From: Hao Ge <hao.ge@linux.dev>
Date: Thu, 28 May 2026 01:13:36 +0000 (+0800)
Subject: lib/test_hmm: fix memory leak in dmirror_migrate_to_system()
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=8f7275c174bc5bcc8fc1bec8024e2b3e6fe17f46;p=thirdparty%2Fkernel%2Flinux.git

lib/test_hmm: fix memory leak in dmirror_migrate_to_system()

Move the kvcalloc() calls after the early return checks to avoid leaking
src_pfns and dst_pfns when end < start or mmget_not_zero() fails.

Link: https://lore.kernel.org/20260528011336.20797-1-hao.ge@linux.dev
Fixes: 775465fd26a3 ("lib/test_hmm: add zone device private THP test infrastructure")
Signed-off-by: Hao Ge <hao.ge@linux.dev>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Reported-by: Sashiko <sashiko-bot@kernel.org>
Reviewed-by: Balbir Singh <balbirs@nvidia.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

diff --git a/lib/test_hmm.c b/lib/test_hmm.c
index 63bf77dee987..35f774ed2d99 100644
--- a/lib/test_hmm.c
+++ b/lib/test_hmm.c
@@ -1111,9 +1111,6 @@ static int dmirror_migrate_to_system(struct dmirror *dmirror,
 	unsigned long *src_pfns;
 	unsigned long *dst_pfns;
 
-	src_pfns = kvcalloc(PTRS_PER_PTE, sizeof(*src_pfns), GFP_KERNEL | __GFP_NOFAIL);
-	dst_pfns = kvcalloc(PTRS_PER_PTE, sizeof(*dst_pfns), GFP_KERNEL | __GFP_NOFAIL);
-
 	start = cmd->addr;
 	end = start + size;
 	if (end < start)
@@ -1123,6 +1120,9 @@ static int dmirror_migrate_to_system(struct dmirror *dmirror,
 	if (!mmget_not_zero(mm))
 		return -EINVAL;
 
+	src_pfns = kvcalloc(PTRS_PER_PTE, sizeof(*src_pfns), GFP_KERNEL | __GFP_NOFAIL);
+	dst_pfns = kvcalloc(PTRS_PER_PTE, sizeof(*dst_pfns), GFP_KERNEL | __GFP_NOFAIL);
+
 	cmd->cpages = 0;
 	mmap_read_lock(mm);
 	for (addr = start; addr < end; addr = next) {