[syslinux] [PATCH 0/2] Stack overflows when running commands

[Gene Cumm]

On Tue, Oct 13, 2015 at 12:04 AM, celelibi--- via Syslinux
<syslinux at zytor.com> wrote:
> From: Sylvain Gault <sylvain.gault at gmail.com>
>
> Hello there,
>
> I propose 2 patches that fix two possible stack overflows either when running a
> COM32 module or when loading a new config file.
>
> I didn't find a better way to do this than to use the infamous setjmp/longjmp
> functions to restore the stack to a previous state. This makes the logic a bit
> more complex, but the behavior is not changed.

The other way to do this is set variable(s) about the next target
state and then return from the functions.  I'm not sure which is the
better way, however.

> Although these bugs are not very visible right now because of some useless
> section in the binaries taking some space allowing the stack to overflow
> without consequences, they might need to be fixed very soon.
>
> Still remain a limitation when running a lot of commands (or loading lots of
> time some config file) is that some files might not be closed and some memory
> may not be freed.
>
> Sylvain Gault (2):
>   ldlinux: fix stack overflow when running COM32 modules
>   core: Fix stack overflow when reloading config
>
>  com32/elflink/ldlinux/execute.c |  4 ++-
>  com32/elflink/ldlinux/ldlinux.c | 28 ++++++++++++++------
>  core/elflink/load_env32.c       | 58 ++++++++++++++++++++++++++++++++++++++++-
>  3 files changed, 80 insertions(+), 10 deletions(-)


-- 
-Gene