syzbot has found a reproducer for the following issue on: HEAD commit: ac3a0c84 Merge git://git.kernel.org/pub/scm/linux/kernel/g.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1194935c900000 kernel config: https://syzkaller.appspot.com/x/.config?x=e59ee776d5aa8d55 dashboard link: https://syzkaller.appspot.com/bug?extid=2e9900a1e1b3c9c96a77 compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10b7ddca900000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=126dcf6c900000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+2e9900a1e1b3c9c96a77@xxxxxxxxxxxxxxxxxxxxxxxxx ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 1 PID: 2540 at lib/refcount.c:28 refcount_warn_saturate+0x15b/0x1a0 lib/refcount.c:28 Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 2540 Comm: kworker/1:8 Not tainted 5.8.0-rc7-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 panic+0x264/0x7a0 kernel/panic.c:231 __warn+0x227/0x250 kernel/panic.c:600 report_bug+0x1b1/0x2e0 lib/bug.c:198 handle_bug+0x42/0x80 arch/x86/kernel/traps.c:235 exc_invalid_op+0x16/0x40 arch/x86/kernel/traps.c:255 asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:540 RIP: 0010:refcount_warn_saturate+0x15b/0x1a0 lib/refcount.c:28 Code: c7 8a af 14 89 31 c0 e8 b3 f2 a8 fd 0f 0b eb 85 e8 2a 32 d7 fd c6 05 a4 d9 eb 05 01 48 c7 c7 b6 af 14 89 31 c0 e8 95 f2 a8 fd <0f> 0b e9 64 ff ff ff e8 09 32 d7 fd c6 05 84 d9 eb 05 01 48 c7 c7 RSP: 0018:ffffc90007d27c48 EFLAGS: 00010246 RAX: adb9104953f59b00 RBX: 0000000000000003 RCX: ffff8880a02d0540 RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000 RBP: 0000000000000003 R08: ffffffff815dd389 R09: ffffed1015d262c0 R10: ffffed1015d262c0 R11: 0000000000000000 R12: dffffc0000000000 R13: ffff8880a0259118 R14: dffffc0000000000 R15: ffff8880ae9350c0 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 Kernel Offset: disabled Rebooting in 86400 seconds..
