------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 3 PID: 32510 at lib/refcount.c:28 refcount_warn_saturate+0x14a/0x210 lib/refcount.c:28 Modules linked in: CPU: 3 UID: 0 PID: 32510 Comm: kbnepd ò“ Not tainted 6.14.0-rc5-syzkaller-00268-g1110ce6a1e34 #0 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 44 f7 fc 84 db 0f 85 66 ff ff ff e8 eb 49 f7 fc c6 05 27 69 88 0b 01 90 48 c7 c7 60 05 d3 8b e8 67 7a b7 fc 90 <0f> 0b 90 90 e9 43 ff ff ff e8 c8 49 f7 fc 0f b6 1d 02 69 88 0b 31 RSP: 0018:ffffc900030d7948 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff817a2269 RDX: ffff888022d54880 RSI: ffffffff817a2276 RDI: 0000000000000001 RBP: ffff888026e47878 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000003 R12: ffff888022672400 R13: ffff888026e47878 R14: ffffffff85ea1360 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff88802b700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000f5209016 CR3: 00000000277c2000 CR4: 0000000000352ef0 DR0: fffffffffffffffc DR1: 0000000000000006 DR2: 0200000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __refcount_sub_and_test include/linux/refcount.h:275 [inline] __refcount_dec_and_test include/linux/refcount.h:307 [inline] refcount_dec_and_test include/linux/refcount.h:325 [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+0x1d9/0x9f0 drivers/base/core.c:3831 unregister_netdevice_many_notify+0x13aa/0x1f30 net/core/dev.c:11920 unregister_netdevice_many net/core/dev.c:11948 [inline] unregister_netdevice_queue+0x307/0x3f0 net/core/dev.c:11818 unregister_netdevice include/linux/netdevice.h:3337 [inline] unregister_netdev+0x1f/0x60 net/core/dev.c:11966 bnep_session+0x21b6/0x2ca0 net/bluetooth/bnep/core.c:525 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244