------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 0 PID: 8034 at lib/refcount.c:28 refcount_warn_saturate+0x14a/0x210 lib/refcount.c:28 Modules linked in: CPU: 0 UID: 0 PID: 8034 Comm: kbnepd bnep0 Not tainted 6.16.0-rc3-syzkaller-00072-gee88bddf7f2f #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:refcount_warn_saturate+0x14a/0x210 lib/refcount.c:28 Code: ff 89 de e8 98 c3 e2 fc 84 db 0f 85 66 ff ff ff e8 ab c8 e2 fc c6 05 b9 ca b7 0b 01 90 48 c7 c7 60 11 15 8c e8 d7 db a1 fc 90 <0f> 0b 90 90 e9 43 ff ff ff e8 88 c8 e2 fc 0f b6 1d 94 ca b7 0b 31 RSP: 0018:ffffc9000754f938 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff817aa1a8 RDX: ffff88806ad74880 RSI: ffffffff817aa1b5 RDI: 0000000000000001 RBP: ffff88805d162c78 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffff8880286f6800 R13: ffff88805d162c78 R14: ffffffff86079e10 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888097560000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000057ece4c0 CR3: 0000000053e9f000 CR4: 0000000000352ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __refcount_sub_and_test include/linux/refcount.h:400 [inline] __refcount_dec_and_test include/linux/refcount.h:432 [inline] refcount_dec_and_test include/linux/refcount.h:450 [inline] kref_put include/linux/kref.h:64 [inline] klist_dec_and_del lib/klist.c:206 [inline] klist_put+0x11b/0x1b0 lib/klist.c:217 device_del+0x1d8/0x9f0 drivers/base/core.c:3858 unregister_netdevice_many_notify+0x1903/0x2700 net/core/dev.c:12112 unregister_netdevice_many net/core/dev.c:12140 [inline] unregister_netdevice_queue+0x305/0x3f0 net/core/dev.c:11984 unregister_netdevice include/linux/netdevice.h:3379 [inline] unregister_netdev+0x1f/0x60 net/core/dev.c:12158 bnep_session+0x224e/0x2d80 net/bluetooth/bnep/core.c:525 kthread+0x3c5/0x780 kernel/kthread.c:464 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245