================================================================== BUG: KASAN: use-after-free in l2cap_chan_close+0x46/0xae0 net/bluetooth/l2cap_core.c:790 Read of size 8 at addr ffff888097a17000 by task kworker/1:3/2716 CPU: 1 PID: 2716 Comm: kworker/1:3 Not tainted 5.8.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events do_enable_set Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1f0/0x31e lib/dump_stack.c:118 print_address_description+0x66/0x5a0 mm/kasan/report.c:383 __kasan_report mm/kasan/report.c:513 [inline] kasan_report+0x132/0x1d0 mm/kasan/report.c:530 l2cap_chan_close+0x46/0xae0 net/bluetooth/l2cap_core.c:790 do_enable_set+0x662/0x900 net/bluetooth/6lowpan.c:1082 process_one_work+0x789/0xfc0 kernel/workqueue.c:2269 worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415 kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 Allocated by task 2716: save_stack mm/kasan/common.c:48 [inline] set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc+0x103/0x140 mm/kasan/common.c:494 kmem_cache_alloc_trace+0x234/0x300 mm/slab.c:3551 kmalloc include/linux/slab.h:555 [inline] kzalloc include/linux/slab.h:669 [inline] l2cap_chan_create+0x4c/0x320 net/bluetooth/l2cap_core.c:450 chan_create net/bluetooth/6lowpan.c:648 [inline] bt_6lowpan_listen net/bluetooth/6lowpan.c:967 [inline] do_enable_set+0x6a7/0x900 net/bluetooth/6lowpan.c:1086 process_one_work+0x789/0xfc0 kernel/workqueue.c:2269 worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415 kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 Freed by task 3792: save_stack mm/kasan/common.c:48 [inline] set_track mm/kasan/common.c:56 [inline] kasan_set_free_info mm/kasan/common.c:316 [inline] __kasan_slab_free+0x114/0x170 mm/kasan/common.c:455 __cache_free mm/slab.c:3426 [inline] kfree+0x10a/0x220 mm/slab.c:3757 do_enable_set+0x66e/0x900 net/bluetooth/6lowpan.c:1083 process_one_work+0x789/0xfc0 kernel/workqueue.c:2269 worker_thread+0xaa4/0x1460 kernel/workqueue.c:2415 kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 The buggy address belongs to the object at ffff888097a17000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 0 bytes inside of 2048-byte region [ffff888097a17000, ffff888097a17800) The buggy address belongs to the page: page:ffffea00025e85c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea00025172c8 ffffea000250bb88 ffff8880aa400e00 raw: 0000000000000000 ffff888097a17000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888097a16f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888097a16f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff888097a17000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888097a17080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888097a17100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================