000000000100 dead000000000122 ffff888100043080 raw: 0000000000000000 0000000000100010 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 0x152a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 5785, tgid 5780 (syz.1.1256), ts 165065873863, free_ts 165065594606 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 kmalloc_trace+0x29/0xb0 mm/slab_common.c:1028 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [inline] alloc_sk_msg net/core/skmsg.c:522 [inline] sk_psock_skb_ingress_self+0x63/0x3b0 net/core/skmsg.c:624 sk_psock_verdict_apply net/core/skmsg.c:1055 [inline] sk_psock_verdict_recv+0x5bb/0x7b0 net/core/skmsg.c:1251 unix_read_skb+0xd2/0x120 net/unix/af_unix.c:2567 sk_psock_verdict_data_ready+0xaf/0x1d0 net/core/skmsg.c:1266 unix_dgram_sendmsg+0x1089/0x1710 net/unix/af_unix.c:2089 sock_sendmsg_nosec net/socket.c:716 [inline] __sock_sendmsg net/socket.c:728 [inline] ____sys_sendmsg+0x5fb/0x9c0 net/socket.c:2509 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_compound_page+0x99/0xd0 mm/page_alloc.c:886 destroy_large_folio+0x68/0xa0 mm/page_alloc.c:923 __folio_put_large mm/swap.c:113 [inline] __folio_put+0xd1/0xe0 mm/swap.c:121 folio_put include/linux/mm.h:1442 [inline] put_page include/linux/mm.h:1494 [inline] __skb_frag_unref include/linux/skbuff.h:3510 [inline] skb_release_data+0x3d5/0x8a0 net/core/skbuff.c:788 skb_release_all net/core/skbuff.c:859 [inline] __kfree_skb net/core/skbuff.c:873 [inline] consume_skb+0xab/0x1f0 net/core/skbuff.c:1038 kfree_sk_msg include/linux/skmsg.h:376 [inline] __sk_msg_recvmsg+0xba2/0xd40 net/core/skmsg.c:488 sk_msg_recvmsg+0x38/0x50 net/core/skmsg.c:500 unix_bpf_recvmsg+0x45c/0xc30 net/unix/unix_bpf.c:76 unix_dgram_recvmsg+0xaf/0xe0 net/unix/af_unix.c:2550 ____sys_recvmsg+0x2d6/0x5c0 net/socket.c:-1 ___sys_recvmsg+0x210/0x590 net/socket.c:2770 __sys_recvmsg net/socket.c:2800 [inline] __do_sys_recvmsg net/socket.c:2810 [inline] __se_sys_recvmsg net/socket.c:2807 [inline] __x64_sys_recvmsg+0x20a/0x2e0 net/socket.c:2807 x64_sys_call+0x75/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:48 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 Memory state around the buggy address: ffff88811d4e4200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88811d4e4280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88811d4e4300: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc ^ ffff88811d4e4380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88811d4e4400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess): 0: 74 0a je 0xc 2: 89 d1 mov %edx,%ecx 4: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) 6: 89 c8 mov %ecx,%eax 8: 0f 01 ca clac b: c3 ret c: 89 d0 mov %edx,%eax e: 0f 01 ca clac 11: c3 ret 12: 01 ca add %ecx,%edx 14: eb e7 jmp 0xfffffffd 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: 90 nop 1b: 90 nop 1c: 90 nop 1d: 89 d1 mov %edx,%ecx 1f: 83 e2 07 and $0x7,%edx 22: c1 e9 03 shr $0x3,%ecx 25: 74 12 je 0x39 27: 4c 8b 06 mov (%rsi),%r8 * 2a: 4c 89 07 mov %r8,(%rdi) <-- trapping instruction 2d: 48 8d 76 08 lea 0x8(%rsi),%rsi 31: 48 8d 7f 08 lea 0x8(%rdi),%rdi 35: ff c9 dec %ecx 37: 75 ee jne 0x27 39: 21 d2 and %edx,%edx 3b: 74 10 je 0x4d 3d: 89 d1 mov %edx,%ecx 3f: 8a .byte 0x8a