CVSROOT: /cvs
Module name: src
Changes by: o...@cvs.openbsd.org 2023/06/04 00:58:33
Modified files:
lib/libc/stdlib: malloc.3 malloc.c
regress/lib/libc/malloc/malloc_errs: malloc_errs.c
Log message:
More thorough write-afetr-free checks.
On free, chunks (the pieces of a pages used for smaller allocations)
are junked and then validated after they leave the delayed free
list. So after free, a chunk always contains junk bytes. This means
that if we start with the right contents for a new page of chunks,
we can *validate* instead of *write* junk bytes when (re)-using a
chunk.
With this, we can detect write-after-free when a chunk is recycled,
not justy when a chunk is in the delayed free list. We do a little
bit more work on initial allocation of a page of chunks and when
re-using (as we validate now even on junk level 1).
Also: some extra consistency checks for recallocaray(3) and fixes
in error messages to make them more consistent, with man page bits.
Plus regress additions.
