================================================================== BUG: KASAN: slab-use-after-free in __mutex_waiter_is_first kernel/locking/mutex.c:182 [inline] BUG: KASAN: slab-use-after-free in __mutex_lock_common kernel/locking/mutex.c:680 [inline] BUG: KASAN: slab-use-after-free in __mutex_lock+0x738/0xe80 kernel/locking/mutex.c:746 Read of size 8 at addr ffff8880672d6320 by task kworker/1:4/5889 CPU: 1 UID: 0 PID: 5889 Comm: kworker/1:4 Not tainted 6.15.0-syzkaller-07818-g12c331b29c73 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: events l2cap_chan_timeout Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xd2/0x2b0 mm/kasan/report.c:521 kasan_report+0x118/0x150 mm/kasan/report.c:634 __mutex_waiter_is_first kernel/locking/mutex.c:182 [inline] __mutex_lock_common kernel/locking/mutex.c:680 [inline] __mutex_lock+0x738/0xe80 kernel/locking/mutex.c:746 l2cap_chan_timeout+0x63/0x390 net/bluetooth/l2cap_core.c:417 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 9142: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4358 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] l2cap_conn_add+0xaa/0x8d0 net/bluetooth/l2cap_core.c:6863 l2cap_chan_connect+0x6c8/0xe30 net/bluetooth/l2cap_core.c:7054 l2cap_sock_connect+0x5c5/0x7a0 net/bluetooth/l2cap_sock.c:256 __sys_connect_file net/socket.c:2038 [inline] __sys_connect+0x316/0x440 net/socket.c:2057 __do_sys_connect net/socket.c:2063 [inline] __se_sys_connect net/socket.c:2060 [inline] __x64_sys_connect+0x7a/0x90 net/socket.c:2060 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5151: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2380 [inline] slab_free mm/slub.c:4642 [inline] kfree+0x18e/0x440 mm/slub.c:4841 l2cap_connect_cfm+0x11d/0x1040 net/bluetooth/l2cap_core.c:7236 hci_connect_cfm include/net/bluetooth/hci_core.h:2050 [inline] hci_conn_failed+0x1ce/0x310 net/bluetooth/hci_conn.c:1275 hci_abort_conn_sync+0x5d1/0xdf0 net/bluetooth/hci_sync.c:5620 hci_cmd_sync_work+0x213/0x3a0 net/bluetooth/hci_sync.c:332 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff8880672d6000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 800 bytes inside of freed 1024-byte region [ffff8880672d6000, ffff8880672d6400) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x672d0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801a441dc0 dead000000000100 dead000000000122 raw: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801a441dc0 dead000000000100 dead000000000122 head: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea00019cb401 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5599, tgid 5599 (dhcpcd), ts 61226246921, free_ts 61200605704 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1710 prep_new_page mm/page_alloc.c:1718 [inline] get_page_from_freelist+0x21e0/0x22c0 mm/page_alloc.c:3680 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4970 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2301 alloc_slab_page mm/slub.c:2450 [inline] allocate_slab+0x8a/0x3b0 mm/slub.c:2618 new_slab mm/slub.c:2672 [inline] ___slab_alloc+0xbfc/0x1480 mm/slub.c:3858 __slab_alloc mm/slub.c:3948 [inline] __slab_alloc_node mm/slub.c:4023 [inline] slab_alloc_node mm/slub.c:4184 [inline] __do_kmalloc_node mm/slub.c:4326 [inline] __kmalloc_noprof+0x305/0x4f0 mm/slub.c:4339 kmalloc_noprof include/linux/slab.h:909 [inline] load_elf_phdrs+0x139/0x230 fs/binfmt_elf.c:525 load_elf_binary+0x920/0x2790 fs/binfmt_elf.c:954 search_binary_handler fs/exec.c:1718 [inline] exec_binprm fs/exec.c:1750 [inline] bprm_execve+0x99c/0x1450 fs/exec.c:1802 do_execveat_common+0x510/0x6a0 fs/exec.c:1908 do_execve fs/exec.c:1982 [inline] __do_sys_execve fs/exec.c:2058 [inline] __se_sys_execve fs/exec.c:2053 [inline] __x64_sys_execve+0x94/0xb0 fs/exec.c:2053 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 5598 tgid 5598 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1254 [inline] __free_frozen_pages+0xc6e/0xe50 mm/page_alloc.c:2717 __slab_free+0x326/0x400 mm/slub.c:4553 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4147 [inline] slab_alloc_node mm/slub.c:4196 [inline] kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4203 vm_area_alloc+0x24/0x140 kernel/fork.c:441 __mmap_new_vma mm/vma.c:2403 [inline] __mmap_region mm/vma.c:2520 [inline] mmap_region+0xcf4/0x1e50 mm/vma.c:2598 do_mmap+0xc68/0x1100 mm/mmap.c:561 vm_mmap_pgoff+0x31b/0x4c0 mm/util.c:579 ksys_mmap_pgoff+0x51f/0x760 mm/mmap.c:607 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff8880672d6200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880672d6280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880672d6300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880672d6380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880672d6400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================