================================================================== BUG: KASAN: use-after-free in instrument_atomic_read include/linux/instrumented.h:72 [inline] BUG: KASAN: use-after-free in atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline] BUG: KASAN: use-after-free in refcount_read include/linux/refcount.h:147 [inline] BUG: KASAN: use-after-free in tcp_metrics_flush_all+0xd3/0x210 net/ipv4/tcp_metrics.c:909 Read of size 4 at addr ffff88811166e98c by task syz.4.5921/30327 CPU: 1 PID: 30327 Comm: syz.4.5921 Tainted: G W 6.1.141-syzkaller-00034-g1bf1aa362e6b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: __dump_stack+0x21/0x24 lib/dump_stack.c:88 dump_stack_lvl+0xee/0x150 lib/dump_stack.c:106 print_address_description+0x71/0x210 mm/kasan/report.c:316 print_report+0x4a/0x60 mm/kasan/report.c:427 kasan_report+0x122/0x150 mm/kasan/report.c:531 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x280/0x290 mm/kasan/generic.c:189 __kasan_check_read+0x11/0x20 mm/kasan/shadow.c:31 instrument_atomic_read include/linux/instrumented.h:72 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline] refcount_read include/linux/refcount.h:147 [inline] tcp_metrics_flush_all+0xd3/0x210 net/ipv4/tcp_metrics.c:909 tcp_net_metrics_exit_batch+0x10/0x20 net/ipv4/tcp_metrics.c:1037 ops_exit_list net/core/net_namespace.c:177 [inline] setup_net+0x8cb/0xcb0 net/core/net_namespace.c:358 copy_net_ns+0x355/0x5c0 net/core/net_namespace.c:481 create_new_namespaces+0x3a2/0x660 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x120/0x170 kernel/nsproxy.c:226 ksys_unshare+0x4ac/0x7b0 kernel/fork.c:3388 __do_sys_unshare kernel/fork.c:3459 [inline] __se_sys_unshare kernel/fork.c:3457 [inline] __x64_sys_unshare+0x38/0x40 kernel/fork.c:3457 x64_sys_call+0x767/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:273 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f868178e929 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f868260c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f86819b6160 RCX: 00007f868178e929 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000064000600 RBP: 00007f8681810b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f86819b6160 R15: 00007ffe83b5b5f8 Allocated by task 16041: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_alloc_info+0x25/0x30 mm/kasan/generic.c:505 __kasan_slab_alloc+0x72/0x80 mm/kasan/common.c:333 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:3421 [inline] slab_alloc mm/slub.c:3431 [inline] __kmem_cache_alloc_lru mm/slub.c:3438 [inline] kmem_cache_alloc+0x16e/0x330 mm/slub.c:3447 kmem_cache_zalloc include/linux/slab.h:689 [inline] net_alloc net/core/net_namespace.c:413 [inline] copy_net_ns+0x145/0x5c0 net/core/net_namespace.c:468 create_new_namespaces+0x3a2/0x660 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x120/0x170 kernel/nsproxy.c:226 ksys_unshare+0x4ac/0x7b0 kernel/fork.c:3388 __do_sys_unshare kernel/fork.c:3459 [inline] __se_sys_unshare kernel/fork.c:3457 [inline] __x64_sys_unshare+0x38/0x40 kernel/fork.c:3457 x64_sys_call+0x767/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:273 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 27263: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x31/0x50 mm/kasan/generic.c:516 ____kasan_slab_free+0x132/0x180 mm/kasan/common.c:241 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:249 kasan_slab_free include/linux/kasan.h:178 [inline] slab_free_hook mm/slub.c:1745 [inline] slab_free_freelist_hook+0xc2/0x190 mm/slub.c:1771 slab_free mm/slub.c:3686 [inline] kmem_cache_free+0x12d/0x300 mm/slub.c:3711 net_free net/core/net_namespace.c:442 [inline] cleanup_net+0xa58/0xb00 net/core/net_namespace.c:625 process_one_work+0x71f/0xc40 kernel/workqueue.c:2299 worker_thread+0xa29/0x11f0 kernel/workqueue.c:2446 kthread+0x281/0x320 kernel/kthread.c:386 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb6/0xc0 mm/kasan/generic.c:486 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:496 insert_work+0x51/0x300 kernel/workqueue.c:1368 __queue_work+0x9b1/0xd30 kernel/workqueue.c:1527 delayed_work_timer_fn+0x61/0x80 kernel/workqueue.c:1653 call_timer_fn+0x46/0x2a0 kernel/time/timer.c:1510 expire_timers kernel/time/timer.c:1550 [inline] __run_timers+0x667/0x9a0 kernel/time/timer.c:1826 run_timer_softirq+0xb8/0xf0 kernel/time/timer.c:1841 handle_softirqs+0x1d7/0x600 kernel/softirq.c:642 __do_softirq kernel/softirq.c:680 [inline] invoke_softirq kernel/softirq.c:497 [inline] __irq_exit_rcu+0x52/0xf0 kernel/softirq.c:729 irq_exit_rcu+0x9/0x10 kernel/softirq.c:741 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0xa9/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:691 Second to last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb6/0xc0 mm/kasan/generic.c:486 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:496 insert_work+0x51/0x300 kernel/workqueue.c:1368 __queue_work+0x9b1/0xd30 kernel/workqueue.c:1527 delayed_work_timer_fn+0x61/0x80 kernel/workqueue.c:1653 call_timer_fn+0x46/0x2a0 kernel/time/timer.c:1510 expire_timers kernel/time/timer.c:1550 [inline] __run_timers+0x667/0x9a0 kernel/time/timer.c:1826 run_timer_softirq+0xb8/0xf0 kernel/time/timer.c:1841 handle_softirqs+0x1d7/0x600 kernel/softirq.c:642 __do_softirq kernel/softirq.c:680 [inline] invoke_softirq kernel/softirq.c:497 [inline] __irq_exit_rcu+0x52/0xf0 kernel/softirq.c:729 irq_exit_rcu+0x9/0x10 kernel/softirq.c:741 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0xa9/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x1b/0x20 arch/x86/include/asm/idtentry.h:691 The buggy address belongs to the object at ffff88811166e900 which belongs to the cache net_namespace of size 4224 The buggy address is located 140 bytes inside of 4224-byte region [ffff88811166e900, ffff88811166f980) The buggy address belongs to the physical page: page:ffffea0004459a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88811166d780 pfn:0x111668 head:ffffea0004459a00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x4000000000010200(slab|head|zone=1) raw: 4000000000010200 0000000000000000 dead000000000001 ffff8881002acc00 raw: ffff88811166d780 0000000080070005 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 285, tgid 285 (syz-executor), ts 25952120672, free_ts 25759208392 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2637 prep_new_page+0x1c/0x110 mm/page_alloc.c:2644 get_page_from_freelist+0x2c7b/0x2cf0 mm/page_alloc.c:4539 __alloc_pages+0x19e/0x3a0 mm/page_alloc.c:5850 alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1 allocate_slab mm/slub.c:1962 [inline] new_slab+0x98/0x3d0 mm/slub.c:2015 ___slab_alloc+0x6f6/0xb50 mm/slub.c:3203 __slab_alloc+0x5e/0xa0 mm/slub.c:3302 slab_alloc_node mm/slub.c:3387 [inline] slab_alloc mm/slub.c:3431 [inline] __kmem_cache_alloc_lru mm/slub.c:3438 [inline] kmem_cache_alloc+0x1b0/0x330 mm/slub.c:3447 kmem_cache_zalloc include/linux/slab.h:689 [inline] net_alloc net/core/net_namespace.c:413 [inline] copy_net_ns+0x145/0x5c0 net/core/net_namespace.c:468 create_new_namespaces+0x3a2/0x660 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x120/0x170 kernel/nsproxy.c:226 ksys_unshare+0x4ac/0x7b0 kernel/fork.c:3388 __do_sys_unshare kernel/fork.c:3459 [inline] __se_sys_unshare kernel/fork.c:3457 [inline] __x64_sys_unshare+0x38/0x40 kernel/fork.c:3457 x64_sys_call+0x767/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:273 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 page last free stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] free_pages_prepare mm/page_alloc.c:1545 [inline] free_pcp_prepare mm/page_alloc.c:1619 [inline] free_unref_page_prepare+0x742/0x750 mm/page_alloc.c:3581 free_unref_page+0x8f/0x530 mm/page_alloc.c:3677 free_the_page mm/page_alloc.c:830 [inline] free_compound_page+0x99/0xd0 mm/page_alloc.c:853 destroy_large_folio+0x68/0xa0 mm/page_alloc.c:890 __folio_put_large mm/swap.c:110 [inline] __folio_put+0xd1/0xe0 mm/swap.c:118 folio_put include/linux/mm.h:1431 [inline] put_page include/linux/mm.h:1483 [inline] __skb_frag_unref include/linux/skbuff.h:3455 [inline] skb_release_data+0x47f/0x890 net/core/skbuff.c:788 skb_release_all net/core/skbuff.c:859 [inline] napi_consume_skb+0x13d/0x2c0 net/core/skbuff.c:1116 skb_defer_free_flush net/core/dev.c:6745 [inline] net_rx_action+0x393/0xaa0 net/core/dev.c:6766 handle_softirqs+0x1d7/0x600 kernel/softirq.c:642 __do_softirq kernel/softirq.c:680 [inline] invoke_softirq kernel/softirq.c:497 [inline] __irq_exit_rcu+0x52/0xf0 kernel/softirq.c:729 irq_exit_rcu+0x9/0x10 kernel/softirq.c:741 common_interrupt+0xbe/0xe0 arch/x86/kernel/irq.c:242 asm_common_interrupt+0x27/0x40 arch/x86/include/asm/idtentry.h:682 Memory state around the buggy address: ffff88811166e880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88811166e900: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88811166e980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88811166ea00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88811166ea80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================