------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 1 PID: 4260 at lib/refcount.c:28 refcount_warn_saturate+0xad/0x130 lib/refcount.c:28
Modules linked in:
CPU: 1 UID: 0 PID: 4260 Comm: syz.3.16 Not tainted 6.13.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:refcount_warn_saturate+0xad/0x130 lib/refcount.c:28
Code: 6a ff 90 0f 0b 90 90 c3 cc cc cc cc 80 3d a1 7f cf 02 00 75 97 c6 05 98 7f cf 02 01 90 48 c7 c7 62 55 ce 83 e8 34 c3 6a ff 90 <0f> 0b 90 90 c3 cc cc cc cc 80 3d 77 7f cf 02 00 0f 85 6c ff ff ff
RSP: 0018:ffffc9000364fc80 EFLAGS: 00010246
RAX: 603bfb9eba684000 RBX: ffff8881110cde00 RCX: 0000000000000002
RDX: 0000000000000002 RSI: c0000000ffffdfff RDI: 00000000ffffffff
RBP: 0000000000000000 R08: ffffffff8432c850 R09: 00000000ffffdfff
R10: 0000000000000000 R11: 3fffffffffffffff R12: ffff888121793000
R13: ffff8881110cde78 R14: ffff888108311c00 R15: ffffffffffffbfff
FS:  00007fcc2072e6c0(0000) GS:ffff88813bb00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000040 CR3: 0000000111af6000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 io_notif_flush io_uring/notif.h:40 [inline]
 io_send_zc_cleanup+0x4c/0x60 io_uring/net.c:1222
 io_clean_op+0x140/0x200 io_uring/io_uring.c:406
 io_free_batch_list io_uring/io_uring.c:1429 [inline]
 __io_submit_flush_completions+0x3d5/0x420 io_uring/io_uring.c:1470
 io_submit_flush_completions io_uring/io_uring.h:159 [inline]
 ctx_flush_and_put+0x39/0xc0 io_uring/io_uring.c:1031
 io_handle_tw_list+0x135/0x160 io_uring/io_uring.c:1071
 tctx_task_work_run+0x4b/0x140 io_uring/io_uring.c:1123
 tctx_task_work+0x34/0x80 io_uring/io_uring.c:1141
 task_work_run+0x82/0xb0 kernel/task_work.c:239
 get_signal+0x65/0x6d0 kernel/signal.c:2809
 arch_do_signal_or_restart+0x89/0x2a0 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+0x65/0x1f0 kernel/entry/common.c:218
 do_syscall_64+0xed/0x1f0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcc1f98d169
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:00007fcc2072e038 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: 0000000000001000 RBX: 00007fcc1fba5fa0 RCX: 00007fcc1f98d169
RDX: 0000000000000000 RSI: 00000000000047bc RDI: 0000000000000007
RBP: 00007fcc1fa0e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000021 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fcc1fba5fa0 R15: 00007fff10d7d418
 </TASK>