================================================================== 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+0xe87/0x1060 kernel/locking/mutex.c:760 Read of size 8 at addr ffff888048d98b20 by task kworker/2:7/10527 CPU: 2 UID: 0 PID: 10527 Comm: kworker/2:7 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+0xe87/0x1060 kernel/locking/mutex.c:760 l2cap_chan_timeout+0x6d/0x310 net/bluetooth/l2cap_core.c:417 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Allocated by task 4744: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:417 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] l2cap_conn_add.part.0+0x60/0xa60 net/bluetooth/l2cap_core.c:6886 l2cap_conn_add include/net/bluetooth/hci_core.h:1676 [inline] l2cap_chan_connect+0x15e5/0x2020 net/bluetooth/l2cap_core.c:7077 bt_6lowpan_connect net/bluetooth/6lowpan.c:900 [inline] lowpan_control_write+0x3c9/0x740 net/bluetooth/6lowpan.c:1135 full_proxy_write+0x131/0x1a0 fs/debugfs/file.c:388 vfs_write+0x2a0/0x11d0 fs/read_write.c:684 ksys_write+0x12a/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 32087: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 __kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2539 [inline] slab_free mm/slub.c:6630 [inline] kfree+0x2b8/0x6d0 mm/slub.c:6837 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:2122 [inline] hci_conn_hash_flush+0x10e/0x260 net/bluetooth/hci_conn.c:2609 hci_dev_close_sync+0x602/0x11d0 net/bluetooth/hci_sync.c:5308 hci_dev_do_close+0x2e/0x90 net/bluetooth/hci_core.c:501 hci_unregister_dev+0x227/0x640 net/bluetooth/hci_core.c:2715 vhci_release+0x17d/0x230 drivers/bluetooth/hci_vhci.c:690 __fput+0x402/0xb70 fs/file_table.c:468 task_work_run+0x150/0x240 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x86f/0x2bf0 kernel/exit.c:966 do_group_exit+0xd3/0x2a0 kernel/exit.c:1107 get_signal+0x2671/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x7c0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x85/0x130 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x426/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888048d98800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 800 bytes inside of freed 1024-byte region [ffff888048d98800, ffff888048d98c00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888048d9f000 pfn:0x48d98 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 ffff88801b442dc0 ffffea00018dec10 ffffea0000d3aa10 raw: ffff888048d9f000 0000000000100009 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff88801b442dc0 ffffea00018dec10 ffffea0000d3aa10 head: ffff888048d9f000 0000000000100009 00000000f5000000 0000000000000000 head: 00fff00000000003 ffffea0001236601 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 0x152820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 1148, tgid 1148 (kworker/u32:8), ts 210562526065, free_ts 210424994145 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1850 prep_new_page mm/page_alloc.c:1858 [inline] get_page_from_freelist+0x10a3/0x3a30 mm/page_alloc.c:3884 __alloc_frozen_pages_noprof+0x25f/0x2470 mm/page_alloc.c:5183 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:3055 [inline] allocate_slab mm/slub.c:3228 [inline] new_slab+0x24a/0x360 mm/slub.c:3282 ___slab_alloc+0xdae/0x1a60 mm/slub.c:4651 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4770 __slab_alloc_node mm/slub.c:4846 [inline] slab_alloc_node mm/slub.c:5268 [inline] __do_kmalloc_node mm/slub.c:5641 [inline] __kmalloc_noprof+0x501/0x880 mm/slub.c:5654 kmalloc_noprof include/linux/slab.h:961 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] ieee802_11_parse_elems_full+0x1db/0x3780 net/mac80211/parse.c:1011 ieee802_11_parse_elems_crc net/mac80211/ieee80211_i.h:2470 [inline] ieee802_11_parse_elems net/mac80211/ieee80211_i.h:2477 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1569 [inline] ieee80211_ibss_rx_queued_mgmt+0xc79/0x2fe0 net/mac80211/ibss.c:1600 ieee80211_iface_process_skb net/mac80211/iface.c:1694 [inline] ieee80211_iface_work+0xe2e/0x1360 net/mac80211/iface.c:1748 cfg80211_wiphy_work+0x2c7/0x580 net/wireless/core.c:435 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 page last free pid 5999 tgid 5999 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1394 [inline] __free_frozen_pages+0x7df/0x1160 mm/page_alloc.c:2906 discard_slab mm/slub.c:3326 [inline] __put_partials+0x130/0x170 mm/slub.c:3872 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:352 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4970 [inline] slab_alloc_node mm/slub.c:5280 [inline] kmem_cache_alloc_node_noprof+0x28a/0x770 mm/slub.c:5332 __alloc_skb+0x2b2/0x380 net/core/skbuff.c:660 alloc_skb include/linux/skbuff.h:1383 [inline] mld_newpack.isra.0+0x18e/0xa20 net/ipv6/mcast.c:1775 add_grhead+0x299/0x340 net/ipv6/mcast.c:1886 add_grec+0x11b5/0x1720 net/ipv6/mcast.c:2025 mld_send_cr net/ipv6/mcast.c:2148 [inline] mld_ifc_work+0x41f/0xbf0 net/ipv6/mcast.c:2693 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff888048d98a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888048d98a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888048d98b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888048d98b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888048d98c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================