From: Mateusz Guzik <mjguzik@gmail.com>
Date: Tue, 4 Jun 2024 15:52:57 +0000 (+0200)
Subject: vfs: shave a branch in getname_flags
X-Git-Tag: v6.11-rc1~242^2~15
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d4f50ea957cab6ea940cc072a142b1e964a10ee6;p=thirdparty%2Fkernel%2Flinux.git

vfs: shave a branch in getname_flags

Check for an error while copying and no path in one branch.

Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Link: https://lore.kernel.org/r/20240604155257.109500-4-mjguzik@gmail.com
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
---

diff --git a/fs/namei.c b/fs/namei.c
index 950ad6bdd9feb..3d3674c21d3c4 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -148,9 +148,20 @@ getname_flags(const char __user *filename, int flags)
 	result->name = kname;
 
 	len = strncpy_from_user(kname, filename, EMBEDDED_NAME_MAX);
-	if (unlikely(len < 0)) {
-		__putname(result);
-		return ERR_PTR(len);
+	/*
+	 * Handle both empty path and copy failure in one go.
+	 */
+	if (unlikely(len <= 0)) {
+		if (unlikely(len < 0)) {
+			__putname(result);
+			return ERR_PTR(len);
+		}
+
+		/* The empty path is special. */
+		if (!(flags & LOOKUP_EMPTY)) {
+			__putname(result);
+			return ERR_PTR(-ENOENT);
+		}
 	}
 
 	/*
@@ -180,6 +191,12 @@ getname_flags(const char __user *filename, int flags)
 			kfree(result);
 			return ERR_PTR(len);
 		}
+		/* The empty path is special. */
+		if (unlikely(!len) && !(flags & LOOKUP_EMPTY)) {
+			__putname(kname);
+			kfree(result);
+			return ERR_PTR(-ENOENT);
+		}
 		if (unlikely(len == PATH_MAX)) {
 			__putname(kname);
 			kfree(result);
@@ -188,14 +205,6 @@ getname_flags(const char __user *filename, int flags)
 	}
 
 	atomic_set(&result->refcnt, 1);
-	/* The empty path is special. */
-	if (unlikely(!len)) {
-		if (!(flags & LOOKUP_EMPTY)) {
-			putname(result);
-			return ERR_PTR(-ENOENT);
-		}
-	}
-
 	result->uptr = filename;
 	result->aname = NULL;
 	audit_getname(result);