Catalin Marinas 95236ae76b mm: Avoid creating virtual address aliases in brk()/mmap()/mremap() ... commit dcde237319 upstream. Currently the arm64 kernel ignores the top address byte passed to brk(), mmap() and mremap(). When the user is not aware of the 56-bit address limit or relies on the kernel to return an error, untagging such pointers has the potential to create address aliases in user-space. Passing a tagged address to munmap(), madvise() is permitted since the tagged pointer is expected to be inside an existing mapping. The current behaviour breaks the existing glibc malloc() implementation which relies on brk() with an address beyond 56-bit to be rejected by the kernel. Remove untagging in the above functions by partially reverting commit ce18d171cb ("mm: untag user pointers in mmap/munmap/mremap/brk"). In addition, update the arm64 tagged-address-abi.rst document accordingly. Link: https://bugzilla.redhat.com/1797052 Fixes: ce18d171cb ("mm: untag user pointers in mmap/munmap/mremap/brk") Cc: <stable@vger.kernel.org> # 5.4.x- Cc: Florian Weimer <fweimer@redhat.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reported-by: Victor Stinner <vstinner@redhat.com> Acked-by: Will Deacon <will@kernel.org> Acked-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2020-02-28 17:22:21 +01:00
..
acpi_object_usage.rst	docs: arm64: convert docs to ReST and rename to .rst	2019-06-14 14:20:27 -06:00
arm-acpi.rst	docs: arm64: convert docs to ReST and rename to .rst	2019-06-14 14:20:27 -06:00
booting.rst	Devicetree updates for v5.3:	2019-07-11 18:35:30 -07:00
cpu-feature-registers.rst	docs: arm64: convert docs to ReST and rename to .rst	2019-06-14 14:20:27 -06:00
elf_hwcaps.rst	It's been a relatively busy cycle for docs:	2019-07-09 12:34:26 -07:00
hugetlbpage.rst	docs: arm64: convert docs to ReST and rename to .rst	2019-06-14 14:20:27 -06:00
index.rst	arm64: Add tagged-address-abi.rst to index.rst	2019-08-22 18:22:57 +01:00
kasan-offsets.sh	arm64: kasan: Switch to using KASAN_SHADOW_OFFSET	2019-08-09 11:17:11 +01:00
legacy_instructions.rst	docs: arm64: convert docs to ReST and rename to .rst	2019-06-14 14:20:27 -06:00
memory.rst	docs: arm64: Fix indentation and doc formatting	2019-10-01 13:32:35 +01:00
perf.txt	arm64: docs: Document perf event attributes	2019-04-24 15:46:26 +01:00
pointer-authentication.rst	docs: arm64: convert docs to ReST and rename to .rst	2019-06-14 14:20:27 -06:00
silicon-errata.rst	arm64: apply ARM64_ERRATUM_843419 workaround for Brahma-B53 core	2019-11-01 10:47:37 +00:00
sve.rst	It's been a relatively busy cycle for docs:	2019-07-09 12:34:26 -07:00
tagged-address-abi.rst	mm: Avoid creating virtual address aliases in brk()/mmap()/mremap()	2020-02-28 17:22:21 +01:00
tagged-pointers.rst	arm64: Relax Documentation/arm64/tagged-pointers.rst	2019-08-27 18:16:20 +01:00