================================================================== BUG: KASAN: slab-use-after-free in __mutex_waiter_is_first kernel/locking/mutex.c:172 [inline] BUG: KASAN: slab-use-after-free in __mutex_lock_common kernel/locking/mutex.c:664 [inline] BUG: KASAN: slab-use-after-free in __mutex_lock+0x830/0x1010 kernel/locking/mutex.c:730 Read of size 8 at addr ffff888020bd6320 by task kworker/1:2/905 CPU: 1 UID: 0 PID: 905 Comm: kworker/1:2 Not tainted 6.14.0-rc2-syzkaller-00303-gad1b832bf1cf #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Workqueue: events l2cap_chan_timeout 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 __mutex_waiter_is_first kernel/locking/mutex.c:172 [inline] __mutex_lock_common kernel/locking/mutex.c:664 [inline] __mutex_lock+0x830/0x1010 kernel/locking/mutex.c:730 l2cap_chan_timeout+0x63/0x360 net/bluetooth/l2cap_core.c:417 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xac0/0x18e0 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x7ab/0x920 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Allocated by task 12613: 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:4325 kmalloc_noprof include/linux/slab.h:901 [inline] kzalloc_noprof include/linux/slab.h:1037 [inline] l2cap_conn_add+0xa9/0x8e0 net/bluetooth/l2cap_core.c:6820 l2cap_chan_connect+0x61e/0xeb0 net/bluetooth/l2cap_core.c:7011 bt_6lowpan_connect net/bluetooth/6lowpan.c:894 [inline] lowpan_control_write+0x568/0x850 net/bluetooth/6lowpan.c:1129 full_proxy_write+0x17d/0x250 fs/debugfs/file.c:398 vfs_write+0x2a1/0xd10 fs/read_write.c:677 ksys_write+0x18f/0x2b0 fs/read_write.c:731 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 12535: 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:2353 [inline] slab_free mm/slub.c:4609 [inline] kfree+0x196/0x430 mm/slub.c:4757 hci_disconn_cfm include/net/bluetooth/hci_core.h:2069 [inline] hci_conn_hash_flush+0x1c0/0x350 net/bluetooth/hci_conn.c:2698 hci_dev_close_sync+0xa8b/0x1260 net/bluetooth/hci_sync.c:5197 hci_dev_do_close net/bluetooth/hci_core.c:482 [inline] hci_unregister_dev+0x20b/0x510 net/bluetooth/hci_core.c:2677 vhci_release+0x80/0xd0 drivers/bluetooth/hci_vhci.c:664 __fput+0x3eb/0x9f0 fs/file_table.c:464 task_work_run+0x251/0x310 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xa2a/0x28e0 kernel/exit.c:938 do_group_exit+0x207/0x2c0 kernel/exit.c:1087 get_signal+0x168c/0x1720 kernel/signal.c:3036 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 The buggy address belongs to the object at ffff888020bd6000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 800 bytes inside of freed 1024-byte region [ffff888020bd6000, ffff888020bd6400) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888020bd4000 pfn:0x20bd0 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 ffff88801b041dc0 ffffea000173ea10 ffffea0000a8a810 raw: ffff888020bd4000 000000000010000f 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff88801b041dc0 ffffea000173ea10 ffffea0000a8a810 head: ffff888020bd4000 000000000010000f 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea000082f401 ffffffffffffffff 0000000000000000 head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5564, tgid 5564 (dhcpcd), ts 47184046713, free_ts 47043304133 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1551 prep_new_page mm/page_alloc.c:1559 [inline] get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3477 __alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4739 alloc_pages_mpol+0x311/0x660 mm/mempolicy.c:2270 alloc_slab_page mm/slub.c:2423 [inline] allocate_slab+0x8f/0x3a0 mm/slub.c:2587 new_slab mm/slub.c:2640 [inline] ___slab_alloc+0xc27/0x14a0 mm/slub.c:3826 __slab_alloc+0x58/0xa0 mm/slub.c:3916 __slab_alloc_node mm/slub.c:3991 [inline] slab_alloc_node mm/slub.c:4152 [inline] __do_kmalloc_node mm/slub.c:4293 [inline] __kmalloc_noprof+0x2e6/0x4c0 mm/slub.c:4306 kmalloc_noprof include/linux/slab.h:905 [inline] load_elf_phdrs+0x162/0x260 fs/binfmt_elf.c:532 load_elf_binary+0x92d/0x2820 fs/binfmt_elf.c:961 search_binary_handler fs/exec.c:1775 [inline] exec_binprm fs/exec.c:1807 [inline] bprm_execve+0x97b/0x1430 fs/exec.c:1859 do_execveat_common+0x57f/0x710 fs/exec.c:1966 do_execve fs/exec.c:2040 [inline] __do_sys_execve fs/exec.c:2116 [inline] __se_sys_execve fs/exec.c:2111 [inline] __x64_sys_execve+0x92/0xb0 fs/exec.c:2111 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 page last free pid 5558 tgid 5558 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_frozen_pages+0xe0d/0x10e0 mm/page_alloc.c:2660 discard_slab mm/slub.c:2684 [inline] __put_partials+0x160/0x1c0 mm/slub.c:3153 put_cpu_partial+0x17c/0x250 mm/slub.c:3228 __slab_free+0x290/0x380 mm/slub.c:4479 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:4115 [inline] slab_alloc_node mm/slub.c:4164 [inline] __do_kmalloc_node mm/slub.c:4293 [inline] __kmalloc_node_noprof+0x23c/0x4d0 mm/slub.c:4300 __kvmalloc_node_noprof+0x72/0x190 mm/util.c:662 seq_buf_alloc fs/seq_file.c:38 [inline] seq_read_iter+0x20c/0xd70 fs/seq_file.c:210 proc_reg_read_iter+0x1c4/0x290 fs/proc/inode.c:299 new_sync_read fs/read_write.c:484 [inline] vfs_read+0x977/0xb40 fs/read_write.c:565 ksys_read+0x18f/0x2b0 fs/read_write.c:708 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: ffff888020bd6200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888020bd6280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888020bd6300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888020bd6380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888020bd6400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================