From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Date: Tue, 12 Aug 2025 15:17:44 +0000 (+0900)
Subject: minixfs: Verify inode mode when loading from disk
X-Git-Tag: v5.4.301~81
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=6b9f2563bdc9ef05240ee1d92ae4f303a39d5968;p=thirdparty%2Fkernel%2Fstable.git

minixfs: Verify inode mode when loading from disk

[ Upstream commit 73861970938ad1323eb02bbbc87f6fbd1e5bacca ]

The inode mode loaded from corrupted disk can be invalid. Do like what
commit 0a9e74051313 ("isofs: Verify inode mode when loading from disk")
does.

Reported-by: syzbot <syzbot+895c23f6917da440ed0d@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=895c23f6917da440ed0d
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Link: https://lore.kernel.org/ec982681-84b8-4624-94fa-8af15b77cbd2@I-love.SAKURA.ne.jp
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/fs/minix/inode.c b/fs/minix/inode.c
index 3fffc709afd43..c026706aec0cc 100644
--- a/fs/minix/inode.c
+++ b/fs/minix/inode.c
@@ -470,8 +470,14 @@ void minix_set_inode(struct inode *inode, dev_t rdev)
 		inode->i_op = &minix_symlink_inode_operations;
 		inode_nohighmem(inode);
 		inode->i_mapping->a_ops = &minix_aops;
-	} else
+	} else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
+		   S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
 		init_special_inode(inode, inode->i_mode, rdev);
+	} else {
+		printk(KERN_DEBUG "MINIX-fs: Invalid file type 0%04o for inode %lu.\n",
+		       inode->i_mode, inode->i_ino);
+		make_bad_inode(inode);
+	}
 }
 
 /*