Description of problem:
Accessing byte-aligned data through uint16_t pointers can cause crashes
on some platforms or reduce the performance. This bug is in libvncserver which is bundled in vino.
Version-Release number of selected component (if applicable):
I have not been able to reproduce this but it is acknowledged upstream here: https://github.com/LibVNC/libvncserver/commit/53073c8d7e232151ea2ecd8a1243124121e10e2d
Can cause slow downs or crashes on ARM.
rfbSetClientColourMapBGR233() behaves normally without performance issues or crashes.
Note that this bug was originally picked up as a CVE/security issue. However, during analysis and after speaking with upstream developer Toby Junghans, we determined there is no security risk and this is a trivial reliability bug at most. I am filing this to let the maintainer know about the issue. I checked the code shipped in RHEL7 and found that the bug exists via code examination.
It is pretty late for RHEL 7, let's reconsider this for RHEL 8 (Bug 1861933).