================================================================== BUG: KASAN: slab-use-after-free in __lock_acquire+0xff/0x7c80 kernel/locking/lockdep.c:5005 Read of size 8 at addr ffff88801d65e8b8 by task syz.5.288/7516 CPU: 1 PID: 7516 Comm: syz.5.288 Not tainted 6.6.101-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 __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: 0033:0x7fb77318eb69 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:00007fb774053038 EFLAGS: 00000246 ORIG_RAX: 000000000000010e RAX: ffffffffffffffda RBX: 00007fb7733b5fa0 RCX: 00007fb77318eb69 RDX: 0000000000000000 RSI: 0000200000000280 RDI: 0000000000000040 RBP: 00007fb773211df1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000200000000180 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fb7733b5fa0 R15: 00007fff1e063678 Allocated by task 7376: 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 7519: 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 kvfree_call_rcu+0xee/0x780 kernel/rcu/tree.c:3452 inetdev_event+0x2ae/0x15c0 net/ipv4/devinet.c:1623 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 ffff88801d65e800 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 184 bytes inside of freed 256-byte region [ffff88801d65e800, ffff88801d65e900) The buggy address belongs to the physical page: page:ffffea0000759780 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1d65e head:ffffea0000759780 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 ffffea0000811780 dead000000000002 raw: 0000000000000000 0000000000100010 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5786, tgid 5786 (syz-executor), ts 86425704764, free_ts 86245935939 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_netdev_event+0x389/0x490 net/ipv4/fib_frontend.c:1500 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 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] slab_alloc mm/slub.c:3493 [inline] __kmem_cache_alloc_lru mm/slub.c:3500 [inline] kmem_cache_alloc_lru+0x115/0x2e0 mm/slub.c:3516 alloc_inode_sb include/linux/fs.h:2946 [inline] sock_alloc_inode+0x28/0xc0 net/socket.c:308 alloc_inode fs/inode.c:261 [inline] new_inode_pseudo+0x63/0x1d0 fs/inode.c:1049 sock_alloc net/socket.c:634 [inline] __sock_create+0x12d/0x940 net/socket.c:1535 sock_create net/socket.c:1627 [inline] __sys_socketpair+0x1c1/0x550 net/socket.c:1778 __do_sys_socketpair net/socket.c:1831 [inline] __se_sys_socketpair net/socket.c:1828 [inline] __x64_sys_socketpair+0x9b/0xb0 net/socket.c:1828 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 Memory state around the buggy address: ffff88801d65e780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88801d65e800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88801d65e880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801d65e900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88801d65e980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================