================================================================== BUG: KASAN: use-after-free in __lock_acquire+0xf7/0x7c60 kernel/locking/lockdep.c:4882 Read of size 8 at addr ffff888060e7a4b8 by task syz.4.1739/11405 CPU: 0 PID: 11405 Comm: syz.4.1739 Not tainted 5.15.189-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 print_address_description+0x60/0x2d0 mm/kasan/report.c:248 __kasan_report mm/kasan/report.c:434 [inline] kasan_report+0xdf/0x130 mm/kasan/report.c:451 __lock_acquire+0xf7/0x7c60 kernel/locking/lockdep.c:4882 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 __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:55 free_poll_entry fs/select.c:134 [inline] poll_freewait+0x99/0x210 fs/select.c:143 do_select+0x1629/0x16f0 fs/select.c:611 core_sys_select+0x65c/0x860 fs/select.c:680 do_pselect fs/select.c:762 [inline] __do_sys_pselect6 fs/select.c:803 [inline] __se_sys_pselect6+0x2ed/0x3a0 fs/select.c:794 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fc400278b69 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:00007fc3fe0bf038 EFLAGS: 00000246 ORIG_RAX: 000000000000010e RAX: ffffffffffffffda RBX: 00007fc4004a0080 RCX: 00007fc400278b69 RDX: 0000000000000000 RSI: 0000200000000280 RDI: 0000000000000040 RBP: 00007fc4002fbdf1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000200000000180 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fc4004a0080 R15: 00007fffab657478 Allocated by task 11343: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] __kasan_kmalloc+0xb5/0xf0 mm/kasan/common.c:522 kmalloc include/linux/slab.h:604 [inline] kzalloc include/linux/slab.h:735 [inline] __comedi_device_postconfig_async drivers/comedi/drivers.c:664 [inline] __comedi_device_postconfig drivers/comedi/drivers.c:721 [inline] comedi_device_postconfig+0x496/0xc50 drivers/comedi/drivers.c:756 comedi_device_attach+0x52f/0x650 drivers/comedi/drivers.c:998 do_devconfig_ioctl drivers/comedi/comedi_fops.c:851 [inline] comedi_unlocked_ioctl+0x5ec/0xe90 drivers/comedi/comedi_fops.c:2131 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Freed by task 11406: kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:46 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1705 [inline] slab_free_freelist_hook+0xea/0x170 mm/slub.c:1731 slab_free mm/slub.c:3499 [inline] kfree+0xef/0x2a0 mm/slub.c:4559 comedi_device_detach_cleanup drivers/comedi/drivers.c:172 [inline] comedi_device_detach+0x35f/0x6e0 drivers/comedi/drivers.c:208 do_devconfig_ioctl drivers/comedi/comedi_fops.c:829 [inline] comedi_unlocked_ioctl+0xbd0/0xe90 drivers/comedi/comedi_fops.c:2131 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 Last potentially related work creation: kasan_save_stack+0x35/0x60 mm/kasan/common.c:38 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348 __call_rcu kernel/rcu/tree.c:3011 [inline] call_rcu+0x182/0x930 kernel/rcu/tree.c:3091 free_fib_info net/ipv4/fib_semantics.c:255 [inline] fib_info_put include/net/ip_fib.h:579 [inline] fib_release_info+0x684/0x740 net/ipv4/fib_semantics.c:281 fib_table_delete+0xd61/0xf60 net/ipv4/fib_trie.c:1747 fib_magic+0x2e1/0x390 net/ipv4/fib_frontend.c:1108 fib_del_ifaddr+0x1045/0x1440 net/ipv4/fib_frontend.c:1319 fib_inetaddr_event+0xb7/0x1c0 net/ipv4/fib_frontend.c:1450 notifier_call_chain kernel/notifier.c:83 [inline] blocking_notifier_call_chain+0x103/0x1b0 kernel/notifier.c:318 __inet_del_ifa+0x879/0x1020 net/ipv4/devinet.c:443 inet_del_ifa net/ipv4/devinet.c:480 [inline] inetdev_destroy net/ipv4/devinet.c:320 [inline] inetdev_event+0x5d3/0x1360 net/ipv4/devinet.c:1612 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391 call_netdevice_notifiers_extack net/core/dev.c:2061 [inline] call_netdevice_notifiers net/core/dev.c:2075 [inline] unregister_netdevice_many+0xf57/0x18f0 net/core/dev.c:11134 vti6_exit_batch_net+0x3c6/0x410 net/ipv6/ip6_vti.c:1190 ops_exit_list net/core/net_namespace.c:177 [inline] cleanup_net+0x77b/0xb80 net/core/net_namespace.c:635 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 The buggy address belongs to the object at ffff888060e7a400 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 184 bytes inside of 256-byte region [ffff888060e7a400, ffff888060e7a500) The buggy address belongs to the page: page:ffffea0001839e80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x60e7a head:ffffea0001839e80 order:1 compound_mapcount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea00017f0880 0000000b0000000b ffff888016841b40 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 4183, ts 55879773462, free_ts 11873185035 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5474 alloc_slab_page mm/slub.c:1775 [inline] allocate_slab mm/slub.c:1912 [inline] new_slab+0xc0/0x4b0 mm/slub.c:1975 ___slab_alloc+0x81e/0xdf0 mm/slub.c:3008 __slab_alloc mm/slub.c:3095 [inline] slab_alloc_node mm/slub.c:3186 [inline] slab_alloc mm/slub.c:3228 [inline] __kmalloc+0x1cd/0x330 mm/slub.c:4403 kmalloc include/linux/slab.h:609 [inline] kzalloc include/linux/slab.h:735 [inline] fib_create_info+0xabc/0x24f0 net/ipv4/fib_semantics.c:1478 fib_table_insert+0xe4/0x1b20 net/ipv4/fib_trie.c:1212 fib_magic+0x2c1/0x390 net/ipv4/fib_frontend.c:1106 fib_add_ifaddr+0x389/0x5e0 net/ipv4/fib_frontend.c:1143 fib_netdev_event+0x35c/0x480 net/ipv4/fib_frontend.c:1488 notifier_call_chain kernel/notifier.c:83 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391 call_netdevice_notifiers_extack net/core/dev.c:2061 [inline] call_netdevice_notifiers net/core/dev.c:2075 [inline] __dev_notify_flags+0x178/0x2d0 net/core/dev.c:-1 dev_change_flags+0xe3/0x1a0 net/core/dev.c:8929 do_setlink+0xc01/0x3980 net/core/rtnetlink.c:2779 __rtnl_newlink net/core/rtnetlink.c:3450 [inline] rtnl_newlink+0x1419/0x17d0 net/core/rtnetlink.c:3572 rtnetlink_rcv_msg+0x9b9/0xe60 net/core/rtnetlink.c:5650 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1340 [inline] free_pcp_prepare mm/page_alloc.c:1391 [inline] free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317 free_unref_page+0x94/0x280 mm/page_alloc.c:3396 free_contig_range+0x96/0xf0 mm/page_alloc.c:9393 destroy_args+0xef/0x8b0 mm/debug_vm_pgtable.c:1018 debug_vm_pgtable+0x318/0x370 mm/debug_vm_pgtable.c:1331 do_one_initcall+0x1ee/0x680 init/main.c:1302 do_initcall_level+0x137/0x1f0 init/main.c:1375 do_initcalls+0x4b/0x90 init/main.c:1391 kernel_init_freeable+0x3ce/0x560 init/main.c:1615 kernel_init+0x19/0x1b0 init/main.c:1506 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Memory state around the buggy address: ffff888060e7a380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888060e7a400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888060e7a480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888060e7a500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888060e7a580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================