+ mm-gup_test-reject-wrapped-user-ranges.patch added to mm-nonmm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm/gup_test: reject wrapped user ranges
has been added to the -mm mm-nonmm-unstable branch.  Its filename is
     mm-gup_test-reject-wrapped-user-ranges.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-gup_test-reject-wrapped-user-ranges.patch

This patch will later appear in the mm-nonmm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Samuel Moelius <sam.moelius@trailofbits.com>
Subject: mm/gup_test: reject wrapped user ranges
Date: Tue, 9 Jun 2026 00:48:15 +0000

gup_test accepts an address and size from the debugfs ioctl and repeatedly
compares against addr + size.  If that addition wraps, the loop can be
skipped and the ioctl returns success with size rewritten to zero.

Compute the end address once with overflow checking and use that checked
end for the loop bounds.

Assisted-by: Codex:gpt-5.5-cyber-preview
Link: https://lore.kernel.org/20260609004814.1240586.6294d614ac80.gup-test-range-end-wrap@trailofbits.com
Signed-off-by: Samuel Moelius <sam.moelius@trailofbits.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Peter Xu <peterx@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/gup_test.c |   12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

--- a/mm/gup_test.c~mm-gup_test-reject-wrapped-user-ranges
+++ a/mm/gup_test.c
@@ -105,11 +105,15 @@ static int __gup_test_ioctl(unsigned int
 	unsigned long i, nr_pages, addr, next;
 	long nr;
 	struct page **pages;
+	unsigned long end;
 	int ret = 0;
 	bool needs_mmap_lock =
 		cmd != GUP_FAST_BENCHMARK && cmd != PIN_FAST_BENCHMARK;
 
-	if (gup->size > ULONG_MAX)
+	if (gup->addr > ULONG_MAX || gup->size > ULONG_MAX)
+		return -EINVAL;
+	if (check_add_overflow((unsigned long)gup->addr,
+			       (unsigned long)gup->size, &end))
 		return -EINVAL;
 
 	nr_pages = gup->size / PAGE_SIZE;
@@ -125,13 +129,13 @@ static int __gup_test_ioctl(unsigned int
 	i = 0;
 	nr = gup->nr_pages_per_call;
 	start_time = ktime_get();
-	for (addr = gup->addr; addr < gup->addr + gup->size; addr = next) {
+	for (addr = gup->addr; addr < end; addr = next) {
 		if (nr != gup->nr_pages_per_call)
 			break;
 
 		next = addr + nr * PAGE_SIZE;
-		if (next > gup->addr + gup->size) {
-			next = gup->addr + gup->size;
+		if (next > end) {
+			next = end;
 			nr = (next - addr) / PAGE_SIZE;
 		}
 
_

Patches currently in -mm which might be from sam.moelius@trailofbits.com are

mm-page_frag-reject-invalid-cpus-in-page_frag_test.patch
lib-test_firmware-allocate-the-configured-into_buf-size.patch
lib-interval_tree_test-validate-benchmark-parameters.patch
mm-gup_test-reject-wrapped-user-ranges.patch