linux-kernel - [PATCH v2] fs: Fix uninitialized value issue in from_kuid and from

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-next>] [day] [month] [year] [list]

Message-ID: <20241017120553.55331-1-alessandro.zanni87@gmail.com>
Date: Thu, 17 Oct 2024 14:05:51 +0200
From: Alessandro Zanni <alessandro.zanni87@...il.com>
To: viro@...iv.linux.org.uk,
	brauner@...nel.org,
	jack@...e.cz
Cc: Alessandro Zanni <alessandro.zanni87@...il.com>,
	linux-fsdevel@...r.kernel.org,
	linux-kernel@...r.kernel.org,
	skhan@...uxfoundation.org,
	anupnewsmail@...il.com,
	alessandrozanni.dev@...il.com,
	syzbot+6c55f725d1bdc8c52058@...kaller.appspotmail.com
Subject: [PATCH v2] fs: Fix uninitialized value issue in from_kuid and from_kgid

ocfs2_setattr() uses attr->ia_mode, attr->ia_uid and attr->ia_gid in
a trace point even though ATTR_MODE, ATTR_UID and ATTR_GID aren't set.

Initialize all fields of newattrs to avoid uninitialized variables, by
checking if ATTR_MODE, ATTR_UID, ATTR_GID are initialized, otherwise 0.

Reported-by: syzbot+6c55f725d1bdc8c52058@...kaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=6c55f725d1bdc8c52058
Signed-off-by: Alessandro Zanni <alessandro.zanni87@...il.com>
---

Notes:
    v2: fix ocfs2_setattr to avoid similar issues; improved commit description

 fs/ocfs2/file.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index ad131a2fc58e..58887456e3c5 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -1129,9 +1129,12 @@ int ocfs2_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 	trace_ocfs2_setattr(inode, dentry,
 			    (unsigned long long)OCFS2_I(inode)->ip_blkno,
 			    dentry->d_name.len, dentry->d_name.name,
-			    attr->ia_valid, attr->ia_mode,
-			    from_kuid(&init_user_ns, attr->ia_uid),
-			    from_kgid(&init_user_ns, attr->ia_gid));
+			    attr->ia_valid,
+				attr->ia_valid & ATTR_MODE ? attr->ia_mode : 0,
+				attr->ia_valid & ATTR_UID ?
+					from_kuid(&init_user_ns, attr->ia_uid) : 0,
+				attr->ia_valid & ATTR_GID ?
+					from_kgid(&init_user_ns, attr->ia_gid) : 0);
 
 	/* ensuring we don't even attempt to truncate a symlink */
 	if (S_ISLNK(inode->i_mode))
-- 
2.43.0