================================================================== BUG: KASAN: use-after-free in __lock_acquire+0xf7/0x7c50 kernel/locking/lockdep.c:4919 Read of size 8 at addr ffff888018468eb8 by task syz.6.4291/22214 CPU: 0 PID: 22214 Comm: syz.6.4291 Not tainted 6.1.147-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0xa8/0x200 mm/kasan/report.c:418 kasan_report+0x10b/0x140 mm/kasan/report.c:522 __lock_acquire+0xf7/0x7c50 kernel/locking/lockdep.c:4919 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162 remove_wait_queue+0x20/0x120 kernel/sched/wait.c:54 free_poll_entry fs/select.c:132 [inline] poll_freewait+0x99/0x210 fs/select.c:141 do_select+0x1761/0x1850 fs/select.c:609 core_sys_select+0x6ad/0x8b0 fs/select.c:678 do_pselect fs/select.c:760 [inline] __do_sys_pselect6 fs/select.c:801 [inline] __se_sys_pselect6+0x2ed/0x3a0 fs/select.c:792 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f4a94f8eb69 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:00007f4a95d8a038 EFLAGS: 00000246 ORIG_RAX: 000000000000010e RAX: ffffffffffffffda RBX: 00007f4a951b6080 RCX: 00007f4a94f8eb69 RDX: 0000000000000000 RSI: 0000200000000280 RDI: 0000000000000040 RBP: 00007f4a95011df1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000200000000180 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f4a951b6080 R15: 00007ffc69959678 Allocated by task 22077: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:383 kmalloc include/linux/slab.h:563 [inline] kzalloc include/linux/slab.h:699 [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+0x52f/0x650 drivers/comedi/drivers.c:1000 do_devconfig_ioctl drivers/comedi/comedi_fops.c:851 [inline] comedi_unlocked_ioctl+0x5ec/0xf20 drivers/comedi/comedi_fops.c:2151 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 22215: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x2d/0x50 mm/kasan/generic.c:516 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1724 [inline] slab_free_freelist_hook+0x131/0x1a0 mm/slub.c:1750 slab_free mm/slub.c:3661 [inline] __kmem_cache_free+0xb6/0x1f0 mm/slub.c:3674 comedi_device_detach_cleanup drivers/comedi/drivers.c:171 [inline] comedi_device_detach+0x35f/0x6e0 drivers/comedi/drivers.c:207 do_devconfig_ioctl drivers/comedi/comedi_fops.c:829 [inline] comedi_unlocked_ioctl+0xb6b/0xf20 drivers/comedi/comedi_fops.c:2151 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb2/0xc0 mm/kasan/generic.c:486 kvfree_call_rcu+0x108/0x870 kernel/rcu/tree.c:3405 drop_sysctl_table+0x2fa/0x430 fs/proc/proc_sysctl.c:1731 drop_sysctl_table+0x2e9/0x430 fs/proc/proc_sysctl.c:1734 unregister_sysctl_table+0x85/0x130 fs/proc/proc_sysctl.c:1769 neigh_sysctl_unregister+0x74/0x90 net/core/neighbour.c:3871 addrconf_sysctl_unregister net/ipv6/addrconf.c:7208 [inline] addrconf_ifdown+0x1711/0x1a10 net/ipv6/addrconf.c:3952 addrconf_notify+0x405/0xf40 net/ipv6/addrconf.c:-1 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:455 call_netdevice_notifiers_extack net/core/dev.c:2039 [inline] call_netdevice_notifiers net/core/dev.c:2053 [inline] unregister_netdevice_many+0xfdc/0x1840 net/core/dev.c:10978 default_device_exit_batch+0x9c3/0xa50 net/core/dev.c:11491 ops_exit_list net/core/net_namespace.c:177 [inline] cleanup_net+0x77b/0xb80 net/core/net_namespace.c:640 process_one_work+0x898/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Second to last potentially related work creation: kasan_save_stack+0x3a/0x60 mm/kasan/common.c:45 __kasan_record_aux_stack+0xb2/0xc0 mm/kasan/generic.c:486 kvfree_call_rcu+0x108/0x870 kernel/rcu/tree.c:3405 drop_sysctl_table+0x2fa/0x430 fs/proc/proc_sysctl.c:1731 drop_sysctl_table+0x2e9/0x430 fs/proc/proc_sysctl.c:1734 unregister_sysctl_table+0x85/0x130 fs/proc/proc_sysctl.c:1769 __devinet_sysctl_unregister net/ipv4/devinet.c:2636 [inline] devinet_sysctl_unregister net/ipv4/devinet.c:2664 [inline] inetdev_destroy net/ipv4/devinet.c:329 [inline] inetdev_event+0x6db/0x1410 net/ipv4/devinet.c:1616 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:455 call_netdevice_notifiers_extack net/core/dev.c:2039 [inline] call_netdevice_notifiers net/core/dev.c:2053 [inline] unregister_netdevice_many+0xfdc/0x1840 net/core/dev.c:10978 ip_tunnel_delete_nets+0x318/0x360 net/ipv4/ip_tunnel.c:1171 ops_exit_list net/core/net_namespace.c:177 [inline] cleanup_net+0x77b/0xb80 net/core/net_namespace.c:640 process_one_work+0x898/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 The buggy address belongs to the object at ffff888018468e00 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 184 bytes inside of 256-byte region [ffff888018468e00, ffff888018468f00) The buggy address belongs to the physical page: page:ffffea0000611a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x18468 head:ffffea0000611a00 order:1 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea000063ac00 dead000000000002 ffff888017441b40 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 2459303555, free_ts 0 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2532 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x1a26/0x1ac0 mm/page_alloc.c:4328 __alloc_pages+0x1df/0x4e0 mm/page_alloc.c:5614 alloc_page_interleave+0x24/0x1e0 mm/mempolicy.c:2115 alloc_slab_page+0x5d/0x160 mm/slub.c:1794 allocate_slab mm/slub.c:1939 [inline] new_slab+0x87/0x2c0 mm/slub.c:1992 ___slab_alloc+0xbc6/0x1220 mm/slub.c:3180 __slab_alloc mm/slub.c:3279 [inline] slab_alloc_node mm/slub.c:3364 [inline] __kmem_cache_alloc_node+0x1a0/0x260 mm/slub.c:3437 __do_kmalloc_node mm/slab_common.c:935 [inline] __kmalloc_node_track_caller+0x9e/0x230 mm/slab_common.c:956 __do_krealloc mm/slab_common.c:1336 [inline] krealloc+0x6a/0x100 mm/slab_common.c:1369 add_sysfs_param+0xe8/0x930 kernel/params.c:651 kernel_add_sysfs_param+0xaf/0x11b kernel/params.c:812 param_sysfs_builtin+0x1f6/0x27c kernel/params.c:851 param_sysfs_init+0x66/0x6a kernel/params.c:972 do_one_initcall+0x214/0x7a0 init/main.c:1298 do_initcall_level+0x137/0x1e4 init/main.c:1371 page_owner free stack trace missing Memory state around the buggy address: ffff888018468d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888018468e00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888018468e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888018468f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888018468f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================