------------[ cut here ]------------ refcount_t: decrement hit 0; leaking memory. WARNING: lib/refcount.c:31 at refcount_warn_saturate+0x70/0x110 lib/refcount.c:31, CPU#1: syz.0.7057/31630 Modules linked in: CPU: 1 UID: 0 PID: 31630 Comm: syz.0.7057 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026 RIP: 0010:refcount_warn_saturate+0x70/0x110 lib/refcount.c:31 Code: c6 00 28 f0 8e e8 10 13 17 fd 83 fb 01 7e 22 83 fb 02 74 39 83 fb 03 74 47 83 fb 04 75 68 e8 77 0d 17 fd 48 8d 3d 30 70 6d 0b <67> 48 0f b9 3a eb 66 85 db 74 3e 83 fb 01 75 4c e8 5b 0d 17 fd 48 RSP: 0018:ffffc9000cbdfb08 EFLAGS: 00010293 RAX: ffffffff84ae8bf9 RBX: 0000000000000004 RCX: ffff88804b5e9e80 RDX: 0000000000000000 RSI: ffffffff8ef02800 RDI: ffffffff901bfc30 RBP: ffffc9000cbdfc60 R08: ffff88804b5e9e80 R09: 0000000000000005 R10: 0000000000000004 R11: 0000000000000000 R12: f8f8f8f8f8f8f8f8 R13: dffffc0000000000 R14: ffff888034116668 R15: 0000000000000001 FS: 00005555772e8500(0000) GS:ffff888125565000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c3d7900 CR3: 0000000083d7e000 CR4: 00000000003526f0 Call Trace: __refcount_dec include/linux/refcount.h:461 [inline] refcount_dec include/linux/refcount.h:476 [inline] ref_tracker_free+0x6fc/0x840 lib/ref_tracker.c:298 netdev_tracker_free include/linux/netdevice.h:4423 [inline] netdev_put include/linux/netdevice.h:4440 [inline] dev_put include/linux/netdevice.h:4466 [inline] mpoad_close+0x1fc/0x3e0 net/atm/mpc.c:889 vcc_destroy_socket net/atm/common.c:181 [inline] vcc_release+0x10f/0x580 net/atm/common.c:205 __sock_release net/socket.c:656 [inline] sock_close+0xc3/0x240 net/socket.c:1448 __fput+0x44f/0xa70 fs/file_table.c:469 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:67 [inline] exit_to_user_mode_loop+0xed/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe20d19c799 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd9bdb8748 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007fe20d417da0 RCX: 00007fe20d19c799 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fe20d417da0 R08: 0000000000000006 R09: 0000000000000000 R10: 00007fe20d417cb0 R11: 0000000000000246 R12: 00000000000f3cad R13: 00007fe20d41627c R14: 00000000000f3ac2 R15: 00007ffd9bdb8850 ---------------- Code disassembly (best guess), 5 bytes skipped: 0: e8 10 13 17 fd call 0xfd171315 5: 83 fb 01 cmp $0x1,%ebx 8: 7e 22 jle 0x2c a: 83 fb 02 cmp $0x2,%ebx d: 74 39 je 0x48 f: 83 fb 03 cmp $0x3,%ebx 12: 74 47 je 0x5b 14: 83 fb 04 cmp $0x4,%ebx 17: 75 68 jne 0x81 19: e8 77 0d 17 fd call 0xfd170d95 1e: 48 8d 3d 30 70 6d 0b lea 0xb6d7030(%rip),%rdi # 0xb6d7055 * 25: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction 2a: eb 66 jmp 0x92 2c: 85 db test %ebx,%ebx 2e: 74 3e je 0x6e 30: 83 fb 01 cmp $0x1,%ebx 33: 75 4c jne 0x81 35: e8 5b 0d 17 fd call 0xfd170d95 3a: 48 rex.W