09.04.2023 13:53, Michael Tokarev wrote:
linux-user getgroups(), setgroups(), getgroups32() and setgroups32() used alloca() to allocate grouplist arrays, with unchecked gidsetsize coming from the "guest". With NGROUPS_MAX being 65536 (linux, and it is common for an application to allocate NGROUPS_MAX for getgroups()), this means a typical allocation is half the megabyte on the stack. Which just overflows stack, which leads to immediate SIGSEGV in actual system getgroups() implementation.
Ping? Thanks, /mjt