------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 1 PID: 149 at lib/refcount.c:28 refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28 Modules linked in: CPU: 1 PID: 149 Comm: kworker/1:1H Not tainted 5.15.173-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: kblockd blk_mq_run_work_fn pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28 lr : refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28 sp : ffff80001d807590 x29: ffff80001d807590 x28: fffffbffefff2fc0 x27: 1fffe000198c3703 x26: 1fffe000198c3703 x25: 0000000000000000 x24: 0000000000000001 x23: dfff800000000000 x22: fffffbffefff3088 x21: 0000000000000003 x20: ffff0000cc61b8e8 x19: ffff800016fbd000 x18: 0000000000000001 x17: 0000000000000000 x16: ffff800011b4c108 x15: 0000000000000012 x14: 1ffff0000296c06c x13: dfff800000000000 x12: 0000000000000001 x11: 0000000000000000 x10: 0000000000000000 x9 : 65dc91182626e300 x8 : 65dc91182626e300 x7 : 0000000000000000 x6 : 0000000000000000 x5 : 0000000000000080 x4 : 0000000000000000 x3 : ffff80000aa0ed5c x2 : ffff0001b4198d10 x1 : 0000000100000000 x0 : 0000000000000026 Call trace: refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28 __refcount_sub_and_test include/linux/refcount.h:283 [inline] __refcount_dec_and_test include/linux/refcount.h:315 [inline] refcount_dec_and_test include/linux/refcount.h:333 [inline] blk_mq_free_request+0x440/0x584 block/blk-mq.c:543 __blk_mq_end_request+0x318/0x350 block/blk-mq.c:568 blk_mq_end_request block/blk-mq.c:577 [inline] blk_mq_dispatch_rq_list+0x9c8/0x14ac block/blk-mq.c:1408 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:200 [inline] blk_mq_do_dispatch_sched+0x8b4/0x9f4 block/blk-mq-sched.c:214 __blk_mq_sched_dispatch_requests+0x310/0x420 blk_mq_sched_dispatch_requests+0xbc/0x138 block/blk-mq-sched.c:366 __blk_mq_run_hw_queue block/blk-mq.c:1511 [inline] blk_mq_run_work_fn+0x150/0x208 block/blk-mq.c:1842 process_one_work+0x790/0x11b8 kernel/workqueue.c:2310 worker_thread+0x910/0x1034 kernel/workqueue.c:2457 kthread+0x37c/0x45c kernel/kthread.c:334 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870 irq event stamp: 24292 hardirqs last enabled at (24291): [] console_unlock+0xc7c/0x1394 kernel/printk/printk.c:2748 hardirqs last disabled at (24292): [] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:396 softirqs last enabled at (24262): [] softirq_handle_end kernel/softirq.c:401 [inline] softirqs last enabled at (24262): [] handle_softirqs+0xb88/0xdbc kernel/softirq.c:586 softirqs last disabled at (24257): [] __do_softirq kernel/softirq.c:592 [inline] softirqs last disabled at (24257): [] do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline] softirqs last disabled at (24257): [] invoke_softirq kernel/softirq.c:439 [inline] softirqs last disabled at (24257): [] __irq_exit_rcu+0x268/0x4d8 kernel/softirq.c:641 ---[ end trace 7d5808ba3aa2d308 ]--- blk_update_request: I/O error, dev nbd1, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 Buffer I/O error on dev nbd1, logical block 0, async page read blk_update_request: I/O error, dev nbd1, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 Buffer I/O error on dev nbd1, logical block 0, async page read blk_update_request: I/O error, dev nbd1, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 0 Buffer I/O error on dev nbd1, logical block 0, async page read