------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 1 PID: 16576 at lib/refcount.c:28 refcount_warn_saturate+0x15a/0x1d0 lib/refcount.c:28 Modules linked in: CPU: 1 UID: 0 PID: 16576 Comm: syz.1.2684 Not tainted 6.14.0-rc7-syzkaller-00186-gd07de43e3f05 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:refcount_warn_saturate+0x15a/0x1d0 lib/refcount.c:28 Code: c0 e1 7f 8c e8 d7 bc 93 fc 90 0f 0b 90 90 eb 99 e8 6b 01 d4 fc c6 05 97 15 38 0b 01 90 48 c7 c7 20 e2 7f 8c e8 b7 bc 93 fc 90 <0f> 0b 90 90 e9 76 ff ff ff e8 48 01 d4 fc c6 05 71 15 38 0b 01 90 RSP: 0018:ffffc9000d3478c0 EFLAGS: 00010246 RAX: 68fbd2ed2ee09200 RBX: ffff8880619bb010 RCX: 0000000000080000 RDX: ffffc90004b72000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: 0000000000000003 R08: ffffffff81819d62 R09: fffffbfff1d3a69c R10: dffffc0000000000 R11: fffffbfff1d3a69c R12: dffffc0000000000 R13: 1ffff1100608c380 R14: 1ffff1100c3375be R15: ffff8880619badf0 FS: 00007fb3084976c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa180ff7524 CR3: 000000007edc2000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 000000000000fe00 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: io_notif_flush io_uring/notif.h:40 [inline] io_send_zc_cleanup+0x121/0x170 io_uring/net.c:1222 io_clean_op+0x58c/0x9a0 io_uring/io_uring.c:406 io_free_batch_list io_uring/io_uring.c:1429 [inline] __io_submit_flush_completions+0xc16/0xd20 io_uring/io_uring.c:1470 io_submit_flush_completions io_uring/io_uring.h:159 [inline] ctx_flush_and_put io_uring/io_uring.c:1031 [inline] io_handle_tw_list+0x473/0x500 io_uring/io_uring.c:1071 tctx_task_work_run+0x9a/0x370 io_uring/io_uring.c:1123 tctx_task_work+0x9a/0x100 io_uring/io_uring.c:1141 task_work_run+0x24f/0x310 kernel/task_work.c:227 get_signal+0x15d1/0x1720 kernel/signal.c:2809 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb30758d169 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fb308497038 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa RAX: 0000000000001000 RBX: 00007fb3077a5fa0 RCX: 00007fb30758d169 RDX: 0000000000000000 RSI: 00000000000047bc RDI: 0000000000000007 RBP: 00007fb30760e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000021 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fb3077a5fa0 R15: 00007ffd41694378