================================================================== BUG: KASAN: slab-use-after-free in __mutex_waiter_is_first kernel/locking/mutex.c:183 [inline] BUG: KASAN: slab-use-after-free in __mutex_lock_common kernel/locking/mutex.c:678 [inline] BUG: KASAN: slab-use-after-free in __mutex_lock+0xe8a/0x1060 kernel/locking/mutex.c:760 Read of size 8 at addr ffff88805a130320 by task kworker/1:0/29 CPU: 1 UID: 0 PID: 29 Comm: kworker/1:0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Workqueue: events l2cap_chan_timeout 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:378 [inline] print_report+0xcd/0x630 mm/kasan/report.c:482 kasan_report+0xe0/0x110 mm/kasan/report.c:595 __mutex_waiter_is_first kernel/locking/mutex.c:183 [inline] __mutex_lock_common kernel/locking/mutex.c:678 [inline] __mutex_lock+0xe8a/0x1060 kernel/locking/mutex.c:760 l2cap_chan_timeout+0x6d/0x310 net/bluetooth/l2cap_core.c:417 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 9772: 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:388 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:405 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] l2cap_conn_add.part.0+0x60/0xa60 net/bluetooth/l2cap_core.c:6886 l2cap_conn_add include/net/bluetooth/hci_core.h:1651 [inline] l2cap_chan_connect+0x15e5/0x2020 net/bluetooth/l2cap_core.c:7077 l2cap_sock_connect+0x3ba/0x740 net/bluetooth/l2cap_sock.c:256 kernel_connect+0x107/0x180 net/socket.c:3656 rfcomm_session_create net/bluetooth/rfcomm/core.c:811 [inline] __rfcomm_dlc_open net/bluetooth/rfcomm/core.c:388 [inline] rfcomm_dlc_open+0x821/0xaa0 net/bluetooth/rfcomm/core.c:431 rfcomm_sock_connect+0x423/0x670 net/bluetooth/rfcomm/sock.c:409 __sys_connect_file+0x141/0x1a0 net/socket.c:2086 __sys_connect+0x13b/0x160 net/socket.c:2105 __do_sys_connect net/socket.c:2111 [inline] __se_sys_connect net/socket.c:2108 [inline] __x64_sys_connect+0x72/0xb0 net/socket.c:2108 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 9824: 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:243 [inline] __kasan_slab_free+0x60/0x70 mm/kasan/common.c:275 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2422 [inline] slab_free mm/slub.c:4695 [inline] kfree+0x2b4/0x4d0 mm/slub.c:4894 l2cap_conn_free net/bluetooth/l2cap_core.c:1811 [inline] kref_put include/linux/kref.h:65 [inline] l2cap_conn_put net/bluetooth/l2cap_core.c:1823 [inline] l2cap_conn_del+0x59c/0x730 net/bluetooth/l2cap_core.c:1803 l2cap_disconn_cfm net/bluetooth/l2cap_core.c:7325 [inline] l2cap_disconn_cfm+0x96/0xd0 net/bluetooth/l2cap_core.c:7318 hci_disconn_cfm include/net/bluetooth/hci_core.h:2097 [inline] hci_conn_hash_flush+0x10b/0x260 net/bluetooth/hci_conn.c:2599 hci_dev_do_reset net/bluetooth/hci_core.c:566 [inline] hci_dev_reset+0x249/0x610 net/bluetooth/hci_core.c:610 hci_sock_ioctl+0x493/0x7d0 net/bluetooth/hci_sock.c:1140 sock_do_ioctl+0x118/0x280 net/socket.c:1238 sock_ioctl+0x227/0x6b0 net/socket.c:1359 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl fs/ioctl.c:584 [inline] __x64_sys_ioctl+0x18b/0x210 fs/ioctl.c:584 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 The buggy address belongs to the object at ffff88805a130000 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 800 bytes inside of freed 1024-byte region [ffff88805a130000, ffff88805a130400) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5a130 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 ffff88801b842dc0 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801b842dc0 dead000000000100 dead000000000122 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0001684c01 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 9772, tgid 9771 (syz.4.1117), ts 126125723360, free_ts 125970863709 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x132b/0x38e0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:5148 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:2492 [inline] allocate_slab mm/slub.c:2660 [inline] new_slab+0x247/0x330 mm/slub.c:2714 ___slab_alloc+0xcf2/0x1750 mm/slub.c:3901 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3992 __slab_alloc_node mm/slub.c:4067 [inline] slab_alloc_node mm/slub.c:4228 [inline] __kmalloc_cache_noprof+0xfb/0x3e0 mm/slub.c:4402 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] l2cap_conn_add.part.0+0x60/0xa60 net/bluetooth/l2cap_core.c:6886 l2cap_conn_add include/net/bluetooth/hci_core.h:1651 [inline] l2cap_chan_connect+0x15e5/0x2020 net/bluetooth/l2cap_core.c:7077 l2cap_sock_connect+0x3ba/0x740 net/bluetooth/l2cap_sock.c:256 kernel_connect+0x107/0x180 net/socket.c:3656 rfcomm_session_create net/bluetooth/rfcomm/core.c:811 [inline] __rfcomm_dlc_open net/bluetooth/rfcomm/core.c:388 [inline] rfcomm_dlc_open+0x821/0xaa0 net/bluetooth/rfcomm/core.c:431 rfcomm_sock_connect+0x423/0x670 net/bluetooth/rfcomm/sock.c:409 __sys_connect_file+0x141/0x1a0 net/socket.c:2086 __sys_connect+0x13b/0x160 net/socket.c:2105 page last free pid 5976 tgid 5976 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0x7d5/0x10f0 mm/page_alloc.c:2895 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:340 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4191 [inline] slab_alloc_node mm/slub.c:4240 [inline] __do_kmalloc_node mm/slub.c:4375 [inline] __kmalloc_noprof+0x1d4/0x510 mm/slub.c:4388 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 vfs_fstatat+0xbc/0xf0 fs/stat.c:373 __do_sys_newfstatat+0x97/0x120 fs/stat.c:542 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: ffff88805a130200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805a130280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88805a130300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88805a130380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805a130400: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================