Re: brk() in v6.1-rc1 can expand file mappings, seemingly without taking file locks

[Jann Horn]

On Fri, Dec 2, 2022 at 7:53 PM Jann Horn <jannh@xxxxxxxxxx> wrote:
> As of commit ca57f02295f, brk() can expand ordinary file mappings (but

Sorry, that was worded confusingly - I meant "ca57f02295f is the
commit from Linus' tree on top of which I was testing".

The broken code seems to have been introduced in
commit 2e7ce7d354f2 ("mm/mmap: change do_brk_flags() to expand
existing VMA and add do_brk_munmap()").