================================================================== BUG: KASAN: slab-out-of-bounds in __bpf_get_stackid+0x6c7/0x900 kernel/bpf/stackmap.c:271 Write of size 32 at addr ffff88802edf1460 by task syz.3.1025/8326 CPU: 1 PID: 8326 Comm: syz.3.1025 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 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x241/0x290 mm/kasan/generic.c:187 __asan_memcpy+0x40/0x70 mm/kasan/shadow.c:106 __bpf_get_stackid+0x6c7/0x900 kernel/bpf/stackmap.c:271 ____bpf_get_stackid_pe kernel/bpf/stackmap.c:374 [inline] bpf_get_stackid_pe+0x2f0/0x410 kernel/bpf/stackmap.c:331 bpf_prog_d499e7ac612d6085+0x2c/0x44 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:10576 __perf_event_overflow+0x461/0x660 kernel/events/core.c:9712 perf_event_overflow kernel/events/core.c:9733 [inline] perf_swevent_hrtimer+0x437/0x610 kernel/events/core.c:11222 __run_hrtimer kernel/time/hrtimer.c:1754 [inline] __hrtimer_run_queues+0x4e8/0xc10 kernel/time/hrtimer.c:1818 hrtimer_interrupt+0x39d/0x980 kernel/time/hrtimer.c:1880 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline] __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0x51/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0033:0x7ffdacfa9a25 Code: a7 4c 29 d2 48 0f ba e2 3e 0f 82 ad 00 00 00 48 bf ff ff ff ff ff ff ff 7f 48 21 fa 49 0f af d1 48 01 c2 48 d3 ea 48 89 55 c0 <31> c0 48 81 fa 00 ca 9a 3b 72 1c 31 c9 48 81 c2 00 36 65 c4 48 89 RSP: 002b:00007f7427ee1ff0 EFLAGS: 00000206 RAX: 0034e82664b8acf2 RBX: 00007ffdacfa50b0 RCX: 0000000000000018 RDX: 000000003596ba24 RSI: 00007f7427ee20b0 RDI: 7fffffffffffffff RBP: 00007f7427ee2030 R08: 00000000000000dd R09: 0000000000745d1e R10: 000000748545e7e3 R11: 000000000000a858 R12: 0000000000000010 R13: 00007f7427226038 R14: 00007ffdacfa5080 R15: 000000000000a858 Allocated by task 8326: 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 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 kvfree_call_rcu+0xee/0x780 kernel/rcu/tree.c:3452 drop_sysctl_table+0x394/0x540 fs/proc/proc_sysctl.c:1515 unregister_sysctl_table+0x41/0x60 fs/proc/proc_sysctl.c:1536 mpls_dev_sysctl_unregister+0x8b/0xc0 net/mpls/af_mpls.c:1431 mpls_dev_notify+0x533/0x7a0 net/mpls/af_mpls.c:1643 notifier_call_chain+0x18f/0x380 kernel/notifier.c:93 call_netdevice_notifiers_extack net/core/dev.c:2077 [inline] call_netdevice_notifiers net/core/dev.c:2091 [inline] unregister_netdevice_many_notify+0x1037/0x1910 net/core/dev.c:11124 unregister_netdevice_many net/core/dev.c:11180 [inline] unregister_netdevice_queue+0x2e9/0x330 net/core/dev.c:11060 unregister_netdevice include/linux/netdevice.h:3139 [inline] __tun_detach+0xdb2/0x1580 drivers/net/tun.c:685 tun_detach drivers/net/tun.c:701 [inline] tun_chr_close+0x10d/0x1c0 drivers/net/tun.c:3514 __fput+0x221/0x940 fs/file_table.c:418 task_work_run+0x1d4/0x260 kernel/task_work.c:245 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 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 kvfree_call_rcu+0xee/0x780 kernel/rcu/tree.c:3452 drop_sysctl_table+0x394/0x540 fs/proc/proc_sysctl.c:1515 unregister_sysctl_table+0x41/0x60 fs/proc/proc_sysctl.c:1536 mpls_dev_sysctl_unregister+0x8b/0xc0 net/mpls/af_mpls.c:1431 mpls_dev_notify+0x533/0x7a0 net/mpls/af_mpls.c:1643 notifier_call_chain+0x18f/0x380 kernel/notifier.c:93 call_netdevice_notifiers_extack net/core/dev.c:2077 [inline] call_netdevice_notifiers net/core/dev.c:2091 [inline] unregister_netdevice_many_notify+0x1037/0x1910 net/core/dev.c:11124 unregister_netdevice_many net/core/dev.c:11180 [inline] unregister_netdevice_queue+0x2e9/0x330 net/core/dev.c:11060 unregister_netdevice include/linux/netdevice.h:3139 [inline] __tun_detach+0xdb2/0x1580 drivers/net/tun.c:685 tun_detach drivers/net/tun.c:701 [inline] tun_chr_close+0x10d/0x1c0 drivers/net/tun.c:3514 __fput+0x221/0x940 fs/file_table.c:418 task_work_run+0x1d4/0x260 kernel/task_work.c:245 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 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 ffff88802edf1400 which belongs to the cache kmalloc-cg-128 of size 128 The buggy address is located 96 bytes inside of allocated 120-byte region [ffff88802edf1400, ffff88802edf1478) The buggy address belongs to the physical page: page:ffffea0000bb7c40 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2edf1 memcg:ffff888023aee701 flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000800 ffff888017c4dc80 ffffea00006fd700 0000000000000002 raw: 0000000000000000 0000000080100010 00000001ffffffff ffff888023aee701 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 6041, tgid 6040 (syz.2.76), ts 101385681730, free_ts 101040242793 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+0xa7/0x240 mm/slab_common.c:1020 kmalloc include/linux/slab.h:604 [inline] kzalloc include/linux/slab.h:721 [inline] __register_sysctl_table+0x71/0x1210 fs/proc/proc_sysctl.c:1373 mpls_dev_sysctl_register+0x207/0x2f0 net/mpls/af_mpls.c:1406 mpls_add_dev net/mpls/af_mpls.c:1462 [inline] mpls_dev_notify+0x357/0x7a0 net/mpls/af_mpls.c:1602 notifier_call_chain+0x18f/0x380 kernel/notifier.c:93 call_netdevice_notifiers_extack net/core/dev.c:2077 [inline] call_netdevice_notifiers net/core/dev.c:2091 [inline] register_netdevice+0x1670/0x1ba0 net/core/dev.c:10351 tun_set_iff+0x82b/0xea0 drivers/net/tun.c:2865 __tun_chr_ioctl+0x7e0/0x2070 drivers/net/tun.c:3134 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857 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 discard_slab mm/slub.c:2127 [inline] __unfreeze_partials+0x1cf/0x210 mm/slub.c:2667 put_cpu_partial+0x17c/0x250 mm/slub.c:2743 __slab_free+0x319/0x400 mm/slub.c:3700 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xd0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292 ____kasan_kmalloc mm/kasan/common.c:341 [inline] __kasan_kmalloc+0x22/0xa0 mm/kasan/common.c:384 kasan_kmalloc include/linux/kasan.h:198 [inline] __do_kmalloc_node mm/slab_common.c:1007 [inline] __kmalloc+0xb7/0x240 mm/slab_common.c:1020 kmalloc_array include/linux/slab.h:637 [inline] kcalloc include/linux/slab.h:668 [inline] ext4_find_extent+0x1f5/0xcd0 fs/ext4/extents.c:925 ext4_ext_map_blocks+0x292/0x68c0 fs/ext4/extents.c:4244 ext4_map_blocks+0x9db/0x1a90 fs/ext4/inode.c:654 ext4_convert_unwritten_extents+0x2c0/0x5e0 fs/ext4/extents.c:4945 ext4_convert_unwritten_io_end_vec+0xff/0x170 fs/ext4/extents.c:4984 ext4_end_io_end fs/ext4/page-io.c:194 [inline] ext4_do_flush_completed_IO fs/ext4/page-io.c:269 [inline] ext4_end_io_rsv_work+0x2af/0x640 fs/ext4/page-io.c:283 process_one_work kernel/workqueue.c:2657 [inline] process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2734 Memory state around the buggy address: ffff88802edf1300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802edf1380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88802edf1400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc ^ ffff88802edf1480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88802edf1500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc ==================================================================