================================================================== BUG: KASAN: use-after-free in rose_timer_expiry+0x470/0x490 net/rose/rose_timer.c:183 Read of size 2 at addr ffff88806000b82a 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 10/02/2025 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:sched_core_balance+0x124/0xbb0 kernel/sched/core.c:6076 Code: 48 c7 c2 00 bf 0a 8a e8 9a 7c 4c 08 4c 89 74 24 18 e9 19 0a 00 00 48 8b 7c 24 20 e8 46 92 60 08 e8 e1 a0 2b 00 fb 41 83 fe 08 <0f> 83 e6 09 00 00 48 8b 44 24 40 4c 8d 24 c5 20 c8 bc 8b 4c 89 e0 RSP: 0018:ffffffff8be079e0 EFLAGS: 00000293 RAX: 79f629e6f12c2300 RBX: ffff8880b903b088 RCX: 79f629e6f12c2300 RDX: dffffc0000000000 RSI: ffffffff8a0b1c60 RDI: ffffffff8a59e580 RBP: ffffffff8be07b30 R08: dffffc0000000000 R09: ffffed1017207469 R10: ffffed1017207469 R11: 1ffff11017207468 R12: 0000000000000000 R13: dffffc0000000000 R14: 0000000000000000 R15: dffffc0000000000 do_balance_callbacks kernel/sched/core.c:4692 [inline] __balance_callbacks kernel/sched/core.c:4746 [inline] finish_lock_switch+0x17b/0x280 kernel/sched/core.c:4802 finish_task_switch+0x12f/0x640 kernel/sched/core.c:4921 context_switch kernel/sched/core.c:5052 [inline] __schedule+0x11c3/0x4390 kernel/sched/core.c:6395 schedule_idle+0x4a/0x90 kernel/sched/core.c:6506 do_idle+0x556/0x5b0 kernel/sched/idle.c:334 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403 start_kernel+0x486/0x530 init/main.c:1154 secondary_startup_64_no_verify+0xb1/0xbb Allocated by task 3560: 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:607 [inline] kzalloc include/linux/slab.h:738 [inline] kernfs_fop_open+0x3da/0xbf0 fs/kernfs/file.c:628 do_dentry_open+0x7ff/0xf80 fs/open.c:826 do_open fs/namei.c:3616 [inline] path_openat+0x2682/0x2f30 fs/namei.c:3750 do_filp_open+0x1b3/0x3e0 fs/namei.c:3777 do_sys_openat2+0x142/0x4a0 fs/open.c:1253 do_sys_open fs/open.c:1269 [inline] __do_sys_openat fs/open.c:1285 [inline] __se_sys_openat fs/open.c:1280 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1280 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 The buggy address belongs to the object at ffff88806000b800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 42 bytes inside of 512-byte region [ffff88806000b800, ffff88806000ba00) The buggy address belongs to the page: page:ffffea0001800200 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888060009400 pfn:0x60008 head:ffffea0001800200 order:2 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0000921308 ffffea000185a308 ffff888016841c80 raw: ffff888060009400 0000000000100008 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 4182, ts 63415568641, free_ts 20323961027 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:612 [inline] kzalloc include/linux/slab.h:738 [inline] fib6_info_alloc+0x2e/0xe0 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x44f/0x1210 net/ipv6/route.c:3769 ip6_route_add+0x24/0x130 net/ipv6/route.c:3865 addrconf_add_mroute net/ipv6/addrconf.c:2510 [inline] addrconf_add_dev+0x250/0x350 net/ipv6/addrconf.c:2528 addrconf_gre_config net/ipv6/addrconf.c:3455 [inline] addrconf_init_auto_addrs+0x19b/0xa80 net/ipv6/addrconf.c:3485 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 do_setlink+0xc01/0x3980 net/core/rtnetlink.c:2781 __rtnl_newlink net/core/rtnetlink.c:3452 [inline] rtnl_newlink+0x1419/0x17d0 net/core/rtnetlink.c:3574 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:1316 do_initcall_level+0x137/0x1f0 init/main.c:1389 do_initcalls+0x4b/0x90 init/main.c:1405 kernel_init_freeable+0x3ce/0x560 init/main.c:1629 kernel_init+0x19/0x1b0 init/main.c:1520 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Memory state around the buggy address: ffff88806000b700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88806000b780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88806000b800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88806000b880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88806000b900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 48 c7 c2 00 bf 0a 8a mov $0xffffffff8a0abf00,%rdx 7: e8 9a 7c 4c 08 call 0x84c7ca6 c: 4c 89 74 24 18 mov %r14,0x18(%rsp) 11: e9 19 0a 00 00 jmp 0xa2f 16: 48 8b 7c 24 20 mov 0x20(%rsp),%rdi 1b: e8 46 92 60 08 call 0x8609266 20: e8 e1 a0 2b 00 call 0x2ba106 25: fb sti 26: 41 83 fe 08 cmp $0x8,%r14d * 2a: 0f 83 e6 09 00 00 jae 0xa16 <-- trapping instruction 30: 48 8b 44 24 40 mov 0x40(%rsp),%rax 35: 4c 8d 24 c5 20 c8 bc lea -0x744337e0(,%rax,8),%r12 3c: 8b 3d: 4c 89 e0 mov %r12,%rax