[PATCH] mm/madvise: retrieve mm before checking

[Lorenzo Stoakes]

---
 mm/madvise.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/mm/madvise.c b/mm/madvise.c
index 549b36d1463c..49d12f98b677 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -1535,20 +1535,20 @@ SYSCALL_DEFINE5(process_madvise, int, pidfd, const struct iovec __user *, vec,
 		goto free_iov;
 	}

+	/* Require PTRACE_MODE_READ to avoid leaking ASLR metadata. */
+	mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
+	if (IS_ERR_OR_NULL(mm)) {
+		ret = IS_ERR(mm) ? PTR_ERR(mm) : -ESRCH;
+		goto release_task;
+	}
+
 	/*
 	 * We need only perform this check if we are attempting to manipulate a
 	 * remote process's address space.
 	 */
 	if (mm != current->mm && !process_madvise_remote_valid(behavior)) {
 		ret = -EINVAL;
-		goto release_task;
-	}
-
-	/* Require PTRACE_MODE_READ to avoid leaking ASLR metadata. */
-	mm = mm_access(task, PTRACE_MODE_READ_FSCREDS);
-	if (IS_ERR_OR_NULL(mm)) {
-		ret = IS_ERR(mm) ? PTR_ERR(mm) : -ESRCH;
-		goto release_task;
+		goto release_mm;
 	}

 	/*
--
2.46.0