Commit Graph

11 Commits

Author SHA1 Message Date
Evan Gates
ad6da18ca6 increment pointer by runelen(delim) not 1 2015-03-13 13:42:03 +00:00
833c2aebb4 Remove mallocarray(...) and use reallocarray(NULL, ...)
After a short correspondence with Otto Moerbeek it turned out
mallocarray() is only in the OpenBSD-Kernel, because the kernel-
malloc doesn't have realloc.
Userspace applications should rather use reallocarray with an
explicit NULL-pointer.

Assuming reallocarray() will become available in c-stdlibs in the
next few years, we nip mallocarray() in the bud to allow an easy
transition to a system-provided version when the day comes.
2015-03-11 10:50:18 +01:00
3c33abc520 Implement mallocarray()
A function used only in the OpenBSD-Kernel as of now, but it surely
provides a helpful interface when you just don't want to make sure
the incoming pointer to erealloc() is really NULL so it behaves
like malloc, making it a bit more safer.

Talking about *allocarray(): It's definitely a major step in code-
hardening. Especially as a system administrator, you should be
able to trust your core tools without having to worry about segfaults
like this, which can easily lead to privilege escalation.

How do the GNU coreutils handle this?
$ strings -n 4611686018427387903
strings: invalid minimum string length -1
$ strings -n 4611686018427387904
strings: invalid minimum string length 0

They silently overflow...

In comparison, sbase:

$ strings -n 4611686018427387903
mallocarray: out of memory
$ strings -n 4611686018427387904
mallocarray: out of memory

The first out of memory is actually a true OOM returned by malloc,
whereas the second one is a detected overflow, which is not marked
in a special way.
Now tell me which diagnostic error-messages are easier to understand.
2015-03-10 22:19:19 +01:00
3b825735d8 Implement reallocarray()
Stateless and I stumbled upon this issue while discussing the
semantics of read, accepting a size_t but only being able to return
ssize_t, effectively lacking the ability to report successful
reads > SSIZE_MAX.
The discussion went along and we came to the topic of input-based
memory allocations. Basically, it was possible for the argument
to a memory-allocation-function to overflow, leading to a segfault
The OpenBSD-guys came up with the ingenious reallocarray-function,
and I implemented it as ereallocarray, which automatically returns
on error.
Read more about it here[0].

A simple testcase is this (courtesy to stateless):
$ sbase-strings -n (2^(32|64) / 4)

This will segfault before this patch and properly return an OOM-
situation afterwards (thanks to the overflow-check in reallocarray).

2015-03-10 21:23:36 +01:00
804b62f7a2 Fix broken sbase-box due to multiple definitions of usage 2015-02-28 18:33:33 +00:00
Hiltjo Posthuma
31f0624f3d code-style: minor cleanup and nitpicking 2015-02-20 13:29:38 +01:00
767e36e410 sed(1): Add back line numbers to compiler error messages 2015-02-18 11:43:34 +01:00
4391984115 Use e-functions in sed(1)
and take off the tin-foil-head by removing checks for printf-return-
2015-02-18 11:21:56 +01:00
a98405d277 Refactor sed(1) a bit
Well, isspacerune() has been fixed and some other FIXME's were also easy
to do.
There are some places where maybe some util-functions could be helpful.
In some cases, like for instance in regard to escape-sequences, I'm all
for consistency rather than adhering to the POSIX-standard too much.
Relying on centralized util-functions also makes it possible to keep
this consistency across the board.
2015-02-18 10:51:39 +01:00
31572c8b0e Clean up #includes 2015-02-14 21:12:23 +01:00
Evan Gates
bc07f1b9b5 Add initial implementation of sed(1)
No manpage yet.
2015-02-10 10:35:22 +00:00