================================================================== BUG: KASAN: use-after-free in __lock_acquire+0xf7/0x7c60 kernel/locking/lockdep.c:4882 Read of size 8 at addr ffff888062b3c2b8 by task syz.4.265/5183 CPU: 0 PID: 5183 Comm: syz.4.265 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: 0033:0x7f308b06bbe9 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:00007f30892d3038 EFLAGS: 00000246 ORIG_RAX: 000000000000010e RAX: ffffffffffffffda RBX: 00007f308b292fa0 RCX: 00007f308b06bbe9 RDX: 0000000000000000 RSI: 0000200000000240 RDI: 0000000000000040 RBP: 00007f308b0eee19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000200000000280 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f308b293038 R14: 00007f308b292fa0 R15: 00007ffebcab6838 Allocated by task 5037: 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 5194: 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 fib_create_info+0x196e/0x24f0 net/ipv4/fib_semantics.c:1608 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_inetaddr_event+0x13c/0x1c0 net/ipv4/fib_frontend.c:1442 notifier_call_chain kernel/notifier.c:83 [inline] blocking_notifier_call_chain+0x103/0x1b0 kernel/notifier.c:318 __inet_insert_ifa+0x9e9/0xbc0 net/ipv4/devinet.c:568 inet_insert_ifa net/ipv4/devinet.c:575 [inline] inetdev_event+0xdf6/0x1360 net/ipv4/devinet.c:1584 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 netlink_rcv_skb+0x1e0/0x430 net/netlink/af_netlink.c:2507 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x774/0x920 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x8ab/0xbc0 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] __sys_sendto+0x423/0x580 net/socket.c:2063 __do_sys_sendto net/socket.c:2075 [inline] __se_sys_sendto net/socket.c:2071 [inline] __x64_sys_sendto+0xda/0xf0 net/socket.c:2071 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 The buggy address belongs to the object at ffff888062b3c200 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 184 bytes inside of 256-byte region [ffff888062b3c200, ffff888062b3c300) The buggy address belongs to the page: page:ffffea00018acf00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888062b3ce00 pfn:0x62b3c head:ffffea00018acf00 order:1 compound_mapcount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea00018dde00 0000000500000005 ffff888016841b40 raw: ffff888062b3ce00 000000008010000a 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 4189, ts 56141753239, free_ts 11286900773 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+0x140/0x5e0 net/ipv4/fib_frontend.c:1128 fib_inetaddr_event+0x13c/0x1c0 net/ipv4/fib_frontend.c:1442 notifier_call_chain kernel/notifier.c:83 [inline] blocking_notifier_call_chain+0x103/0x1b0 kernel/notifier.c:318 __inet_insert_ifa+0x9e9/0xbc0 net/ipv4/devinet.c:568 inet_insert_ifa net/ipv4/devinet.c:575 [inline] inetdev_event+0xdf6/0x1360 net/ipv4/devinet.c:1584 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 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: ffff888062b3c180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888062b3c200: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888062b3c280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888062b3c300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888062b3c380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================