bitreader: Simplify & fix a read stack buffer overflow

The current implementation was always reading the next byte, regardless of the buffer size. This commit simplifies the existing code and ensures we never read past the input buffer

Fix #16

marked this merge request as draft

Marking as draft since I completely overlooked the callsites and haven't tested this in VLC yet

added 2 commits

• e691238a - bitreader: Add a minimal test
• a8c859e5 - bitreader: Simplify & fix a read stack buffer overflow

Compare with previous version

Submitted a V2 which doesn't include bound checking this will probably propagate in many callsites, including in other projects.

marked this merge request as ready

why is there no check for state->start overflow ?

Mostly because this meant a quite larger changeset since most callsites don't have the buffer size available, and it didn't fix the issue itself.

I was planning on doing that in a different MR but I can modify this one if you prefer

Please modify this one.

Done.

This goes with the dvdnav counterpart: libdvdnav!25

added 3 commits

• 4deaa0da - bitreader: Simplify & fix a read stack buffer overflow
• 21ae7a50 - nav_read: Pass the buffer size as a 3rd parameter
• 9ab443e4 - bitreader: Provide the buffer size

Compare with previous version

mentioned in merge request libdvdnav!25

added 6 commits

• 9ab443e4...3ac69796 - 2 commits from branch videolan:master
• 42c7a6dc - bitreader: Add a minimal test
• efc76220 - bitreader: Simplify & fix a read stack buffer overflow
• 000e15a5 - nav_read: Pass the buffer size as a 3rd parameter
• 4075c6c7 - bitreader: Provide the buffer size

Compare with previous version

mentioned in merge request !27 (merged)

mentioned in merge request !31

mentioned in merge request libdvdnav!50

mentioned in merge request vlc!2377 (closed)