================================================================== BUG: KASAN: use-after-free in rose_timer_expiry+0x470/0x490 net/rose/rose_timer.c:183 Read of size 2 at addr ffff88805ff6e82a by task swapper/0/0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x168/0x230 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+0x16c/0x530 kernel/time/timer.c:1451 expire_timers kernel/time/timer.c:1496 [inline] __run_timers+0x525/0x7c0 kernel/time/timer.c:1767 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780 handle_softirqs+0x328/0x820 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x12f/0x220 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:default_idle+0xb/0x10 arch/x86/kernel/process.c:730 Code: bf 48 89 df e8 86 f5 09 f8 eb b5 e8 3f b0 f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 00 cc 66 90 0f 00 2d f7 83 53 00 fb f4 0f 1f 40 00 41 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 48 RSP: 0018:ffffffff8be07dc8 EFLAGS: 000002c6 RAX: 9bf3d71b8da0c000 RBX: ffffffff8bebc3c0 RCX: 9bf3d71b8da0c000 RDX: 0000000000000001 RSI: ffffffff8a0b1820 RDI: ffffffff8a59a480 RBP: ffffffff8be07ef8 R08: dffffc0000000000 R09: ffffed1017207662 R10: ffffed1017207662 R11: 1ffff11017207661 R12: ffffffff8d6991e8 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff17d7878 default_idle_call+0x81/0xc0 kernel/sched/idle.c:112 cpuidle_idle_call kernel/sched/idle.c:194 [inline] do_idle+0x21b/0x5b0 kernel/sched/idle.c:306 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403 start_kernel+0x486/0x530 init/main.c:1140 secondary_startup_64_no_verify+0xb1/0xbb Allocated by task 4320: 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 include/linux/slab.h:604 [inline] batadv_forw_packet_alloc+0x1e5/0x380 net/batman-adv/send.c:519 batadv_iv_ogm_aggregate_new net/batman-adv/bat_iv_ogm.c:562 [inline] batadv_iv_ogm_queue_add+0x77b/0xcf0 net/batman-adv/bat_iv_ogm.c:670 batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:833 [inline] batadv_iv_ogm_schedule+0x81c/0xe90 net/batman-adv/bat_iv_ogm.c:868 batadv_iv_send_outstanding_bat_ogm_packet+0x72d/0x840 net/batman-adv/bat_iv_ogm.c:1712 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 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 insert_work+0x54/0x3d0 kernel/workqueue.c:1366 __queue_work+0x9c5/0xd50 kernel/workqueue.c:1532 call_timer_fn+0x16c/0x530 kernel/time/timer.c:1451 expire_timers kernel/time/timer.c:1491 [inline] __run_timers+0x550/0x7c0 kernel/time/timer.c:1767 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780 handle_softirqs+0x328/0x820 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x12f/0x220 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 The buggy address belongs to the object at ffff88805ff6e800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 42 bytes inside of 512-byte region [ffff88805ff6e800, ffff88805ff6ea00) The buggy address belongs to the page: page:ffffea00017fdb00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88805ff6e800 pfn:0x5ff6c head:ffffea00017fdb00 order:2 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001893508 ffffea00017e5508 ffff888016841c80 raw: ffff88805ff6e800 0000000000100003 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4183, ts 74461834340, free_ts 27767358086 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192 __alloc_pages+0x1e1/0x470 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+0x81e/0xdf0 mm/slub.c:3013 __slab_alloc mm/slub.c:3100 [inline] slab_alloc_node mm/slub.c:3191 [inline] slab_alloc mm/slub.c:3233 [inline] __kmalloc+0x1cd/0x330 mm/slub.c:4408 kmalloc include/linux/slab.h:609 [inline] kzalloc include/linux/slab.h:735 [inline] fib6_info_alloc+0x2e/0xe0 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x44f/0x1210 net/ipv6/route.c:3769 addrconf_f6i_alloc+0x1b9/0x3f0 net/ipv6/route.c:4592 ipv6_add_addr+0x438/0xde0 net/ipv6/addrconf.c:1123 add_addr+0x83/0x2c0 net/ipv6/addrconf.c:3130 add_v4_addrs+0x6f9/0xbf0 net/ipv6/addrconf.c:3192 addrconf_sit_config net/ipv6/addrconf.c:3441 [inline] addrconf_init_auto_addrs+0x37d/0xa80 net/ipv6/addrconf.c:3479 addrconf_notify+0xa6b/0xf00 net/ipv6/addrconf.c:3662 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] __dev_notify_flags+0x178/0x2d0 net/core/dev.c:-1 dev_change_flags+0xe3/0x1a0 net/core/dev.c:8929 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+0x94/0x280 mm/page_alloc.c:3396 free_contig_range+0x96/0xf0 mm/page_alloc.c:9406 destroy_args+0x100/0xa20 mm/debug_vm_pgtable.c:1018 debug_vm_pgtable+0x318/0x370 mm/debug_vm_pgtable.c:1336 do_one_initcall+0x1ee/0x680 init/main.c:1302 do_initcall_level+0x137/0x1f0 init/main.c:1375 do_initcalls+0x4b/0x90 init/main.c:1391 kernel_init_freeable+0x3ce/0x560 init/main.c:1615 kernel_init+0x19/0x1b0 init/main.c:1506 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Memory state around the buggy address: ffff88805ff6e700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88805ff6e780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88805ff6e800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805ff6e880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805ff6e900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== vkms_vblank_simulate: vblank timer overrun ---------------- Code disassembly (best guess): 0: bf 48 89 df e8 mov $0xe8df8948,%edi 5: 86 f5 xchg %dh,%ch 7: 09 f8 or %edi,%eax 9: eb b5 jmp 0xffffffc0 b: e8 3f b0 f6 ff call 0xfff6b04f 10: 00 00 add %al,(%rax) 12: cc int3 13: cc int3 14: 00 00 add %al,(%rax) 16: cc int3 17: cc int3 18: 00 00 add %al,(%rax) 1a: cc int3 1b: cc int3 1c: 00 00 add %al,(%rax) 1e: cc int3 1f: 66 90 xchg %ax,%ax 21: 0f 00 2d f7 83 53 00 verw 0x5383f7(%rip) # 0x53841f 28: fb sti 29: f4 hlt * 2a: c3 ret <-- trapping instruction 2b: 0f 1f 40 00 nopl 0x0(%rax) 2f: 41 57 push %r15 31: 41 56 push %r14 33: 53 push %rbx 34: 49 be 00 00 00 00 00 movabs $0xdffffc0000000000,%r14 3b: fc ff df 3e: 65 gs 3f: 48 rex.W