================================================================== BUG: KASAN: slab-use-after-free in __list_del_entry_valid_or_report+0x1d4/0x200 lib/list_debug.c:62 Read of size 8 at addr ffff88805ea58558 by task syz.0.694/8928 CPU: 1 UID: 0 PID: 8928 Comm: syz.0.694 Not tainted 6.16.0-rc2-syzkaller-00269-g11313e2f7812 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xcd/0x680 mm/kasan/report.c:521 kasan_report+0xe0/0x110 mm/kasan/report.c:634 __list_del_entry_valid_or_report+0x1d4/0x200 lib/list_debug.c:62 __list_del_entry_valid include/linux/list.h:124 [inline] __list_del_entry include/linux/list.h:215 [inline] list_del_init include/linux/list.h:287 [inline] bt_accept_unlink+0x34/0x2e0 net/bluetooth/af_bluetooth.c:259 l2cap_sock_teardown_cb+0x1a3/0x3c0 net/bluetooth/l2cap_sock.c:1613 l2cap_chan_del+0xbd/0x8f0 net/bluetooth/l2cap_core.c:655 l2cap_conn_del+0x37a/0x730 net/bluetooth/l2cap_core.c:1787 l2cap_disconn_cfm net/bluetooth/l2cap_core.c:7302 [inline] l2cap_disconn_cfm+0x96/0xd0 net/bluetooth/l2cap_core.c:7295 hci_disconn_cfm include/net/bluetooth/hci_core.h:2069 [inline] hci_conn_hash_flush+0x10e/0x260 net/bluetooth/hci_conn.c:2560 hci_dev_close_sync+0x602/0x11d0 net/bluetooth/hci_sync.c:5250 hci_dev_do_close+0x2e/0x90 net/bluetooth/hci_core.c:483 hci_unregister_dev+0x213/0x620 net/bluetooth/hci_core.c:2691 vhci_release+0x79/0xf0 drivers/bluetooth/hci_vhci.c:665 __fput+0x3ff/0xb70 fs/file_table.c:465 task_work_run+0x150/0x240 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x864/0x2bd0 kernel/exit.c:955 do_group_exit+0xd3/0x2a0 kernel/exit.c:1104 get_signal+0x2673/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] irqentry_exit_to_user_mode+0x12a/0x270 kernel/entry/common.c:184 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0033:0x7f7935c67d90 Code: Unable to access opcode bytes at 0x7f7935c67d66. RSP: 002b:00007ffc25ccbec0 EFLAGS: 00000212 RAX: 00007f7935488ad0 RBX: 00007f793546d0b0 RCX: ffffffff81600f88 RDX: ffffffff81600f88 RSI: ffffffff81600f88 RDI: 00007f7935489020 RBP: 00007f793546cb60 R08: 00007f793547adb8 R09: 00007f7935fa2000 R10: 00007f79353ff008 R11: 000000000000000d R12: 00007f793546cb58 R13: 000000000000001d R14: 00007ffc25ccbfe8 R15: 00007f79353ff008 Allocated by task 8464: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4328 [inline] __kmalloc_noprof+0x223/0x510 mm/slub.c:4340 kmalloc_noprof include/linux/slab.h:909 [inline] sk_prot_alloc+0x1a8/0x2a0 net/core/sock.c:2247 sk_alloc+0x36/0xc20 net/core/sock.c:2303 bt_sock_alloc+0x3b/0x3a0 net/bluetooth/af_bluetooth.c:151 l2cap_sock_alloc.constprop.0+0x33/0x1d0 net/bluetooth/l2cap_sock.c:1891 l2cap_sock_create+0x123/0x1f0 net/bluetooth/l2cap_sock.c:1933 bt_sock_create+0x182/0x350 net/bluetooth/af_bluetooth.c:135 __sock_create+0x335/0x8d0 net/socket.c:1541 sock_create net/socket.c:1599 [inline] __sys_socket_create net/socket.c:1636 [inline] __sys_socket+0x14d/0x260 net/socket.c:1683 __do_sys_socket net/socket.c:1697 [inline] __se_sys_socket net/socket.c:1695 [inline] __x64_sys_socket+0x72/0xb0 net/socket.c:1695 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 8462: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4643 [inline] kfree+0x2b4/0x4d0 mm/slub.c:4842 sk_prot_free net/core/sock.c:2286 [inline] __sk_destruct+0x740/0x980 net/core/sock.c:2381 sk_destruct+0xc2/0xf0 net/core/sock.c:2409 __sk_free+0xf4/0x3e0 net/core/sock.c:2420 sk_free+0x6a/0x90 net/core/sock.c:2431 sock_put include/net/sock.h:1960 [inline] l2cap_sock_kill net/bluetooth/l2cap_sock.c:1265 [inline] l2cap_sock_kill+0x171/0x2d0 net/bluetooth/l2cap_sock.c:1250 l2cap_sock_release+0x189/0x210 net/bluetooth/l2cap_sock.c:1435 __sock_release+0xb0/0x270 net/socket.c:647 sock_close+0x1c/0x30 net/socket.c:1391 __fput+0x3ff/0xb70 fs/file_table.c:465 task_work_run+0x150/0x240 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xeb/0x110 kernel/entry/common.c:114 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x3f6/0x4c0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88805ea58000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1368 bytes inside of freed 2048-byte region [ffff88805ea58000, ffff88805ea58800) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88805ea5b000 pfn:0x5ea58 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000240 ffff88801b842000 ffffea00015c3610 ffffea0000dac010 raw: ffff88805ea5b000 0000000000080003 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff88801b842000 ffffea00015c3610 ffffea0000dac010 head: ffff88805ea5b000 0000000000080003 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea00017a9601 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5811, tgid 5811 (syz-executor), ts 64053826853, free_ts 50864812015 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1704 prep_new_page mm/page_alloc.c:1712 [inline] get_page_from_freelist+0x1321/0x3890 mm/page_alloc.c:3669 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:4959 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2419 alloc_slab_page mm/slub.c:2451 [inline] allocate_slab mm/slub.c:2619 [inline] new_slab+0x23b/0x330 mm/slub.c:2673 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3859 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3949 __slab_alloc_node mm/slub.c:4024 [inline] slab_alloc_node mm/slub.c:4185 [inline] __do_kmalloc_node mm/slub.c:4327 [inline] __kmalloc_node_track_caller_noprof+0x2ee/0x510 mm/slub.c:4347 kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:601 __alloc_skb+0x166/0x380 net/core/skbuff.c:670 alloc_skb include/linux/skbuff.h:1336 [inline] nlmsg_new include/net/netlink.h:1041 [inline] rtmsg_ifinfo_build_skb+0x81/0x280 net/core/rtnetlink.c:4390 rtmsg_ifinfo_event net/core/rtnetlink.c:4432 [inline] rtmsg_ifinfo_event net/core/rtnetlink.c:4422 [inline] rtmsg_ifinfo+0x9f/0x1a0 net/core/rtnetlink.c:4441 __dev_notify_flags+0x24c/0x2e0 net/core/dev.c:9493 rtnl_configure_link+0x1b5/0x280 net/core/rtnetlink.c:3589 rtnl_newlink_create net/core/rtnetlink.c:3833 [inline] __rtnl_newlink net/core/rtnetlink.c:3940 [inline] rtnl_newlink+0xcd9/0x2000 net/core/rtnetlink.c:4055 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6944 page last free pid 5697 tgid 5697 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0x7fe/0x1180 mm/page_alloc.c:2706 discard_slab mm/slub.c:2717 [inline] __put_partials+0x16d/0x1c0 mm/slub.c:3186 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4148 [inline] slab_alloc_node mm/slub.c:4197 [inline] __do_kmalloc_node mm/slub.c:4327 [inline] __kmalloc_noprof+0x1d4/0x510 mm/slub.c:4340 kmalloc_noprof include/linux/slab.h:909 [inline] tomoyo_realpath_from_path+0xc2/0x6e0 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x274/0x460 security/tomoyo/file.c:822 security_inode_getattr+0x116/0x290 security/security.c:2377 vfs_getattr fs/stat.c:259 [inline] vfs_fstat+0x4b/0xe0 fs/stat.c:281 __do_sys_newfstat+0x87/0x100 fs/stat.c:555 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff88805ea58400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805ea58480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88805ea58500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805ea58580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805ea58600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================