================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x3d86/0x54a0 kernel/locking/lockdep.c:4885 Read of size 8 at addr ffff88802a42c0a0 by task kworker/0:2/8809 CPU: 0 PID: 8809 Comm: kworker/0:2 Not tainted 5.14.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events l2cap_chan_timeout Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105 print_address_description.constprop.0.cold+0x6c/0x309 mm/kasan/report.c:233 __kasan_report mm/kasan/report.c:419 [inline] kasan_report.cold+0x83/0xdf mm/kasan/report.c:436 __lock_acquire+0x3d86/0x54a0 kernel/locking/lockdep.c:4885 lock_acquire kernel/locking/lockdep.c:5625 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:175 spin_lock_bh include/linux/spinlock.h:359 [inline] lock_sock_nested+0x40/0x120 net/core/sock.c:3183 l2cap_sock_teardown_cb+0xa1/0x660 net/bluetooth/l2cap_sock.c:1528 l2cap_chan_del+0xbc/0xa80 net/bluetooth/l2cap_core.c:622 l2cap_chan_close+0x1b9/0xaf0 net/bluetooth/l2cap_core.c:825 l2cap_chan_timeout+0x17e/0x2f0 net/bluetooth/l2cap_core.c:436 process_one_work+0x98d/0x1630 kernel/workqueue.c:2276 worker_thread+0x658/0x11f0 kernel/workqueue.c:2422 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Allocated by task 8873: 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:434 [inline] ____kasan_kmalloc mm/kasan/common.c:513 [inline] ____kasan_kmalloc mm/kasan/common.c:472 [inline] __kasan_kmalloc+0xa4/0xd0 mm/kasan/common.c:522 kmalloc include/linux/slab.h:596 [inline] sk_prot_alloc+0x110/0x290 net/core/sock.c:1822 sk_alloc+0x32/0xbc0 net/core/sock.c:1875 l2cap_sock_alloc.constprop.0+0x31/0x230 net/bluetooth/l2cap_sock.c:1813 l2cap_sock_create+0x123/0x1f0 net/bluetooth/l2cap_sock.c:1859 bt_sock_create+0x17c/0x340 net/bluetooth/af_bluetooth.c:130 __sock_create+0x353/0x790 net/socket.c:1464 sock_create net/socket.c:1515 [inline] __sys_socket+0xef/0x200 net/socket.c:1557 __do_sys_socket net/socket.c:1566 [inline] __se_sys_socket net/socket.c:1564 [inline] __x64_sys_socket+0x6f/0xb0 net/socket.c:1564 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 8873: 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:360 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free mm/kasan/common.c:328 [inline] __kasan_slab_free+0xff/0x130 mm/kasan/common.c:374 kasan_slab_free include/linux/kasan.h:230 [inline] slab_free_hook mm/slub.c:1628 [inline] slab_free_freelist_hook+0xe3/0x250 mm/slub.c:1653 slab_free mm/slub.c:3213 [inline] kfree+0xe4/0x540 mm/slub.c:4267 sk_prot_free net/core/sock.c:1858 [inline] __sk_destruct+0x6a8/0x900 net/core/sock.c:1943 sk_destruct+0xbd/0xe0 net/core/sock.c:1958 __sk_free+0xef/0x3d0 net/core/sock.c:1969 sk_free+0x78/0xa0 net/core/sock.c:1980 sock_put include/net/sock.h:1815 [inline] l2cap_sock_kill+0x203/0x240 net/bluetooth/l2cap_sock.c:1227 l2cap_sock_release+0x184/0x200 net/bluetooth/l2cap_sock.c:1397 __sock_release+0xcd/0x280 net/socket.c:649 sock_close+0x18/0x20 net/socket.c:1314 __fput+0x288/0x920 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:164 get_signal+0x1b35/0x2160 kernel/signal.c:2581 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:865 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:209 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:302 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff88802a42c000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 160 bytes inside of 2048-byte region [ffff88802a42c000, ffff88802a42c800) The buggy address belongs to the page: page:ffffea0000a90a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88802a428000 pfn:0x2a428 head:ffffea0000a90a00 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0000b61400 0000000200000002 ffff888010c42000 raw: ffff88802a428000 0000000080080007 00000001ffffffff 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 4875, ts 1591568059048, free_ts 1591548126169 prep_new_page mm/page_alloc.c:2436 [inline] get_page_from_freelist+0xa72/0x2f80 mm/page_alloc.c:4168 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5390 alloc_pages+0x18c/0x2a0 mm/mempolicy.c:2244 alloc_slab_page mm/slub.c:1691 [inline] allocate_slab+0x32e/0x4b0 mm/slub.c:1831 new_slab mm/slub.c:1894 [inline] new_slab_objects mm/slub.c:2640 [inline] ___slab_alloc+0x473/0x7b0 mm/slub.c:2803 __slab_alloc.constprop.0+0xa7/0xf0 mm/slub.c:2843 slab_alloc_node mm/slub.c:2925 [inline] slab_alloc mm/slub.c:2967 [inline] __kmalloc+0x312/0x330 mm/slub.c:4111 kmalloc include/linux/slab.h:596 [inline] sk_prot_alloc+0x110/0x290 net/core/sock.c:1822 sk_alloc+0x32/0xbc0 net/core/sock.c:1875 __netlink_create+0x63/0x2f0 net/netlink/af_netlink.c:640 netlink_create+0x3ad/0x5e0 net/netlink/af_netlink.c:703 __sock_create+0x353/0x790 net/socket.c:1464 sock_create net/socket.c:1515 [inline] __sys_socket+0xef/0x200 net/socket.c:1557 __do_sys_socket net/socket.c:1566 [inline] __se_sys_socket net/socket.c:1564 [inline] __x64_sys_socket+0x6f/0xb0 net/socket.c:1564 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1346 [inline] free_pcp_prepare+0x2c5/0x780 mm/page_alloc.c:1397 free_unref_page_prepare mm/page_alloc.c:3332 [inline] free_unref_page+0x19/0x690 mm/page_alloc.c:3411 qlink_free mm/kasan/quarantine.c:146 [inline] qlist_free_all+0x5a/0xc0 mm/kasan/quarantine.c:165 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:272 __kasan_slab_alloc+0x95/0xb0 mm/kasan/common.c:444 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook mm/slab.h:519 [inline] slab_alloc_node mm/slub.c:2959 [inline] slab_alloc mm/slub.c:2967 [inline] __kmalloc+0x1f4/0x330 mm/slub.c:4111 kmalloc include/linux/slab.h:596 [inline] tomoyo_realpath_from_path+0xc3/0x620 security/tomoyo/realpath.c:254 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x21b/0x400 security/tomoyo/file.c:822 security_inode_getattr+0xcf/0x140 security/security.c:1333 vfs_getattr fs/stat.c:139 [inline] vfs_statx+0x164/0x390 fs/stat.c:207 vfs_fstatat fs/stat.c:225 [inline] vfs_lstat include/linux/fs.h:3386 [inline] __do_sys_newlstat+0x91/0x110 fs/stat.c:380 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae Memory state around the buggy address: ffff88802a42bf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88802a42c000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88802a42c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802a42c100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802a42c180: fb fb fb fb fb fb fb fb 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