================================================================== 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 ffff888025fdeb30 by task syz.0.2192/12533 CPU: 1 PID: 12533 Comm: syz.0.2192 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+0x33/0x90 arch/x86/lib/copy_user_64.S:58 Code: 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 00 00 0f 1f 00 48 8b 06 <48> 89 07 48 83 c6 08 48 83 c7 08 83 e9 08 74 df 83 f9 08 73 e8 eb RSP: 0018:ffffc9001939ed50 EFLAGS: 00050212 RAX: 3d65707974203152 RBX: 0000000000000016 RCX: 0000000000000016 RDX: 0000000000000000 RSI: ffff88805f33068c RDI: 000000000000cf3d RBP: ffff88805f330668 R08: ffff88805f3306a1 R09: 1ffff1100be660d4 R10: dffffc0000000000 R11: ffffed100be660d5 R12: 000000000000cf53 R13: 0000000000000016 R14: 000000000000cf3d R15: ffff88805f33068c 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+0x432/0x840 kernel/bpf/log.c:87 verbose+0x11e/0x1a0 kernel/bpf/verifier.c:370 check_reg_type kernel/bpf/verifier.c:8313 [inline] check_func_arg kernel/bpf/verifier.c:8610 [inline] check_helper_call+0x597f/0x6340 kernel/bpf/verifier.c:10146 do_check+0x87fb/0xd0a0 kernel/bpf/verifier.c:17478 do_check_common+0xacc/0x1410 kernel/bpf/verifier.c:19903 do_check_main kernel/bpf/verifier.c:19966 [inline] bpf_check+0x65df/0xec40 kernel/bpf/verifier.c:20646 bpf_prog_load+0x10fa/0x1610 kernel/bpf/syscall.c:2753 __sys_bpf+0x5ba/0x890 kernel/bpf/syscall.c:5491 __do_sys_bpf kernel/bpf/syscall.c:5595 [inline] __se_sys_bpf kernel/bpf/syscall.c:5593 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5593 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: 0033:0x7f1ea559e159 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:00007f1ea6415028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f1ea5826090 RCX: 00007f1ea559e159 RDX: 0000000000000023 RSI: 000020000000e000 RDI: 0000000000000005 RBP: 00007f1ea563506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1ea5826128 R14: 00007f1ea5826090 R15: 00007ffc8ec39c08 Allocated by task 12532: 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:5473 __do_sys_bpf kernel/bpf/syscall.c:5595 [inline] __se_sys_bpf kernel/bpf/syscall.c:5593 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5593 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 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492 insert_work+0x3d/0x310 kernel/workqueue.c:1674 __queue_work+0xbfd/0xfd0 kernel/workqueue.c:1823 queue_work_on+0x128/0x1f0 kernel/workqueue.c:1858 bpf_map_put_with_uref kernel/bpf/syscall.c:772 [inline] bpf_map_release+0x119/0x130 kernel/bpf/syscall.c:782 __fput+0x221/0x940 fs/file_table.c:418 task_work_run+0x1d4/0x260 kernel/task_work.c:245 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x986/0x2530 kernel/exit.c:890 do_group_exit+0x22d/0x2f0 kernel/exit.c:1032 get_signal+0x12a6/0x1390 kernel/signal.c:2915 arch_do_signal_or_restart+0xc2/0x7b0 arch/x86/kernel/signal.c:310 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:294 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:305 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Second to last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:46 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492 insert_work+0x3d/0x310 kernel/workqueue.c:1674 __queue_work+0xbfd/0xfd0 kernel/workqueue.c:1823 queue_work_on+0x128/0x1f0 kernel/workqueue.c:1858 bpf_map_put_with_uref kernel/bpf/syscall.c:772 [inline] bpf_map_release+0x119/0x130 kernel/bpf/syscall.c:782 __fput+0x221/0x940 fs/file_table.c:418 task_work_run+0x1d4/0x260 kernel/task_work.c:245 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x986/0x2530 kernel/exit.c:890 do_group_exit+0x22d/0x2f0 kernel/exit.c:1032 get_signal+0x12a6/0x1390 kernel/signal.c:2915 arch_do_signal_or_restart+0xc2/0x7b0 arch/x86/kernel/signal.c:310 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:294 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:305 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff888025fde800 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 [ffff888025fde800, ffff888025fdeb30) The buggy address belongs to the physical page: page:ffffea000097f600 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x25fd8 head:ffffea000097f600 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff888025175e01 flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888017c4f280 ffffea0001ebe600 dead000000000002 raw: 0000000000000000 0000000080100010 00000001ffffffff ffff888025175e01 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 5435, tgid 5435 (dhcpcd), ts 77423989914, free_ts 77422164294 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:6355 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 page_to_skb+0x735/0x8a0 drivers/net/virtio_net.c:612 receive_mergeable drivers/net/virtio_net.c:1707 [inline] receive_buf+0x321/0x3610 drivers/net/virtio_net.c:1839 virtnet_receive drivers/net/virtio_net.c:2159 [inline] virtnet_poll+0x69e/0x1300 drivers/net/virtio_net.c:2236 __napi_poll+0xbb/0x460 net/core/dev.c:6674 napi_poll net/core/dev.c:6741 [inline] net_rx_action+0x65f/0xcc0 net/core/dev.c:6877 handle_softirqs+0x27d/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 common_interrupt+0xb9/0xd0 arch/x86/kernel/irq.c:249 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:678 Memory state around the buggy address: ffff888025fdea00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888025fdea80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888025fdeb00: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc ^ ffff888025fdeb80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888025fdec00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess): 0: 40 83 f9 08 rex cmp $0x8,%ecx 4: 73 21 jae 0x27 6: 85 c9 test %ecx,%ecx 8: 74 0f je 0x19 a: 8a 06 mov (%rsi),%al c: 88 07 mov %al,(%rdi) e: 48 ff c7 inc %rdi 11: 48 ff c6 inc %rsi 14: 48 ff c9 dec %rcx 17: 75 f1 jne 0xa 19: c3 ret 1a: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1) 21: 00 00 00 24: 0f 1f 00 nopl (%rax) 27: 48 8b 06 mov (%rsi),%rax * 2a: 48 89 07 mov %rax,(%rdi) <-- trapping instruction 2d: 48 83 c6 08 add $0x8,%rsi 31: 48 83 c7 08 add $0x8,%rdi 35: 83 e9 08 sub $0x8,%ecx 38: 74 df je 0x19 3a: 83 f9 08 cmp $0x8,%ecx 3d: 73 e8 jae 0x27 3f: eb .byte 0xeb