performance: 0.854
device: 0.793
graphic: 0.777
network: 0.747
peripherals: 0.740
ppc: 0.715
vnc: 0.670
register: 0.668
hypervisor: 0.658
permissions: 0.653
user-level: 0.645
risc-v: 0.631
semantic: 0.610
VMM: 0.609
files: 0.585
virtual: 0.583
arm: 0.571
TCG: 0.570
architecture: 0.544
i386: 0.535
mistranslation: 0.535
socket: 0.532
debug: 0.528
KVM: 0.508
x86: 0.500
PID: 0.475
kernel: 0.462
boot: 0.436
assembly: 0.168

Segfault in libvhost-user and libvduse because of invalid pointer arithmetic with indirect read
Description of problem:
Hello, this is my first experience communicating with open-source community. I have already reported the problem and have submitted patches through qemu-devel mailing list https://mail.gnu.org/archive/html/qemu-devel/2024-01/msg02533.html, as instructed in https://www.qemu.org/docs/master/devel/submitting-a-patch.html, albeit getting no response from any maintainer. I know, that everyone are very busy and are spammed everyday from millions of threads, but I am getting very upset, that such a trivial bug lives in code base for many years and even have been copied to "sister"-library without proper review. So, excuse me, if I am taking this issue too personally.

The problem - when one tries to use libvhost-user\libvduse and triggers for some reason non-zero-copy mode (like pushing a lot of data) of indirect descriptor reading routine `virtqueue_read_indirect_desc`, any time one got to read more than one descriptor - one would overwrite stack and depending on one's luck getting some weird behaviour, or simple crash moments later, when other code tries to access broken data.

Steps to reproduce are non-trivial, because depends on one's host and VM (one simply gets random crashes here and there, with core dumps pointing somewhere around given libraries), but anyone who can read C code, can clearly see that pointer arithmetic of `struct vring_desc *desc` is wrong.

Maybe, I got instructions wrong and posted fixes to wrong mailing list, maybe, nobody cares, so thank you for attention. I'll be glad to hear any advice on how can I help with fixing this simple error, besides what has been done already.

Thank you.