================================================================== BUG: KASAN: slab-use-after-free in hci_chan_del+0x3b/0x1b0 net/bluetooth/hci_conn.c:2853 Read of size 8 at addr ffff8880270c2a18 by task syz.3.1799/11756 CPU: 1 UID: 0 PID: 11756 Comm: syz.3.1799 Not tainted 6.14.0-rc1-next-20250206-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x169/0x550 mm/kasan/report.c:489 kasan_report+0x143/0x180 mm/kasan/report.c:602 hci_chan_del+0x3b/0x1b0 net/bluetooth/hci_conn.c:2853 l2cap_conn_free net/bluetooth/l2cap_core.c:1816 [inline] kref_put include/linux/kref.h:65 [inline] l2cap_conn_put+0x70/0xe0 net/bluetooth/l2cap_core.c:1830 l2cap_sock_shutdown+0xa8a/0x1020 net/bluetooth/l2cap_sock.c:1377 l2cap_sock_release+0x79/0x1d0 net/bluetooth/l2cap_sock.c:1416 __sock_release net/socket.c:647 [inline] sock_close+0xbc/0x240 net/socket.c:1398 __fput+0x3e9/0x9f0 fs/file_table.c:464 task_work_run+0x24f/0x310 kernel/task_work.c:227 get_signal+0x15f7/0x1750 kernel/signal.c:2809 arch_do_signal_or_restart+0x96/0x860 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:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2be8d8cde9 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:00007f2be9b2a038 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: fffffffffffffffc RBX: 00007f2be8fa5fa0 RCX: 00007f2be8d8cde9 RDX: 000000000000000e RSI: 0000200000000080 RDI: 0000000000000008 RBP: 00007f2be8e0e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f2be8fa5fa0 R15: 00007fff26b8f9e8 Allocated by task 11756: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x243/0x390 mm/slub.c:4339 kmalloc_noprof include/linux/slab.h:902 [inline] kzalloc_noprof include/linux/slab.h:1038 [inline] hci_chan_create+0xc8/0x310 net/bluetooth/hci_conn.c:2838 l2cap_conn_add+0x69/0x8e0 net/bluetooth/l2cap_core.c:6864 l2cap_chan_connect+0x623/0xeb0 net/bluetooth/l2cap_core.c:7059 l2cap_sock_connect+0x5c9/0x800 net/bluetooth/l2cap_sock.c:256 __sys_connect_file net/socket.c:2045 [inline] __sys_connect+0x288/0x2d0 net/socket.c:2064 __do_sys_connect net/socket.c:2070 [inline] __se_sys_connect net/socket.c:2067 [inline] __x64_sys_connect+0x7a/0x90 net/socket.c:2067 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5832: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2367 [inline] slab_free mm/slub.c:4623 [inline] kfree+0x196/0x430 mm/slub.c:4816 hci_chan_list_flush net/bluetooth/hci_conn.c:2878 [inline] hci_conn_cleanup net/bluetooth/hci_conn.c:149 [inline] hci_conn_del+0x4b5/0xc40 net/bluetooth/hci_conn.c:1164 hci_conn_failed+0x319/0x400 net/bluetooth/hci_conn.c:1267 hci_abort_conn_sync+0x56c/0x11f0 net/bluetooth/hci_sync.c:5588 hci_cmd_sync_work+0x22b/0x400 net/bluetooth/hci_sync.c:332 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 The buggy address belongs to the object at ffff8880270c2a00 which belongs to the cache kmalloc-128 of size 128 The buggy address is located 24 bytes inside of freed 128-byte region [ffff8880270c2a00, ffff8880270c2a80) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x270c2 anon flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801ac41a00 0000000000000000 dead000000000001 raw: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 5208, tgid 5208 (udevd), ts 34931181570, free_ts 34896461378 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1629 prep_new_page mm/page_alloc.c:1637 [inline] get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3555 __alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4817 alloc_pages_mpol+0x311/0x660 mm/mempolicy.c:2270 alloc_slab_page mm/slub.c:2437 [inline] allocate_slab+0x8f/0x3a0 mm/slub.c:2601 new_slab mm/slub.c:2654 [inline] ___slab_alloc+0xc27/0x14a0 mm/slub.c:3840 __slab_alloc+0x58/0xa0 mm/slub.c:3930 __slab_alloc_node mm/slub.c:4005 [inline] slab_alloc_node mm/slub.c:4166 [inline] __kmalloc_cache_noprof+0x27b/0x390 mm/slub.c:4334 kmalloc_noprof include/linux/slab.h:902 [inline] kzalloc_noprof include/linux/slab.h:1038 [inline] kernfs_get_open_node fs/kernfs/file.c:525 [inline] kernfs_fop_open+0x826/0xd10 fs/kernfs/file.c:700 do_dentry_open+0xdec/0x1960 fs/open.c:956 vfs_open+0x3b/0x370 fs/open.c:1086 do_open fs/namei.c:3830 [inline] path_openat+0x2c81/0x3590 fs/namei.c:3989 do_filp_open+0x27f/0x4e0 fs/namei.c:4016 do_sys_openat2+0x13d/0x1c0 fs/open.c:1428 do_sys_open fs/open.c:1443 [inline] __do_sys_openat fs/open.c:1459 [inline] __se_sys_openat fs/open.c:1454 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1454 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 page last free pid 5203 tgid 5203 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1205 [inline] free_frozen_pages+0xe0d/0x10e0 mm/page_alloc.c:2738 __slab_free+0x2c2/0x380 mm/slub.c:4534 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4129 [inline] slab_alloc_node mm/slub.c:4178 [inline] kmem_cache_alloc_noprof+0x1d9/0x380 mm/slub.c:4185 getname_flags+0xb7/0x540 fs/namei.c:139 do_sys_openat2+0xcf/0x1c0 fs/open.c:1422 do_sys_open fs/open.c:1443 [inline] __do_sys_openat fs/open.c:1459 [inline] __se_sys_openat fs/open.c:1454 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1454 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff8880270c2900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880270c2980: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8880270c2a00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880270c2a80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880270c2b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 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