================================================================== BUG: KASAN: use-after-free in __mutex_lock_common kernel/locking/mutex.c:931 [inline] BUG: KASAN: use-after-free in __mutex_lock+0x1034/0x1120 kernel/locking/mutex.c:1096 Read of size 8 at addr ffff88801a106080 by task syz-executor.0/31485 CPU: 1 PID: 31485 Comm: syz-executor.0 Not tainted 5.12.0-rc8-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x141/0x1d7 lib/dump_stack.c:120 print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:232 __kasan_report mm/kasan/report.c:399 [inline] kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:416 __mutex_lock_common kernel/locking/mutex.c:931 [inline] __mutex_lock+0x1034/0x1120 kernel/locking/mutex.c:1096 nfc_llcp_put_ssap+0x49/0x2e0 net/nfc/llcp_core.c:492 llcp_sock_release+0x1d2/0x580 net/nfc/llcp_sock.c:626 __sock_release+0xcd/0x280 net/socket.c:599 sock_close+0x18/0x20 net/socket.c:1258 __fput+0x288/0x920 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:140 exit_task_work include/linux/task_work.h:30 [inline] do_exit+0xbfc/0x2a60 kernel/exit.c:825 do_group_exit+0x125/0x310 kernel/exit.c:922 get_signal+0x47f/0x2150 kernel/signal.c:2781 arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:789 handle_signal_work kernel/entry/common.c:147 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x148/0x250 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665f9 Code: Unable to access opcode bytes at RIP 0x4665cf. RSP: 002b:00007fc68dddd218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000000 RBX: 000000000056bf68 RCX: 00000000004665f9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000056bf68 RBP: 000000000056bf60 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf6c R13: 00007fff0986484f R14: 00007fc68dddd300 R15: 0000000000022000 Allocated by task 1: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:427 [inline] ____kasan_kmalloc mm/kasan/common.c:506 [inline] ____kasan_kmalloc mm/kasan/common.c:465 [inline] __kasan_kmalloc+0x99/0xc0 mm/kasan/common.c:515 kmalloc include/linux/slab.h:554 [inline] kzalloc include/linux/slab.h:684 [inline] nfc_llcp_register_device+0x45/0x9d0 net/nfc/llcp_core.c:1572 nfc_register_device+0x6d/0x360 net/nfc/core.c:1124 nfcsim_device_new+0x345/0x5c1 drivers/nfc/nfcsim.c:408 nfcsim_init+0x71/0x14d drivers/nfc/nfcsim.c:455 do_one_initcall+0x103/0x650 init/main.c:1226 do_initcall_level init/main.c:1299 [inline] do_initcalls init/main.c:1315 [inline] do_basic_setup init/main.c:1335 [inline] kernel_init_freeable+0x63e/0x6c2 init/main.c:1537 kernel_init+0xd/0x1b8 init/main.c:1424 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Freed by task 31485: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:357 ____kasan_slab_free mm/kasan/common.c:360 [inline] ____kasan_slab_free mm/kasan/common.c:325 [inline] __kasan_slab_free+0xf5/0x130 mm/kasan/common.c:367 kasan_slab_free include/linux/kasan.h:199 [inline] slab_free_hook mm/slub.c:1562 [inline] slab_free_freelist_hook+0x92/0x210 mm/slub.c:1600 slab_free mm/slub.c:3161 [inline] kfree+0xe5/0x7f0 mm/slub.c:4213 local_release net/nfc/llcp_core.c:175 [inline] kref_put include/linux/kref.h:65 [inline] nfc_llcp_local_put net/nfc/llcp_core.c:183 [inline] nfc_llcp_local_put+0x194/0x200 net/nfc/llcp_core.c:178 llcp_sock_destruct+0x81/0x150 net/nfc/llcp_sock.c:950 __sk_destruct+0x4b/0x900 net/core/sock.c:1795 sk_destruct+0xbd/0xe0 net/core/sock.c:1839 __sk_free+0xef/0x3d0 net/core/sock.c:1850 sk_free+0x78/0xa0 net/core/sock.c:1861 sock_put include/net/sock.h:1807 [inline] llcp_sock_release+0x3c9/0x580 net/nfc/llcp_sock.c:644 __sock_release+0xcd/0x280 net/socket.c:599 sock_close+0x18/0x20 net/socket.c:1258 __fput+0x288/0x920 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:140 exit_task_work include/linux/task_work.h:30 [inline] do_exit+0xbfc/0x2a60 kernel/exit.c:825 do_group_exit+0x125/0x310 kernel/exit.c:922 get_signal+0x47f/0x2150 kernel/signal.c:2781 arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:789 handle_signal_work kernel/entry/common.c:147 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x148/0x250 kernel/entry/common.c:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff88801a106000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 128 bytes inside of 2048-byte region [ffff88801a106000, ffff88801a106800) The buggy address belongs to the page: page:ffffea0000684000 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1a100 head:ffffea0000684000 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head) raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888010442000 raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88801a105f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88801a106000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88801a106080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88801a106100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801a106180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================