I am experiencing a related issue which is caused by calling the JNI JVM init from python.
Steps to reproduce: 1. cd /usr/lib/x86_64-linux-gnu 2. sudo ln -s libpython3.5m.a libpython3.5.a 3. sudo ln -s libpython3.5m.so libpython3.5.so 4. python3 -m virtualenv -p python3 venv3 5. source venv3/bin/activate 6. JCC_JDK=/usr/lib/jvm/java-8-openjdk-amd64 7. pip install jcc --no-cache-dir 8. python -m jcc --package java.lang Results obtained: SEGV Results expected: command exits normally Using 4.9.0-1 (pre-patch for CVE-2017-1000364): command exits normally. It also works to run python under GDB, break before the JVM calls os::pd_create_stack_guard_pages (os_linux.cpp:2985) and read enough stack pages (using x/x) to force the kernel to move the stack guard far enough for successful execution. This is similar behavior to compiling C code with -fstack-check, which I assume Python is. os::pd_create_stack_guard_pages calls mmap() to create the JVM's own stack-guard pages (which are now unneeded?) which seems to cause linux kernel to no longer be able to detect when the kernel's stack guard pages need to be advanced down so the stack guard is then stuck in place at whatever the largest size of the stack was when os::pd_create_stack_guard_pages was called. The JVM isn't expecting a (kernel-created) stack-guard page at this location so it grows the stack (using alloca()), tries to write to it and SEGV. Before os::pd_create_stack_guard_pages the linux kernel correctly detects the page at the top of the stack as the stack page, as reported by pmap(1) or (gdb) info proc maps. The stack pages are marked by the kernel as [stack]. After os::pd_create_stack_guard_pages the linux kernel no longer correctly detects the page the top of the stack as the stack page as reported by pmap(1) or (gdb) info proc maps. The stack pages are NO LONGER marked by the kernel as [stack]; and the kernel stack-guard page is now frozen in place for the remainder of the process execution. -- Joshua Charles Campbell Ph.D. Student and Research Assistant Department of Computing Science University of Alberta josh...@ualberta.ca
