================================================================== BUG: KASAN: use-after-free in rose_timer_expiry+0x470/0x490 net/rose/rose_timer.c:183 Read of size 2 at addr ffff88807d73242a by task syz.2.908/9330 CPU: 1 PID: 9330 Comm: syz.2.908 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 print_address_description+0x60/0x2d0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0xdf/0x130 mm/kasan/report.c:451 rose_timer_expiry+0x470/0x490 net/rose/rose_timer.c:183 call_timer_fn+0x17b/0x540 kernel/time/timer.c:1451 expire_timers kernel/time/timer.c:1496 [inline] __run_timers+0x53a/0x7f0 kernel/time/timer.c:1767 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780 handle_softirqs+0x339/0x830 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:lock_acquire+0x208/0x400 kernel/locking/lockdep.c:5627 Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f1 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 43 c7 44 3d 08 00 00 00 00 65 48 8b 04 RSP: 0018:ffffc90003a675a0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: c7353c4ed35d8900 RDX: 0000000000000000 RSI: ffffffff8a2b2ea0 RDI: ffffffff8a79ec00 RBP: ffffc90003a676a8 R08: dffffc0000000000 R09: 1ffffffff2037218 R10: dffffc0000000000 R11: fffffbfff2037219 R12: ffffffff8c31c720 R13: 1ffff9200074cec0 R14: 0000000000000246 R15: dffffc0000000000 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313 rcu_read_lock include/linux/rcupdate.h:740 [inline] sk_filter_trim_cap+0x14c/0x810 net/core/filter.c:146 sk_filter include/linux/filter.h:935 [inline] unix_dgram_sendmsg+0xafc/0x18a0 net/unix/af_unix.c:1840 sock_sendmsg_nosec net/socket.c:706 [inline] __sock_sendmsg net/socket.c:718 [inline] ____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2445 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2499 __sys_sendmmsg+0x2ba/0x500 net/socket.c:2585 __do_sys_sendmmsg net/socket.c:2614 [inline] __se_sys_sendmmsg net/socket.c:2611 [inline] __x64_sys_sendmmsg+0x9c/0xb0 net/socket.c:2611 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fc8ffdcccb9 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:00007fc8fe028028 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007fc900047fa0 RCX: 00007fc8ffdcccb9 RDX: 0000000000000651 RSI: 0000200000000000 RDI: 0000000000000004 RBP: 00007fc8ffe3abf7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc900048038 R14: 00007fc900047fa0 R15: 00007ffe31a118c8 Allocated by task 4197: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] __kasan_kmalloc+0xb5/0xf0 mm/kasan/common.c:522 kmalloc_reserve net/core/skbuff.c:356 [inline] __alloc_skb+0x22c/0x750 net/core/skbuff.c:427 __napi_alloc_skb+0x151/0x2d0 net/core/skbuff.c:568 napi_alloc_skb include/linux/skbuff.h:3081 [inline] page_to_skb+0x26a/0xcf0 drivers/net/virtio_net.c:474 receive_mergeable drivers/net/virtio_net.c:1102 [inline] receive_buf+0x14db/0x58e0 drivers/net/virtio_net.c:1212 virtnet_receive drivers/net/virtio_net.c:1504 [inline] virtnet_poll+0x571/0xf40 drivers/net/virtio_net.c:1617 __napi_poll+0xc0/0x430 net/core/dev.c:7075 napi_poll net/core/dev.c:7142 [inline] net_rx_action+0x4d4/0xa10 net/core/dev.c:7232 handle_softirqs+0x339/0x830 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671 common_interrupt+0xb5/0xd0 arch/x86/kernel/irq.c:242 asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:667 Freed by task 4197: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1710 [inline] slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736 slab_free mm/slub.c:3504 [inline] kfree+0xef/0x2a0 mm/slub.c:4564 skb_free_head net/core/skbuff.c:655 [inline] skb_release_data+0x6b8/0x800 net/core/skbuff.c:677 skb_release_all net/core/skbuff.c:742 [inline] __kfree_skb+0x4c/0x60 net/core/skbuff.c:756 tcp_rcv_established+0xeb6/0x1ce0 net/ipv4/tcp_input.c:5982 tcp_v4_do_rcv+0x44b/0x9b0 net/ipv4/tcp_ipv4.c:1731 tcp_v4_rcv+0x26d8/0x2d10 net/ipv4/tcp_ipv4.c:2143 ip_protocol_deliver_rcu+0x3ad/0x770 net/ipv4/ip_input.c:204 ip_local_deliver_finish+0x1d5/0x320 net/ipv4/ip_input.c:231 NF_HOOK+0x303/0x390 include/linux/netfilter.h:302 dst_input include/net/dst.h:462 [inline] ip_sublist_rcv_finish net/ipv4/ip_input.c:577 [inline] ip_list_rcv_finish net/ipv4/ip_input.c:628 [inline] ip_sublist_rcv+0xa33/0xd30 net/ipv4/ip_input.c:636 ip_list_rcv+0x3ee/0x440 net/ipv4/ip_input.c:671 __netif_receive_skb_list_ptype net/core/dev.c:5568 [inline] __netif_receive_skb_list_core+0x57f/0x750 net/core/dev.c:5616 __netif_receive_skb_list net/core/dev.c:5668 [inline] netif_receive_skb_list_internal+0x898/0xbd0 net/core/dev.c:5759 gro_normal_list net/core/dev.c:5913 [inline] napi_complete_done+0x378/0x850 net/core/dev.c:6651 virtqueue_napi_complete drivers/net/virtio_net.c:357 [inline] virtnet_poll+0x955/0xf40 drivers/net/virtio_net.c:1624 __napi_poll+0xc0/0x430 net/core/dev.c:7075 napi_poll net/core/dev.c:7142 [inline] net_rx_action+0x4d4/0xa10 net/core/dev.c:7232 handle_softirqs+0x339/0x830 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671 common_interrupt+0xb5/0xd0 arch/x86/kernel/irq.c:242 asm_common_interrupt+0x22/0x40 arch/x86/include/asm/idtentry.h:667 Last potentially related work creation: kasan_save_stack+0x35/0x60 mm/kasan/common.c:38 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348 kvfree_call_rcu+0x105/0x7d0 kernel/rcu/tree.c:3600 drop_sysctl_table+0x359/0x4e0 fs/proc/proc_sysctl.c:1685 drop_sysctl_table+0x348/0x4e0 fs/proc/proc_sysctl.c:1688 unregister_sysctl_table+0x87/0x130 fs/proc/proc_sysctl.c:1723 neigh_sysctl_unregister+0x74/0x90 net/core/neighbour.c:3737 devinet_sysctl_unregister net/ipv4/devinet.c:2655 [inline] inetdev_destroy net/ipv4/devinet.c:326 [inline] inetdev_event+0x731/0x1370 net/ipv4/devinet.c:1611 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391 call_netdevice_notifiers_extack net/core/dev.c:2061 [inline] call_netdevice_notifiers net/core/dev.c:2075 [inline] unregister_netdevice_many+0x1049/0x19f0 net/core/dev.c:11134 unregister_netdevice_queue+0x324/0x370 net/core/dev.c:11067 unregister_netdevice include/linux/netdevice.h:3029 [inline] __tun_detach+0xd4a/0x1500 drivers/net/tun.c:686 tun_detach drivers/net/tun.c:702 [inline] tun_chr_close+0x109/0x1b0 drivers/net/tun.c:3440 __fput+0x234/0x930 fs/file_table.c:311 task_work_run+0x125/0x1a0 kernel/task_work.c:188 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0x626/0x20c0 kernel/exit.c:883 do_group_exit+0x12e/0x300 kernel/exit.c:997 get_signal+0x6ca/0x12c0 kernel/signal.c:2900 arch_do_signal_or_restart+0xe7/0x12c0 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 ret_from_fork+0x15/0x30 arch/x86/entry/entry_64.S:280 The buggy address belongs to the object at ffff88807d732400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 42 bytes inside of 512-byte region [ffff88807d732400, ffff88807d732600) The buggy address belongs to the page: page:ffffea0001f5cc00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7d730 head:ffffea0001f5cc00 order:2 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea00017ef900 0000000300000003 ffff888016c41c80 raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0x1d2a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 4367, ts 64799863916, free_ts 64798344763 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1bbd/0x1ca0 mm/page_alloc.c:4192 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5487 alloc_slab_page mm/slub.c:1780 [inline] allocate_slab mm/slub.c:1917 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1980 ___slab_alloc+0x80a/0xdd0 mm/slub.c:3013 __slab_alloc mm/slub.c:3100 [inline] slab_alloc_node mm/slub.c:3191 [inline] __kmalloc_node_track_caller+0x1fc/0x3a0 mm/slub.c:4963 kmalloc_reserve net/core/skbuff.c:356 [inline] __alloc_skb+0x22c/0x750 net/core/skbuff.c:427 alloc_skb include/linux/skbuff.h:1162 [inline] nlmsg_new include/net/netlink.h:953 [inline] __neigh_notify+0x142/0x2e0 net/core/neighbour.c:3379 neigh_cleanup_and_release+0x9d/0x250 net/core/neighbour.c:101 neigh_del net/core/neighbour.c:197 [inline] neigh_remove_one+0x4e8/0x5f0 net/core/neighbour.c:218 neigh_forced_gc net/core/neighbour.c:251 [inline] neigh_alloc net/core/neighbour.c:429 [inline] ___neigh_create+0x468/0x2250 net/core/neighbour.c:591 neigh_create include/net/neighbour.h:318 [inline] ip6_neigh_lookup+0x3b3/0x470 net/ipv6/route.c:217 ndisc_router_discovery+0xdca/0x3460 net/ipv6/ndisc.c:1343 ndisc_rcv+0x3c9/0x4e0 net/ipv6/ndisc.c:1797 icmpv6_rcv+0xf03/0x1650 net/ipv6/icmp.c:968 ip6_protocol_deliver_rcu+0x8f6/0x12c0 net/ipv6/ip6_input.c:425 ip6_input_finish+0xa2/0x130 net/ipv6/ip6_input.c:466 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317 free_unref_page+0x8f/0x2a0 mm/page_alloc.c:3396 stack_depot_save+0x418/0x440 lib/stackdepot.c:335 kasan_save_stack mm/kasan/common.c:40 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0xb3/0xd0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3225 [inline] kmem_cache_alloc_node+0x12d/0x2d0 mm/slub.c:3261 __alloc_skb+0xf4/0x750 net/core/skbuff.c:415 alloc_skb include/linux/skbuff.h:1162 [inline] nlmsg_new include/net/netlink.h:953 [inline] __neigh_notify+0x142/0x2e0 net/core/neighbour.c:3379 neigh_cleanup_and_release+0x9d/0x250 net/core/neighbour.c:101 neigh_del net/core/neighbour.c:197 [inline] neigh_remove_one+0x4e8/0x5f0 net/core/neighbour.c:218 neigh_forced_gc net/core/neighbour.c:251 [inline] neigh_alloc net/core/neighbour.c:429 [inline] ___neigh_create+0x468/0x2250 net/core/neighbour.c:591 neigh_create include/net/neighbour.h:318 [inline] ip6_neigh_lookup+0x3b3/0x470 net/ipv6/route.c:217 ndisc_router_discovery+0xdca/0x3460 net/ipv6/ndisc.c:1343 ndisc_rcv+0x3c9/0x4e0 net/ipv6/ndisc.c:1797 icmpv6_rcv+0xf03/0x1650 net/ipv6/icmp.c:968 ip6_protocol_deliver_rcu+0x8f6/0x12c0 net/ipv6/ip6_input.c:425 Memory state around the buggy address: ffff88807d732300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88807d732380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88807d732400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807d732480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807d732500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: f7 84 24 80 00 00 00 testl $0x200,0x80(%rsp) 7: 00 02 00 00 b: 43 c6 44 3d 04 f8 movb $0xf8,0x4(%r13,%r15,1) 11: 0f 85 f1 00 00 00 jne 0x108 17: 41 f7 c6 00 02 00 00 test $0x200,%r14d 1e: 74 01 je 0x21 20: fb sti 21: 48 c7 44 24 60 0e 36 movq $0x45e0360e,0x60(%rsp) 28: e0 45 * 2a: 4b c7 44 3d 00 00 00 movq $0x0,0x0(%r13,%r15,1) <-- trapping instruction 31: 00 00 33: 43 c7 44 3d 08 00 00 movl $0x0,0x8(%r13,%r15,1) 3a: 00 00 3c: 65 gs 3d: 48 rex.W 3e: 8b .byte 0x8b 3f: 04 .byte 0x4