From 13daec4d7036419a94790ecd8ca478efdb7f14f1 Mon Sep 17 00:00:00 2001
From: Catalin Marinas <catalin.marinas@arm.com>
Date: Wed, 25 Sep 2019 16:49:04 -0700
Subject: [PATCH] UPSTREAM: mm: untag user pointers in mmap/munmap/mremap/brk

(Upstream commit ce18d171cb7368557e6498a3ce111d7d3dc03e4d).

There isn't a good reason to differentiate between the user address space
layout modification syscalls and the other memory permission/attributes
ones (e.g.  mprotect, madvise) w.r.t.  the tagged address ABI.  Untag the
user addresses on entry to these functions.

Link: http://lkml.kernel.org/r/20190821164730.47450-2-catalin.marinas@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Szabolcs Nagy <szabolcs.nagy@arm.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Dave P Martin <Dave.Martin@arm.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Bug: 135692346
Change-Id: If6a7be6d5f39f411bd65c49100088d0ceae530ee
---
 mm/mmap.c   | 5 +++++
 mm/mremap.c | 6 +-----
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/mm/mmap.c b/mm/mmap.c
index 3cc7a94a5422..44cc476794de 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -199,6 +199,8 @@ SYSCALL_DEFINE1(brk, unsigned long, brk)
 	bool populate;
 	LIST_HEAD(uf);
 
+	brk = untagged_addr(brk);
+
 	if (down_write_killable(&mm->mmap_sem))
 		return -EINTR;
 
@@ -1557,6 +1559,8 @@ unsigned long ksys_mmap_pgoff(unsigned long addr, unsigned long len,
 	struct file *file = NULL;
 	unsigned long retval;
 
+	addr = untagged_addr(addr);
+
 	if (!(flags & MAP_ANONYMOUS)) {
 		audit_mmap_fd(fd, flags);
 		file = fget(fd);
@@ -2819,6 +2823,7 @@ EXPORT_SYMBOL(vm_munmap);
 
 SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len)
 {
+	addr = untagged_addr(addr);
 	profile_munmap(addr);
 	return vm_munmap(addr, len);
 }
diff --git a/mm/mremap.c b/mm/mremap.c
index 1b5baa7b9a64..3c0bcf65fd46 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -525,12 +525,8 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
 	LIST_HEAD(uf_unmap_early);
 	LIST_HEAD(uf_unmap);
 
-	/*
-	 * Architectures may interpret the tag passed to mmap as a background
-	 * colour for the corresponding vma. For mremap we don't allow tagged
-	 * new_addr to preserve similar behaviour to mmap.
-	 */
 	addr = untagged_addr(addr);
+	new_addr = untagged_addr(new_addr);
 
 	if (flags & ~(MREMAP_FIXED | MREMAP_MAYMOVE))
 		return ret;