syzbot

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BUG: KASAN: slab-use-after-free in __lock_acquire+0xff/0x7c80 kernel/locking/lockdep.c:5005
Read of size 8 at addr ffff88802d24e4b8 by task syz.3.340/6980

CPU: 1 PID: 6980 Comm: syz.3.340 Not tainted 6.6.102-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 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
 __lock_acquire+0xff/0x7c80 kernel/locking/lockdep.c:5005
 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xa8/0xf0 kernel/locking/spinlock.c:162
 remove_wait_queue+0x24/0x120 kernel/sched/wait.c:54
 free_poll_entry fs/select.c:132 [inline]
 poll_freewait+0xb1/0x240 fs/select.c:141
 do_select+0x175b/0x1840 fs/select.c:609
 core_sys_select+0x71c/0x950 fs/select.c:678
 do_pselect fs/select.c:760 [inline]
 __do_sys_pselect6 fs/select.c:801 [inline]
 __se_sys_pselect6+0x285/0x310 fs/select.c:792
 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: 0033:0x7f5e6258ebe9
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:00007f5e633c1038 EFLAGS: 00000246 ORIG_RAX: 000000000000010e
RAX: ffffffffffffffda RBX: 00007f5e627b5fa0 RCX: 00007f5e6258ebe9
RDX: 0000000000000000 RSI: 0000200000000100 RDI: 0000000000000040
RBP: 00007f5e62611e19 R08: 0000000000000000 R09: 0000000000000000
R10: 00002000000002c0 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5e627b6038 R14: 00007f5e627b5fa0 R15: 00007fffe8db1ad8
 </TASK>

Allocated by task 6717:
 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]
 __comedi_device_postconfig_async drivers/comedi/drivers.c:666 [inline]
 __comedi_device_postconfig drivers/comedi/drivers.c:723 [inline]
 comedi_device_postconfig+0x496/0xc50 drivers/comedi/drivers.c:758
 comedi_device_attach+0x533/0x660 drivers/comedi/drivers.c:1000
 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 6984:
 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
 comedi_device_detach_cleanup drivers/comedi/drivers.c:171 [inline]
 comedi_device_detach+0x363/0x6f0 drivers/comedi/drivers.c:207
 do_devconfig_ioctl drivers/comedi/comedi_fops.c:833 [inline]
 comedi_unlocked_ioctl+0xbd0/0xf90 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_flush+0x9a7/0x11b0 net/ipv4/fib_trie.c:2076
 fib_flush net/ipv4/fib_frontend.c:195 [inline]
 fib_disable_ip+0xfd/0x170 net/ipv4/fib_frontend.c:1440
 fib_netdev_event+0x31f/0x490 net/ipv4/fib_frontend.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]
 unregister_netdevice_queue+0x324/0x360 net/core/dev.c:11010
 unregister_vlan_dev+0x342/0x4e0 net/8021q/vlan.c:118
 vlan_ioctl_handler+0x319/0x650 net/8021q/vlan.c:653
 sock_ioctl+0x524/0x7a0 net/socket.c:1305
 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

The buggy address belongs to the object at ffff88802d24e400
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 184 bytes inside of
 freed 256-byte region [ffff88802d24e400, ffff88802d24e500)

The buggy address belongs to the physical page:
page:ffffea0000b49380 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88802d24e200 pfn:0x2d24e
head:ffffea0000b49380 order:1 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000000840 ffff888017841b40 ffffea0000b01610 ffffea0000c08290
raw: ffff88802d24e200 000000000010000d 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 5786, tgid 5786 (syz-executor), ts 91711329468, free_ts 91655121218
 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+0x3fb/0x5e0 net/ipv4/fib_frontend.c:1162
 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
 __slab_free+0x35e/0x410 mm/slub.c:3722
 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+0x13e/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

Memory state around the buggy address:
 ffff88802d24e380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88802d24e400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88802d24e480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                        ^
 ffff88802d24e500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88802d24e580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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