refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 14 at lib/refcount.c:28 refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28
Modules linked in:
CPU: 0 PID: 14 Comm: ksoftirqd/0 Not tainted 5.15.178-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
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 : ffff80001bd47b40
x29: ffff80001bd47b40 x28: fffffbffefff38c0 x27: 1fffe0001992b083
x26: 1fffe0001992b083 x25: 0000000000000000 x24: 0000000000000001
x23: dfff800000000000 x22: fffffbffefff3988 x21: 0000000000000003
x20: ffff0000cc9584e8 x19: ffff800016fd0000 x18: 0000000000000101
x17: 202944414552283a x16: ffff8000082ec940 x15: 20726f7463657320
x14: 1ffff0000296e06c x13: dfff800000000000 x12: 0000000000000003
x11: 0000000000000100 x10: 0000000000000000 x9 : be60403b0faac900
x8 : be60403b0faac900 x7 : 0000000000000000 x6 : 0000000000000000
x5 : 0000000000000080 x4 : 0000000000000000 x3 : ffff800008046154
x2 : 0000000000000001 x1 : 0000000000000100 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+0x68/0x88 block/blk-mq.c:577
 nbd_complete_rq+0x48/0x154 drivers/block/nbd.c:360
 blk_complete_reqs block/blk-mq.c:587 [inline]
 blk_done_softirq+0x11c/0x168 block/blk-mq.c:592
 handle_softirqs+0x384/0xdbc kernel/softirq.c:558
 run_ksoftirqd+0x6c/0x29c kernel/softirq.c:925
 smpboot_thread_fn+0x4b0/0x920 kernel/smpboot.c:164
 kthread+0x37c/0x45c kernel/kthread.c:334
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870
irq event stamp: 663245
hardirqs last  enabled at (663244): [<ffff80000832af8c>] console_unlock+0xc7c/0x1394 kernel/printk/printk.c:2748
hardirqs last disabled at (663245): [<ffff800011b49ab0>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:396
softirqs last  enabled at (663212): [<ffff8000081b6920>] softirq_handle_end kernel/softirq.c:401 [inline]
softirqs last  enabled at (663212): [<ffff8000081b6920>] handle_softirqs+0xb88/0xdbc kernel/softirq.c:586
softirqs last disabled at (663217): [<ffff8000081b9450>] run_ksoftirqd+0x6c/0x29c kernel/softirq.c:925
---[ end trace ba21d221a3d8a13f ]---