glibc/sysdeps/s390/nptl
Szabolcs Nagy 238032ead6 aarch64: enforce >=64K guard size [BZ #26691]
There are several compiler implementations that allow large stack
allocations to jump over the guard page at the end of the stack and
corrupt memory beyond that. See CVE-2017-1000364.

Compilers can emit code to probe the stack such that the guard page
cannot be skipped, but on aarch64 the probe interval is 64K by default
instead of the minimum supported page size (4K).

This patch enforces at least 64K guard on aarch64 unless the guard
is disabled by setting its size to 0.  For backward compatibility
reasons the increased guard is not reported, so it is only observable
by exhausting the address space or parsing /proc/self/maps on linux.

On other targets the patch has no effect. If the stack probe interval
is larger than a page size on a target then ARCH_MIN_GUARD_SIZE can
be defined to get large enough stack guard on libc allocated stacks.

The patch does not affect threads with user allocated stacks.

Fixes bug 26691.
2020-10-02 09:57:44 +01:00
..
bits semaphore: consolidate arch headers into a generic one 2020-05-06 13:07:12 -07:00
Makefile Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00
pthread-offsets.h nptl: Add tests for internal pthread_rwlock_t offsets 2019-11-26 13:53:36 +00:00
pthreaddef.h aarch64: enforce >=64K guard size [BZ #26691] 2020-10-02 09:57:44 +01:00
tcb-offsets.sym Remove cached PID/TID in clone 2016-11-24 19:38:51 -02:00
tls.h Update copyright dates with scripts/update-copyrights. 2020-01-01 00:14:33 +00:00