Guard against ArgV overflow in Linux IterateCommandlineArgs

The Linux branch walked /proc/self/cmdline into a fixed-size 255-entry
array with no bounds check. A command line with more than 255
arguments (not unusual for build invocations, find-xargs pipelines,
and CI drivers) wrote past the end of the local buffer and corrupted
the stack.

The fix needs to stay on the stack because IterateCommandlineArgs can
run during static initialization, before our memory allocators are
wired up, so heap-backed containers like std::vector are not safe
here. Keep the fixed-size buffer, add a comment explaining the
allocator constraint, and drop (with free()) any argv entries beyond
kMaxArgs instead of writing them past the end of the array.

0 files changed, 0 insertions, 0 deletions