This patchset removes two variable length arrays from the jack audio backend. The codebase has very few VLAs, and if we can get rid of them all we can make the compiler error on new additions. This is a defensive measure against security bugs where an on-stack dynamic allocation isn't correctly size-checked (e.g. CVE-2021-3527).
The first one is fairly straightforward (although the JACK API's requirement that (a) you don't pass it an overlong client name and (b) that maximum length is provided by calling a function, not as a compile time constant makes it a little less clean than it might be. The second one avoids the dynamic allocation, but if the audio subsystem has a compile-time upper bound on the number of channels then we could use a fixed-size stack array rather than the awkward "allocate a working buffer at init time" that I have in this patch. Suggestions for improvements welcome. Disclaimer: tested only with "make check", which doesn't actually exercise the audio subsystem. thanks -- PMM Peter Maydell (2): audio/jackaudio: Avoid dynamic stack allocation in qjack_client_init audio/jackaudio: Avoid dynamic stack allocation in qjack_process() audio/jackaudio.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) -- 2.34.1
