================================================================== BUG: KASAN: slab-out-of-bounds in __bpf_get_stackid+0x6c7/0x900 kernel/bpf/stackmap.c:271 Write of size 72 at addr ffff888020fdac90 by task syz.0.402/7181 CPU: 0 PID: 7181 Comm: syz.0.402 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:362 [inline] bpf_get_stackid_pe+0x343/0x410 kernel/bpf/stackmap.c:331 bpf_prog_a448e89f4c9ad9d1+0x30/0x4a 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_swevent_overflow kernel/events/core.c:9795 [inline] perf_swevent_event+0x319/0x570 kernel/events/core.c:9846 do_perf_sw_event kernel/events/core.c:9959 [inline] ___perf_sw_event+0x4ab/0x730 kernel/events/core.c:9990 __perf_sw_event+0x139/0x270 kernel/events/core.c:10002 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+0x4a/0x90 arch/x86/lib/copy_user_64.S:71 Code: 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 c9 a4 c3 48 8b 06 48 89 07 48 8d 47 08 48 83 e0 f8 48 29 f8 48 01 RSP: 0018:ffffc90019b4fbd0 EFLAGS: 00050206 RAX: ffffffff84320801 RBX: 000000000000056d RCX: 00000000000004ed RDX: 0000000000000001 RSI: 0000200000002000 RDI: ffff88805bb85080 RBP: ffffc90019b4fd20 R08: 0000000000000004 R09: 0000000000000005 R10: dffffc0000000000 R11: ffffed100b770aad R12: 00002000000024ed R13: 1ffff92003369fbd R14: ffff88805bb85000 R15: 0000200000001f80 copy_user_generic arch/x86/include/asm/uaccess_64.h:112 [inline] raw_copy_from_user arch/x86/include/asm/uaccess_64.h:127 [inline] _copy_from_user+0x8b/0xe0 lib/usercopy.c:23 copy_from_user include/linux/uaccess.h:183 [inline] generic_map_update_batch+0x58c/0x800 kernel/bpf/syscall.c:1797 bpf_map_do_batch+0x3f2/0x600 kernel/bpf/syscall.c:5011 __sys_bpf+0x381/0x890 kernel/bpf/syscall.c:-1 __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: 0033:0x7fc63119e0d9 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:00007fc632072028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fc631425fa0 RCX: 00007fc63119e0d9 RDX: 0000000000000038 RSI: 00002000000006c0 RDI: 000000000000001a RBP: 00007fc631235024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc631426038 R14: 00007fc631425fa0 R15: 00007ffdd1834f68 Allocated by task 7181: 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 __call_rcu_common kernel/rcu/tree.c:2721 [inline] call_rcu+0x153/0x900 kernel/rcu/tree.c:2837 nf_hook_entries_free net/netfilter/core.c:88 [inline] __nf_register_net_hook+0x787/0x910 net/netfilter/core.c:457 nf_register_net_hook+0xb2/0x190 net/netfilter/core.c:578 nf_register_net_hooks+0x44/0x1b0 net/netfilter/core.c:594 nf_ct_netns_do_get+0x3c0/0x5c0 net/netfilter/nf_conntrack_proto.c:457 nf_ct_netns_inet_get+0x1f/0x150 net/netfilter/nf_conntrack_proto.c:566 nf_conncount_init+0x127/0x380 net/netfilter/nf_conncount.c:639 ovs_ct_limit_init net/openvswitch/conntrack.c:1580 [inline] ovs_ct_init+0x316/0x490 net/openvswitch/conntrack.c:1989 ovs_init_net+0x1e6/0x250 net/openvswitch/datapath.c:2679 ops_init+0x391/0x640 net/core/net_namespace.c:139 setup_net+0x3b6/0xa20 net/core/net_namespace.c:343 copy_net_ns+0x35e/0x5d0 net/core/net_namespace.c:520 create_new_namespaces+0x3ce/0x700 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x11a/0x160 kernel/nsproxy.c:228 ksys_unshare+0x4fa/0x8f0 kernel/fork.c:3444 __do_sys_unshare kernel/fork.c:3518 [inline] __se_sys_unshare kernel/fork.c:3516 [inline] __x64_sys_unshare+0x38/0x40 kernel/fork.c:3516 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 ffff888020fdac80 which belongs to the cache kmalloc-cg-64 of size 64 The buggy address is located 16 bytes inside of allocated 40-byte region [ffff888020fdac80, ffff888020fdaca8) The buggy address belongs to the physical page: page:ffffea000083f680 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x20fda memcg:ffff88807fc57001 flags: 0xfff00000000800(slab|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000800 ffff888017c4da00 ffffea0000aecf40 0000000000000002 raw: 0000000000000000 0000000080200020 00000001ffffffff ffff88807fc57001 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x16cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_NORETRY), pid 5146, tgid 5146 (udevd), ts 30514431839, free_ts 30419830064 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] inotify_handle_inode_event+0x18a/0x560 fs/notify/inotify/inotify_fsnotify.c:96 fsnotify_handle_event fs/notify/fsnotify.c:311 [inline] send_to_group fs/notify/fsnotify.c:385 [inline] fsnotify+0x13a6/0x1800 fs/notify/fsnotify.c:591 __fsnotify_parent+0x655/0x7c0 fs/notify/fsnotify.c:248 notify_change+0xb3f/0xde0 fs/attr.c:504 chmod_common+0x257/0x400 fs/open.c:643 do_fchmodat+0x10c/0x1e0 fs/open.c:691 __do_sys_chmod fs/open.c:715 [inline] __se_sys_chmod fs/open.c:713 [inline] __x64_sys_chmod+0x62/0x70 fs/open.c:713 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 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_slab_alloc+0x22/0x80 mm/kasan/common.c:306 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6a/0x4d0 mm/slab.h:770 slab_alloc_node mm/slub.c:3495 [inline] __kmem_cache_alloc_node+0x194/0x250 mm/slub.c:3534 kmalloc_trace+0x2a/0xe0 mm/slab_common.c:1098 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:721 [inline] kernfs_iop_get_link+0x66/0x650 fs/kernfs/symlink.c:135 vfs_readlink+0x170/0x370 fs/namei.c:5176 do_readlinkat+0x255/0x490 fs/stat.c:506 __do_sys_readlink fs/stat.c:527 [inline] __se_sys_readlink fs/stat.c:524 [inline] __x64_sys_readlink+0x7f/0x90 fs/stat.c:524 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 Memory state around the buggy address: ffff888020fdab80: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888020fdac00: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff888020fdac80: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc ^ ffff888020fdad00: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888020fdad80: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess): 0: 75 f1 jne 0xfffffff3 2: c3 ret 3: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1) a: 00 00 00 d: 0f 1f 00 nopl (%rax) 10: 48 8b 06 mov (%rsi),%rax 13: 48 89 07 mov %rax,(%rdi) 16: 48 83 c6 08 add $0x8,%rsi 1a: 48 83 c7 08 add $0x8,%rdi 1e: 83 e9 08 sub $0x8,%ecx 21: 74 df je 0x2 23: 83 f9 08 cmp $0x8,%ecx 26: 73 e8 jae 0x10 28: eb c9 jmp 0xfffffff3 * 2a: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) <-- trapping instruction 2c: c3 ret 2d: 48 8b 06 mov (%rsi),%rax 30: 48 89 07 mov %rax,(%rdi) 33: 48 8d 47 08 lea 0x8(%rdi),%rax 37: 48 83 e0 f8 and $0xfffffffffffffff8,%rax 3b: 48 29 f8 sub %rdi,%rax 3e: 48 rex.W 3f: 01 .byte 0x1