linux-ext4 - [PATCH 3/8] fuse2fs: better debugging for file mode updates

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <175573714446.22854.17340819202248729756.stgit@frogsfrogsfrogs>
Date: Wed, 20 Aug 2025 18:21:57 -0700
From: "Darrick J. Wong" <djwong@...nel.org>
To: tytso@....edu
Cc: John@...ves.net, bernd@...ernd.com, linux-fsdevel@...r.kernel.org,
 linux-ext4@...r.kernel.org, miklos@...redi.hu, joannelkoong@...il.com,
 neal@...pa.dev
Subject: [PATCH 3/8] fuse2fs: better debugging for file mode updates

From: Darrick J. Wong <djwong@...nel.org>

Improve the tracing of a chmod operation so that we can debug file mode
updates.

Signed-off-by: "Darrick J. Wong" <djwong@...nel.org>
---
 misc/fuse2fs.c |   12 +++++++-----
 misc/fuse4fs.c |   10 ++++++----
 2 files changed, 13 insertions(+), 9 deletions(-)


diff --git a/misc/fuse2fs.c b/misc/fuse2fs.c
index 11ddf6a4001955..44f76e9bed5f42 100644
--- a/misc/fuse2fs.c
+++ b/misc/fuse2fs.c
@@ -3195,6 +3195,7 @@ static int op_chmod(const char *path, mode_t mode
 	errcode_t err;
 	ext2_ino_t ino;
 	struct ext2_inode_large inode;
+	mode_t new_mode;
 	int ret = 0;
 
 	FUSE2FS_CHECK_CONTEXT(ff);
@@ -3233,11 +3234,12 @@ static int op_chmod(const char *path, mode_t mode
 			mode &= ~S_ISGID;
 	}
 
-	inode.i_mode &= ~0xFFF;
-	inode.i_mode |= mode & 0xFFF;
+	new_mode = (inode.i_mode & ~0xFFF) | (mode & 0xFFF);
 
-	dbg_printf(ff, "%s: path=%s new_mode=0%o ino=%d\n", __func__,
-		   path, inode.i_mode, ino);
+	dbg_printf(ff, "%s: path=%s old_mode=0%o new_mode=0%o ino=%d\n",
+		   __func__, path, inode.i_mode, new_mode, ino);
+
+	inode.i_mode = new_mode;
 
 	ret = update_ctime(fs, ino, &inode);
 	if (ret)
@@ -3260,12 +3262,12 @@ static int op_chown(const char *path, uid_t owner, gid_t group
 #endif
 			)
 {
+	struct ext2_inode_large inode;
 	struct fuse_context *ctxt = fuse_get_context();
 	struct fuse2fs *ff = fuse2fs_get();
 	ext2_filsys fs;
 	errcode_t err;
 	ext2_ino_t ino;
-	struct ext2_inode_large inode;
 	int ret = 0;
 
 	FUSE2FS_CHECK_CONTEXT(ff);
diff --git a/misc/fuse4fs.c b/misc/fuse4fs.c
index ef6f3b33db99fd..b68573f654279d 100644
--- a/misc/fuse4fs.c
+++ b/misc/fuse4fs.c
@@ -3463,6 +3463,7 @@ static int fuse4fs_chmod(struct fuse4fs *ff, fuse_req_t req, ext2_ino_t ino,
 			 mode_t mode, struct ext2_inode_large *inode)
 {
 	const struct fuse_ctx *ctxt = fuse_req_ctx(req);
+	mode_t new_mode;
 	int ret = 0;
 
 	dbg_printf(ff, "%s: ino=%d mode=0%o\n", __func__, ino, mode);
@@ -3489,11 +3490,12 @@ static int fuse4fs_chmod(struct fuse4fs *ff, fuse_req_t req, ext2_ino_t ino,
 			mode &= ~S_ISGID;
 	}
 
-	inode->i_mode &= ~0xFFF;
-	inode->i_mode |= mode & 0xFFF;
+	new_mode = (inode->i_mode & ~0xFFF) | (mode & 0xFFF);
 
-	dbg_printf(ff, "%s: ino=%d new_mode=0%o\n",
-		   __func__, ino, inode->i_mode);
+	dbg_printf(ff, "%s: ino=%d old_mode=0%o new_mode=0%o\n",
+		   __func__, ino, inode->i_mode, new_mode);
+
+	inode->i_mode = new_mode;
 
 	return 0;
 }