comedi comedi3: c6xdigio: I/O port conflict (0x4f2b,3) ================================================================== BUG: KASAN: slab-use-after-free in sysfs_remove_file_ns+0x3d/0x70 fs/sysfs/file.c:491 Read of size 8 at addr ffff8880776eec30 by task syz.3.2614/16412 CPU: 1 PID: 16412 Comm: syz.3.2614 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 sysfs_remove_file_ns+0x3d/0x70 fs/sysfs/file.c:491 remove_bind_files drivers/base/bus.c:602 [inline] bus_remove_driver+0x193/0x2f0 drivers/base/bus.c:740 comedi_device_detach+0x131/0x6f0 drivers/comedi/drivers.c:206 comedi_device_attach+0x561/0x660 drivers/comedi/drivers.c:1002 do_devconfig_ioctl drivers/comedi/comedi_fops.c:855 [inline] comedi_unlocked_ioctl+0x68d/0xf90 drivers/comedi/comedi_fops.c:2156 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 RIP: 0033:0x7f211558ebe9 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:00007f2116494038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f21157b6090 RCX: 00007f211558ebe9 RDX: 00002000000000c0 RSI: 0000000040946400 RDI: 0000000000000006 RBP: 00007f2115611e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f21157b6128 R14: 00007f21157b6090 R15: 00007ffca72bf088 Allocated by task 15984: 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] kzalloc include/linux/slab.h:721 [inline] bus_add_driver+0x162/0x640 drivers/base/bus.c:659 driver_register+0x23a/0x310 drivers/base/driver.c:246 c6xdigio_attach+0x94/0x880 drivers/comedi/drivers/c6xdigio.c:253 comedi_device_attach+0x519/0x660 drivers/comedi/drivers.c:998 do_devconfig_ioctl drivers/comedi/comedi_fops.c:855 [inline] comedi_unlocked_ioctl+0x68d/0xf90 drivers/comedi/comedi_fops.c:2156 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 16299: 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 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x221/0x470 lib/kobject.c:737 bus_remove_driver+0x240/0x2f0 drivers/base/bus.c:746 comedi_device_detach+0x131/0x6f0 drivers/comedi/drivers.c:206 comedi_device_attach+0x561/0x660 drivers/comedi/drivers.c:1002 do_devconfig_ioctl drivers/comedi/comedi_fops.c:855 [inline] comedi_unlocked_ioctl+0x68d/0xf90 drivers/comedi/comedi_fops.c:2156 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 free_fib_info net/ipv4/fib_semantics.c:257 [inline] fib_info_put include/net/ip_fib.h:583 [inline] fib_release_info+0x688/0x740 net/ipv4/fib_semantics.c:283 fib_table_delete+0xd80/0xf80 net/ipv4/fib_trie.c:1757 fib_magic+0x2e5/0x390 net/ipv4/fib_frontend.c:1120 fib_del_ifaddr+0x1082/0x1480 net/ipv4/fib_frontend.c:1331 fib_inetaddr_event+0xbb/0x1d0 net/ipv4/fib_frontend.c:1462 notifier_call_chain+0x197/0x390 kernel/notifier.c:93 blocking_notifier_call_chain+0x6a/0x90 kernel/notifier.c:388 __inet_del_ifa+0x876/0x1020 net/ipv4/devinet.c:447 inet_del_ifa net/ipv4/devinet.c:484 [inline] inetdev_destroy net/ipv4/devinet.c:324 [inline] inetdev_event+0x63c/0x15c0 net/ipv4/devinet.c:1637 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] unregister_netdevice_many_notify+0xf36/0x1810 net/core/dev.c:11074 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 ffff8880776eec00 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 48 bytes inside of freed 256-byte region [ffff8880776eec00, ffff8880776eed00) The buggy address belongs to the physical page: page:ffffea0001ddbb80 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880776efc00 pfn:0x776ee head:ffffea0001ddbb80 order:1 entire_mapcount:0 nr_pages_mapped:0 pincount:0 ksm flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888017841b40 ffffea0001dc7b80 dead000000000003 raw: ffff8880776efc00 000000008010000c 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5789, tgid 5789 (syz-executor), ts 76746680875, free_ts 76718577364 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] kzalloc include/linux/slab.h:721 [inline] fib_create_info+0xa61/0x2460 net/ipv4/fib_semantics.c:1459 fib_table_insert+0xc7/0x1b50 net/ipv4/fib_trie.c:1217 fib_magic+0x2c5/0x390 net/ipv4/fib_frontend.c:1118 fib_add_ifaddr+0x144/0x5e0 net/ipv4/fib_frontend.c:1140 fib_inetaddr_event+0x140/0x1d0 net/ipv4/fib_frontend.c:1454 notifier_call_chain+0x197/0x390 kernel/notifier.c:93 blocking_notifier_call_chain+0x6a/0x90 kernel/notifier.c:388 __inet_insert_ifa+0x9ae/0xbb0 net/ipv4/devinet.c:571 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 discard_slab mm/slub.c:2122 [inline] __unfreeze_partials+0x1cf/0x210 mm/slub.c:2662 put_cpu_partial+0x17c/0x250 mm/slub.c:2738 __slab_free+0x31d/0x410 mm/slub.c:3686 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767 slab_alloc_node mm/slub.c:3485 [inline] kmem_cache_alloc_node+0x150/0x330 mm/slub.c:3530 __alloc_skb+0x108/0x2c0 net/core/skbuff.c:640 alloc_skb include/linux/skbuff.h:1284 [inline] nlmsg_new include/net/netlink.h:999 [inline] inet6_netconf_notify_devconf+0x10f/0x1d0 net/ipv6/addrconf.c:582 __addrconf_sysctl_unregister net/ipv6/addrconf.c:7215 [inline] addrconf_sysctl_unregister net/ipv6/addrconf.c:7239 [inline] addrconf_notify+0x315/0x1010 net/ipv6/addrconf.c:3755 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_change_name+0x5d4/0x8a0 net/core/dev.c:1300 do_setlink+0xa15/0x3fb0 net/core/rtnetlink.c:2885 Memory state around the buggy address: ffff8880776eeb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880776eeb80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880776eec00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880776eec80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880776eed00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================