================================================================== BUG: KASAN: slab-use-after-free in rose_timer_expiry+0x45a/0x4d0 net/rose/rose_timer.c:183 Read of size 2 at addr ffff888054e8342a by task swapper/1/0 CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xcd/0x630 mm/kasan/report.c:482 kasan_report+0xe0/0x110 mm/kasan/report.c:595 rose_timer_expiry+0x45a/0x4d0 net/rose/rose_timer.c:183 call_timer_fn+0x197/0x620 kernel/time/timer.c:1747 expire_timers kernel/time/timer.c:1798 [inline] __run_timers+0x6ef/0x960 kernel/time/timer.c:2372 __run_timer_base kernel/time/timer.c:2384 [inline] __run_timer_base kernel/time/timer.c:2376 [inline] run_timer_base+0x114/0x190 kernel/time/timer.c:2393 run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2403 handle_softirqs+0x216/0x8e0 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:sched_core_balance+0xa0/0xeb0 kernel/sched/core.c:6382 Code: 12 5c 8e e8 62 38 0d 00 e8 cd 22 09 0a 41 5b 85 c0 0f 85 31 0a 00 00 4c 89 e7 e8 7b 72 fe ff e8 76 e4 38 00 fb 48 63 44 24 50 <48> c7 c3 00 13 d8 93 48 89 44 24 08 48 83 f8 07 0f 87 9c 0c 00 00 RSP: 0018:ffffc90000197b00 EFLAGS: 00000206 RAX: 0000000000000001 RBX: ffff8880b8523f10 RCX: ffffffff81c3721f RDX: 0000000000000000 RSI: ffffffff8de50330 RDI: ffffffff8c162900 RBP: ffffc90000197c20 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff90ab4c97 R11: 0000000000000000 R12: ffff8880b853a300 R13: ffff88802e042440 R14: 0000000000000000 R15: dffffc0000000000 do_balance_callbacks kernel/sched/core.c:5011 [inline] __balance_callbacks kernel/sched/core.c:5065 [inline] finish_lock_switch kernel/sched/core.c:5104 [inline] finish_task_switch.isra.0+0x472/0xc10 kernel/sched/core.c:5223 context_switch kernel/sched/core.c:5360 [inline] __schedule+0x1198/0x5de0 kernel/sched/core.c:6961 schedule_idle+0x5c/0x90 kernel/sched/core.c:7084 do_idle+0x2b6/0x510 kernel/sched/idle.c:358 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x148 Allocated by task 4575: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:388 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:405 kmalloc_noprof include/linux/slab.h:905 [inline] batadv_forw_packet_alloc+0x3ad/0x4e0 net/batman-adv/send.c:520 batadv_iv_ogm_aggregate_new+0x13c/0x4c0 net/batman-adv/bat_iv_ogm.c:571 batadv_iv_ogm_queue_add net/batman-adv/bat_iv_ogm.c:678 [inline] batadv_iv_ogm_schedule_buff+0xeb4/0x14c0 net/batman-adv/bat_iv_ogm.c:855 batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:874 [inline] batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:867 [inline] batadv_iv_send_outstanding_bat_ogm_packet+0x329/0x920 net/batman-adv/bat_iv_ogm.c:1714 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 6464: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:243 [inline] __kasan_slab_free+0x60/0x70 mm/kasan/common.c:275 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2417 [inline] slab_free mm/slub.c:4680 [inline] kfree+0x2b4/0x4d0 mm/slub.c:4879 batadv_iv_send_outstanding_bat_ogm_packet+0x26d/0x920 net/batman-adv/bat_iv_ogm.c:1720 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Last potentially related work creation: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:548 insert_work+0x36/0x230 kernel/workqueue.c:2184 __queue_work+0x3f8/0x1160 kernel/workqueue.c:2343 call_timer_fn+0x197/0x620 kernel/time/timer.c:1747 expire_timers kernel/time/timer.c:1793 [inline] __run_timers+0x569/0x960 kernel/time/timer.c:2372 __run_timer_base kernel/time/timer.c:2384 [inline] __run_timer_base kernel/time/timer.c:2376 [inline] run_timer_base+0x114/0x190 kernel/time/timer.c:2393 run_timer_softirq+0x1a/0x40 kernel/time/timer.c:2403 handle_softirqs+0x216/0x8e0 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 The buggy address belongs to the object at ffff888054e83400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 42 bytes inside of freed 512-byte region [ffff888054e83400, ffff888054e83600) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x54e80 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801b841c80 0000000000000000 dead000000000001 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b841c80 0000000000000000 dead000000000001 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea000153a001 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004 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 5843, tgid 5843 (syz-executor), ts 69001505542, free_ts 16393669077 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x132b/0x38e0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:5148 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:2487 [inline] allocate_slab mm/slub.c:2655 [inline] new_slab+0x247/0x330 mm/slub.c:2709 ___slab_alloc+0xcf2/0x1740 mm/slub.c:3891 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3981 __slab_alloc_node mm/slub.c:4056 [inline] slab_alloc_node mm/slub.c:4217 [inline] __do_kmalloc_node mm/slub.c:4364 [inline] __kmalloc_noprof+0x2f2/0x510 mm/slub.c:4377 kmalloc_noprof include/linux/slab.h:909 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] fib6_info_alloc+0x40/0x160 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x14c/0x870 net/ipv6/route.c:3811 addrconf_f6i_alloc+0x2da/0x660 net/ipv6/route.c:4680 ipv6_add_addr+0x531/0x1fe0 net/ipv6/addrconf.c:1126 addrconf_add_linklocal+0x2a5/0x500 net/ipv6/addrconf.c:3311 addrconf_addr_gen+0x364/0x3b0 net/ipv6/addrconf.c:3442 addrconf_dev_config net/ipv6/addrconf.c:3489 [inline] addrconf_init_auto_addrs+0x2ba/0x810 net/ipv6/addrconf.c:3567 addrconf_notify+0xe93/0x19e0 net/ipv6/addrconf.c:3740 page last free pid 1 tgid 1 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0x7d5/0x10f0 mm/page_alloc.c:2895 __free_pages mm/page_alloc.c:5260 [inline] free_contig_range+0x183/0x4b0 mm/page_alloc.c:7091 destroy_args+0x794/0xc10 mm/debug_vm_pgtable.c:958 debug_vm_pgtable+0x1a32/0x3640 mm/debug_vm_pgtable.c:1345 do_one_initcall+0x120/0x6e0 init/main.c:1269 do_initcall_level init/main.c:1331 [inline] do_initcalls init/main.c:1347 [inline] do_basic_setup init/main.c:1366 [inline] kernel_init_freeable+0x5c2/0x910 init/main.c:1579 kernel_init+0x1c/0x2b0 init/main.c:1469 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff888054e83300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888054e83380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888054e83400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888054e83480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888054e83500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess), 3 bytes skipped: 0: e8 62 38 0d 00 call 0xd3867 5: e8 cd 22 09 0a call 0xa0922d7 a: 41 5b pop %r11 c: 85 c0 test %eax,%eax e: 0f 85 31 0a 00 00 jne 0xa45 14: 4c 89 e7 mov %r12,%rdi 17: e8 7b 72 fe ff call 0xfffe7297 1c: e8 76 e4 38 00 call 0x38e497 21: fb sti 22: 48 63 44 24 50 movslq 0x50(%rsp),%rax * 27: 48 c7 c3 00 13 d8 93 mov $0xffffffff93d81300,%rbx <-- trapping instruction 2e: 48 89 44 24 08 mov %rax,0x8(%rsp) 33: 48 83 f8 07 cmp $0x7,%rax 37: 0f 87 9c 0c 00 00 ja 0xcd9