vnc: 0.903
network: 0.884
device: 0.865
socket: 0.784
risc-v: 0.733
performance: 0.699
semantic: 0.673
architecture: 0.631
register: 0.617
graphic: 0.616
kernel: 0.605
files: 0.586
ppc: 0.553
boot: 0.494
arm: 0.483
virtual: 0.465
VMM: 0.414
mistranslation: 0.409
i386: 0.358
TCG: 0.355
PID: 0.354
debug: 0.333
x86: 0.325
hypervisor: 0.307
permissions: 0.296
KVM: 0.295
user-level: 0.278
peripherals: 0.242
assembly: 0.137

VNC/RFB: QEMU reports incorrect name (length)

If the name of a machine (as set with the -name argument) has a length longer than 1024, (RFB) VNC clients will not receive a correct RFB ServerInit message.

I suspect this is the problem:

https://github.com/qemu/qemu/blob/master/ui/vnc.c#L2463

The return value of snprintf is used as the value for the name-length field in the ServerInit message.
This is problematic for names that were truncated to 1024, as the length will now be bigger than the actual name.

I think a quick fix would be to simply report min(size,1024) to the client...

The right fix here is to switch to use g_strdup_printf and avoid a fixed length stack buffer entirely.

Fix has been committed: http://git.qemu.org/?p=qemu.git;a=commitdiff;h=97efe4f961dcf5a0126