================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x40d0/0x5570 kernel/locking/lockdep.c:4296 Read of size 8 at addr ffff8880a7c750a0 by task kworker/0:0/5 CPU: 0 PID: 5 Comm: kworker/0:0 Not tainted 5.9.0-rc3-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:77 [inline] dump_stack+0x198/0x1fd lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530 __lock_acquire+0x40d0/0x5570 kernel/locking/lockdep.c:4296 lock_acquire+0x1f3/0xae0 kernel/locking/lockdep.c:5006 __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+0x3b/0x110 net/core/sock.c:3048 l2cap_sock_teardown_cb+0x88/0x400 net/bluetooth/l2cap_sock.c:1520 l2cap_chan_close+0x2cc/0xb10 net/bluetooth/l2cap_core.c:832 l2cap_chan_timeout+0x173/0x450 net/bluetooth/l2cap_core.c:436 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Allocated by task 3908: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461 slab_post_alloc_hook mm/slab.h:518 [inline] slab_alloc mm/slab.c:3312 [inline] kmem_cache_alloc+0x13a/0x3a0 mm/slab.c:3482 getname_flags.part.0+0x50/0x4f0 fs/namei.c:138 getname_flags fs/namei.c:2646 [inline] user_path_at_empty+0xa1/0x100 fs/namei.c:2646 user_path_at include/linux/namei.h:59 [inline] vfs_statx+0x14e/0x390 fs/stat.c:202 vfs_lstat include/linux/fs.h:3178 [inline] __do_sys_newlstat+0x91/0x110 fs/stat.c:374 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 3908: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track+0x1c/0x30 mm/kasan/common.c:56 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355 __kasan_slab_free+0xd8/0x120 mm/kasan/common.c:422 __cache_free mm/slab.c:3418 [inline] kmem_cache_free.part.0+0x74/0x1e0 mm/slab.c:3693 putname+0xe1/0x120 fs/namei.c:259 filename_lookup+0x3b1/0x560 fs/namei.c:2376 user_path_at include/linux/namei.h:59 [inline] vfs_statx+0x14e/0x390 fs/stat.c:202 vfs_lstat include/linux/fs.h:3178 [inline] __do_sys_newlstat+0x91/0x110 fs/stat.c:374 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff8880a7c74c00 which belongs to the cache names_cache of size 4096 The buggy address is located 1184 bytes inside of 4096-byte region [ffff8880a7c74c00, ffff8880a7c75c00) The buggy address belongs to the page: page:00000000375ae7d8 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xa7c74 head:00000000375ae7d8 order:1 compound_mapcount:0 flags: 0xfffe0000010200(slab|head) raw: 00fffe0000010200 ffffea00024d8c08 ffffea0001d15b88 ffff8880aa241900 raw: 0000000000000000 ffff8880a7c74c00 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a7c74f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a7c75000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880a7c75080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880a7c75100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a7c75180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================