================================================================== BUG: KASAN: slab-use-after-free in rose_timer_expiry+0x46a/0x4b0 net/rose/rose_timer.c:183 Read of size 2 at addr ffff88805da0342a by task syz.5.1000/9708 CPU: 0 PID: 9708 Comm: syz.5.1000 Not tainted 6.6.102-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xac/0x220 mm/kasan/report.c:468 kasan_report+0x117/0x150 mm/kasan/report.c:581 rose_timer_expiry+0x46a/0x4b0 net/rose/rose_timer.c:183 call_timer_fn+0x16e/0x530 kernel/time/timer.c:1700 expire_timers kernel/time/timer.c:1751 [inline] __run_timers+0x52d/0x7d0 kernel/time/timer.c:2022 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2035 handle_softirqs+0x280/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:finish_task_switch+0x26a/0x920 kernel/sched/core.c:5254 Code: 0f 84 37 01 00 00 48 85 db 0f 85 56 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 c0 a3 1a 09 e8 ab a2 2f 00 fb 4c 8b 65 c0 <49> 8d bc 24 f8 15 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 RSP: 0000:ffffc90003857b38 EFLAGS: 00000282 RAX: 2f453788b7589f00 RBX: 0000000000000000 RCX: 2f453788b7589f00 RDX: dffffc0000000000 RSI: ffffffff8aaab9c0 RDI: ffffffff8afc66c0 RBP: ffffc90003857b90 R08: ffffffff8e4a882f R09: 1ffffffff1c95105 R10: dffffc0000000000 R11: fffffbfff1c95106 R12: ffff888062c68000 R13: dffffc0000000000 R14: ffff888022315a00 R15: 0000000000000000 context_switch kernel/sched/core.c:5383 [inline] __schedule+0x14da/0x44d0 kernel/sched/core.c:6699 preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7009 irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:694 RIP: 0010:exit_to_user_mode_loop+0x40/0x110 kernel/entry/common.c:164 Code: fb eb 1d e8 e2 d9 fa 08 65 48 8b 05 9a 36 91 7e 4c 8b 30 41 f7 c6 0e 30 02 00 0f 84 c4 00 00 00 e8 c5 6a 19 00 fb 41 f6 c6 08 <74> 05 e8 29 06 03 09 41 f7 c6 00 10 00 00 74 08 48 89 df e8 08 e6 RSP: 0000:ffffc90003857f10 EFLAGS: 00000202 RAX: 2f453788b7589f00 RBX: ffffc90003857f58 RCX: 2f453788b7589f00 RDX: dffffc0000000000 RSI: ffffffff8aaab9c0 RDI: ffffffff8afc66c0 RBP: 0000000000000000 R08: ffffffff8e4a882f R09: 1ffffffff1c95105 R10: dffffc0000000000 R11: fffffbfff1c95106 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000008 R15: ffff888062c68000 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x9/0x40 kernel/entry/common.c:315 asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:694 RIP: 0033:0x7fff2a3dc944 Code: 8d 0d 60 e7 ff ff 48 0f 45 c8 48 8b 41 20 48 85 ff 74 03 48 89 07 5d c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 f3 0f 1e fa <55> 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 ec 18 83 ff 0f 0f 87 RSP: 002b:00007fff2a3a0c78 EFLAGS: 00000202 RAX: 00007fff2a3dc940 RBX: 00007fa475fb7da0 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 00007fff2a3a0c90 RDI: 0000000000000001 RBP: 00007fa475fb7da0 R08: 0000000000000000 R09: 0000000000745d1e R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000066874 R13: 00007fa475fb6180 R14: ffffffffffffffff R15: 00007fff2a3a0dc0 Allocated by task 8048: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:383 kmalloc include/linux/slab.h:600 [inline] rose_add_node+0x23a/0xdd0 net/rose/rose_route.c:85 rose_rt_ioctl+0xa42/0xfb0 net/rose/rose_route.c:740 rose_ioctl+0x3cf/0x8b0 net/rose/af_rose.c:1380 sock_do_ioctl+0xd7/0x2f0 net/socket.c:1222 sock_ioctl+0x623/0x7a0 net/socket.c:1341 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 9663: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1806 [inline] slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1832 slab_free mm/slub.c:3816 [inline] __kmem_cache_free+0xba/0x1f0 mm/slub.c:3829 rose_rt_device_down+0x43d/0x490 net/rose/rose_route.c:515 rose_device_event+0x604/0x690 net/rose/af_rose.c:248 notifier_call_chain+0x197/0x390 kernel/notifier.c:93 call_netdevice_notifiers_extack net/core/dev.c:2064 [inline] call_netdevice_notifiers net/core/dev.c:2078 [inline] dev_close_many+0x297/0x400 net/core/dev.c:1619 dev_close+0x150/0x200 net/core/dev.c:1641 bpq_device_event+0x2f4/0x8b0 drivers/net/hamradio/bpqether.c:547 notifier_call_chain+0x197/0x390 kernel/notifier.c:93 call_netdevice_notifiers_extack net/core/dev.c:2064 [inline] call_netdevice_notifiers net/core/dev.c:2078 [inline] __dev_notify_flags+0x18e/0x2e0 net/core/dev.c:-1 dev_change_flags+0xe8/0x1a0 net/core/dev.c:8750 dev_ifsioc+0x6a7/0xe20 net/core/dev_ioctl.c:529 dev_ioctl+0x7e2/0x1170 net/core/dev_ioctl.c:786 sock_do_ioctl+0x226/0x2f0 net/socket.c:1236 sock_ioctl+0x623/0x7a0 net/socket.c:1341 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492 __call_rcu_common kernel/rcu/tree.c:2721 [inline] call_rcu+0x158/0x930 kernel/rcu/tree.c:2837 fib6_info_release include/net/ip6_fib.h:339 [inline] __ip6_del_rt+0xf1/0x150 net/ipv6/route.c:3916 ip6_del_rt+0xb4/0x100 net/ipv6/route.c:3927 __ipv6_ifa_notify+0x5be/0xaa0 net/ipv6/addrconf.c:6274 addrconf_ifdown+0xe6a/0x1880 net/ipv6/addrconf.c:3950 addrconf_notify+0x6c6/0x1010 net/ipv6/addrconf.c:-1 notifier_call_chain+0x197/0x390 kernel/notifier.c:93 call_netdevice_notifiers_extack net/core/dev.c:2064 [inline] call_netdevice_notifiers net/core/dev.c:2078 [inline] dev_close_many+0x297/0x400 net/core/dev.c:1619 unregister_netdevice_many_notify+0x4c1/0x1810 net/core/dev.c:11047 unregister_netdevice_many net/core/dev.c:11130 [inline] default_device_exit_batch+0x9cb/0xa60 net/core/dev.c:11608 ops_exit_list net/core/net_namespace.c:178 [inline] cleanup_net+0x77f/0xb90 net/core/net_namespace.c:652 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 The buggy address belongs to the object at ffff88805da03400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 42 bytes inside of freed 512-byte region [ffff88805da03400, ffff88805da03600) The buggy address belongs to the physical page: page:ffffea0001768000 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88805da00800 pfn:0x5da00 head:ffffea0001768000 order:2 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888017841c80 ffffea0000bccc10 ffffea0000bcd010 raw: ffff88805da00800 0000000000100005 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 1105, tgid 1105 (kworker/u4:7), ts 65010090893, free_ts 15798723384 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1cd/0x210 mm/page_alloc.c:1554 prep_new_page mm/page_alloc.c:1561 [inline] get_page_from_freelist+0x195c/0x19f0 mm/page_alloc.c:3191 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457 alloc_slab_page+0x5d/0x170 mm/slub.c:1876 allocate_slab mm/slub.c:2023 [inline] new_slab+0x87/0x2e0 mm/slub.c:2076 ___slab_alloc+0xc6d/0x12f0 mm/slub.c:3230 __slab_alloc mm/slub.c:3329 [inline] __slab_alloc_node mm/slub.c:3382 [inline] slab_alloc_node mm/slub.c:3475 [inline] __kmem_cache_alloc_node+0x1a2/0x260 mm/slub.c:3524 kmalloc_trace+0x2a/0xe0 mm/slab_common.c:1098 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:721 [inline] mca_alloc net/ipv6/mcast.c:880 [inline] __ipv6_dev_mc_inc+0x413/0xac0 net/ipv6/mcast.c:936 addrconf_join_solict net/ipv6/addrconf.c:2206 [inline] addrconf_dad_begin net/ipv6/addrconf.c:4067 [inline] addrconf_dad_work+0x3c5/0x14e0 net/ipv6/addrconf.c:4192 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1154 [inline] free_unref_page_prepare+0x7ce/0x8e0 mm/page_alloc.c:2336 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2429 free_contig_range+0xa1/0x160 mm/page_alloc.c:6369 destroy_args+0x87/0x770 mm/debug_vm_pgtable.c:1015 debug_vm_pgtable+0x3cc/0x410 mm/debug_vm_pgtable.c:1395 do_one_initcall+0x1fd/0x750 init/main.c:1238 do_initcall_level+0x137/0x1f0 init/main.c:1300 do_initcalls+0x69/0xd0 init/main.c:1316 kernel_init_freeable+0x3d2/0x570 init/main.c:1553 kernel_init+0x1d/0x1c0 init/main.c:1443 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Memory state around the buggy address: ffff88805da03300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88805da03380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88805da03400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805da03480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805da03500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: 0f 84 37 01 00 00 je 0x13d 6: 48 85 db test %rbx,%rbx 9: 0f 85 56 01 00 00 jne 0x165 f: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 14: 4c 8b 75 d0 mov -0x30(%rbp),%r14 18: 4c 89 e7 mov %r12,%rdi 1b: e8 c0 a3 1a 09 call 0x91aa3e0 20: e8 ab a2 2f 00 call 0x2fa2d0 25: fb sti 26: 4c 8b 65 c0 mov -0x40(%rbp),%r12 * 2a: 49 8d bc 24 f8 15 00 lea 0x15f8(%r12),%rdi <-- trapping instruction 31: 00 32: 48 89 f8 mov %rdi,%rax 35: 48 c1 e8 03 shr $0x3,%rax 39: 42 0f b6 04 28 movzbl (%rax,%r13,1),%eax 3e: 84 c0 test %al,%al