netlink: 4 bytes leftover after parsing attributes in process `syz.4.519'. netlink: 8 bytes leftover after parsing attributes in process `syz.4.519'. netlink: 24 bytes leftover after parsing attributes in process `syz.4.519'. comedi comedi3: c6xdigio: I/O port conflict (0x401,3) ================================================================== BUG: KASAN: slab-use-after-free in sysfs_remove_file_ns+0x3d/0x70 fs/sysfs/file.c:522 Read of size 8 at addr ffff88805d223830 by task syz.4.519/8545 CPU: 0 UID: 0 PID: 8545 Comm: syz.4.519 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xca/0x240 mm/kasan/report.c:482 kasan_report+0x118/0x150 mm/kasan/report.c:595 sysfs_remove_file_ns+0x3d/0x70 fs/sysfs/file.c:522 remove_bind_files drivers/base/bus.c:605 [inline] bus_remove_driver+0x19b/0x300 drivers/base/bus.c:743 comedi_device_detach_locked+0x178/0x750 drivers/comedi/drivers.c:207 comedi_device_detach drivers/comedi/drivers.c:215 [inline] comedi_device_attach+0x5d4/0x720 drivers/comedi/drivers.c:1011 do_devconfig_ioctl drivers/comedi/comedi_fops.c:872 [inline] comedi_unlocked_ioctl+0x605/0x1020 drivers/comedi/comedi_fops.c:2178 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa010ceeec9 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:00007fa00ef14038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fa010f46180 RCX: 00007fa010ceeec9 RDX: 0000200000000080 RSI: 0000000040946400 RDI: 000000000000000a RBP: 00007fa010d71f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa010f46218 R14: 00007fa010f46180 R15: 00007ffe9756f918 Allocated by task 5971: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:388 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:405 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x1a8/0x320 mm/slub.c:4407 kmalloc_noprof include/linux/slab.h:905 [inline] batadv_forw_packet_alloc+0x1e9/0x390 net/batman-adv/send.c:520 batadv_iv_ogm_aggregate_new net/batman-adv/bat_iv_ogm.c:571 [inline] batadv_iv_ogm_queue_add+0x845/0xd20 net/batman-adv/bat_iv_ogm.c:678 batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:855 [inline] batadv_iv_ogm_schedule+0xaf3/0xf00 net/batman-adv/bat_iv_ogm.c:874 batadv_iv_send_outstanding_bat_ogm_packet+0x6c6/0x7e0 net/batman-adv/bat_iv_ogm.c:1714 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 13: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:243 [inline] __kasan_slab_free+0x5b/0x80 mm/kasan/common.c:275 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2422 [inline] slab_free mm/slub.c:4695 [inline] kfree+0x195/0x550 mm/slub.c:4894 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 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+0x3e/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548 insert_work+0x3d/0x330 kernel/workqueue.c:2184 __queue_work+0xc3f/0x1010 kernel/workqueue.c:2343 call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747 expire_timers kernel/time/timer.c:1793 [inline] __run_timers kernel/time/timer.c:2372 [inline] __run_timer_base+0x709/0x970 kernel/time/timer.c:2384 run_timer_base kernel/time/timer.c:2393 [inline] run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403 handle_softirqs+0x22f/0x710 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] run_ktimerd+0xcf/0x190 kernel/softirq.c:1043 smpboot_thread_fn+0x53f/0xa60 kernel/smpboot.c:160 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff88805d223800 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 48 bytes inside of freed 512-byte region [ffff88805d223800, ffff88805d223a00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5d220 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x80000000000040(head|node=0|zone=1) page_type: f5(slab) raw: 0080000000000040 ffff888019841c80 ffffea0000c28600 dead000000000002 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 0080000000000040 ffff888019841c80 ffffea0000c28600 dead000000000002 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 0080000000000002 ffffea0001748801 00000000ffffffff 00000000ffffffff head: 0000000000000000 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 5842, tgid 5842 (syz-executor), ts 95588666111, free_ts 0 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x2119/0x21b0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148 alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:2492 [inline] allocate_slab+0x8a/0x370 mm/slub.c:2660 new_slab mm/slub.c:2714 [inline] ___slab_alloc+0x8d1/0xdc0 mm/slub.c:3901 __slab_alloc mm/slub.c:3992 [inline] __slab_alloc_node mm/slub.c:4067 [inline] slab_alloc_node mm/slub.c:4228 [inline] __kmalloc_cache_noprof+0xe6/0x320 mm/slub.c:4402 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] mrp_init_applicant+0x17e/0x510 net/802/mrp.c:869 register_vlan_dev+0x240/0x800 net/8021q/vlan.c:170 vlan_newlink+0x4b2/0x610 net/8021q/vlan_netlink.c:194 rtnl_newlink_create+0x30d/0xb00 net/core/rtnetlink.c:3825 __rtnl_newlink net/core/rtnetlink.c:3942 [inline] rtnl_newlink+0x16d6/0x1c70 net/core/rtnetlink.c:4057 rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6946 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x846/0xa10 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896 page_owner free stack trace missing Memory state around the buggy address: ffff88805d223700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88805d223780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88805d223800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805d223880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805d223900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================