================================================================== BUG: KASAN: slab-use-after-free in rose_timer_expiry+0x46a/0x4b0 net/rose/rose_timer.c:183 Read of size 2 at addr ffff88805e3d882a by task syz.5.4198/22409 CPU: 0 PID: 22409 Comm: syz.5.4198 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:task_css include/linux/cgroup.h:436 [inline] RIP: 0010:blkcg_css+0xe5/0x1c0 block/blk-cgroup.c:110 Code: c7 c7 b8 9b d5 8c be ff ff ff ff e8 85 d9 62 06 89 c5 31 ff 89 c6 e8 9a 1d 7b fd 85 ed 74 07 e8 e1 19 7b fd eb 4c 49 83 c6 2c <4c> 89 f0 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 a9 00 00 00 41 8b RSP: 0018:ffffc90004017528 EFLAGS: 00000282 RAX: ffffffff840a7136 RBX: ffff88814dec6000 RCX: 0000000000000002 RDX: ffff88802a243c00 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: dffffc0000000000 R09: 1ffffffff21b46a0 R10: dffffc0000000000 R11: fffffbfff21b46a1 R12: 0000000000000cc0 R13: 0000000000000001 R14: ffff88802a243c2c R15: dffffc0000000000 blk_cgroup_congested+0xbe/0x220 block/blk-cgroup.c:2198 __folio_throttle_swaprate+0x71/0x1a0 mm/swapfile.c:3649 folio_throttle_swaprate include/linux/swap.h:638 [inline] shmem_add_to_page_cache+0x9c0/0x1b40 mm/shmem.c:794 shmem_get_folio_gfp+0xf05/0x2ac0 mm/shmem.c:2072 shmem_get_folio mm/shmem.c:2165 [inline] shmem_write_begin+0xf2/0x420 mm/shmem.c:2707 generic_perform_write+0x2fb/0x5b0 mm/filemap.c:4016 shmem_file_write_iter+0xfb/0x120 mm/shmem.c:2884 call_write_iter include/linux/fs.h:2018 [inline] aio_write+0x53c/0x790 fs/aio.c:1593 __io_submit_one fs/aio.c:-1 [inline] io_submit_one+0x70b/0x1240 fs/aio.c:2012 __do_sys_io_submit fs/aio.c:2071 [inline] __se_sys_io_submit+0x194/0x300 fs/aio.c:2041 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 RIP: 0033:0x7fbd6678ebe9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fbd676e4038 EFLAGS: 00000246 ORIG_RAX: 00000000000000d1 RAX: ffffffffffffffda RBX: 00007fbd669b5fa0 RCX: 00007fbd6678ebe9 RDX: 0000200000000780 RSI: 0000000000000001 RDI: 00007fbd676bb000 RBP: 00007fbd66811e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fbd669b6038 R14: 00007fbd669b5fa0 R15: 00007ffda03f0d88 Allocated by task 20852: 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 22131: 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_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 call_rcu_hurry include/linux/rcupdate.h:117 [inline] rcu_sync_call kernel/rcu/sync.c:47 [inline] rcu_sync_exit+0xce/0x1b0 kernel/rcu/sync.c:177 hci_uart_tty_close+0x146/0x280 drivers/bluetooth/hci_ldisc.c:547 tty_ldisc_kill+0xa3/0x1a0 drivers/tty/tty_ldisc.c:613 tty_ldisc_release+0x1a4/0x200 drivers/tty/tty_ldisc.c:781 tty_release_struct+0x2a/0xd0 drivers/tty/tty_io.c:1688 tty_release+0xc79/0x1610 drivers/tty/tty_io.c:1859 __fput+0x234/0x970 fs/file_table.c:384 task_work_run+0x1ce/0x250 kernel/task_work.c:239 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Second to 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 insert_work+0x3d/0x310 kernel/workqueue.c:1651 __queue_work+0xc39/0x1020 kernel/workqueue.c:1800 queue_work_on+0x121/0x1e0 kernel/workqueue.c:1835 queue_work include/linux/workqueue.h:562 [inline] schedule_work include/linux/workqueue.h:623 [inline] hci_uart_tx_wakeup+0x263/0x320 drivers/bluetooth/hci_ldisc.c:138 hci_uart_send_frame+0x149/0x200 drivers/bluetooth/hci_ldisc.c:292 hci_send_frame+0x1eb/0x370 net/bluetooth/hci_core.c:3031 hci_send_cmd_sync net/bluetooth/hci_core.c:4058 [inline] hci_cmd_work+0x118/0x660 net/bluetooth/hci_core.c:4087 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 ffff88805e3d8800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 42 bytes inside of freed 512-byte region [ffff88805e3d8800, ffff88805e3d8a00) The buggy address belongs to the physical page: page:ffffea000178f600 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88805e3da000 pfn:0x5e3d8 head:ffffea000178f600 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 ffffea000178ab10 ffffea0001777c10 raw: ffff88805e3da000 000000000010000e 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 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 5861, tgid 5861 (kworker/0:7), ts 90654166085, free_ts 27748745077 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 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc+0xa4/0x240 mm/slab_common.c:1020 kmalloc include/linux/slab.h:604 [inline] switchdev_deferred_enqueue+0x2d/0x240 net/switchdev/switchdev.c:117 switchdev_port_obj_add_defer net/switchdev/switchdev.c:266 [inline] switchdev_port_obj_add+0x12d/0x310 net/switchdev/switchdev.c:285 br_switchdev_mdb_notify+0x6f3/0x820 net/bridge/br_switchdev.c:666 br_mdb_notify+0x68/0x960 net/bridge/br_mdb.c:519 __br_multicast_add_group+0x6d0/0xa80 net/bridge/br_multicast.c:1546 br_multicast_add_group net/bridge/br_multicast.c:1568 [inline] br_ip6_multicast_add_group net/bridge/br_multicast.c:1620 [inline] br_ip6_multicast_mld2_report net/bridge/br_multicast.c:3036 [inline] br_multicast_ipv6_rcv net/bridge/br_multicast.c:3974 [inline] br_multicast_rcv+0x3a16/0x7030 net/bridge/br_multicast.c:4032 br_handle_frame_finish+0x785/0x1920 net/bridge/br_input.c:153 br_nf_hook_thresh+0x3b6/0x480 net/bridge/br_netfilter_hooks.c:1187 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: ffff88805e3d8700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88805e3d8780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88805e3d8800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805e3d8880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805e3d8900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ---------------- Code disassembly (best guess): 0: c7 c7 b8 9b d5 8c mov $0x8cd59bb8,%edi 6: be ff ff ff ff mov $0xffffffff,%esi b: e8 85 d9 62 06 call 0x662d995 10: 89 c5 mov %eax,%ebp 12: 31 ff xor %edi,%edi 14: 89 c6 mov %eax,%esi 16: e8 9a 1d 7b fd call 0xfd7b1db5 1b: 85 ed test %ebp,%ebp 1d: 74 07 je 0x26 1f: e8 e1 19 7b fd call 0xfd7b1a05 24: eb 4c jmp 0x72 26: 49 83 c6 2c add $0x2c,%r14 * 2a: 4c 89 f0 mov %r14,%rax <-- trapping instruction 2d: 48 c1 e8 03 shr $0x3,%rax 31: 42 0f b6 04 38 movzbl (%rax,%r15,1),%eax 36: 84 c0 test %al,%al 38: 0f 85 a9 00 00 00 jne 0xe7 3e: 41 rex.B 3f: 8b .byte 0x8b