vfs: catch invalid modes in may_open()

mjguzik · brauner · commit af153bb63a33 · 2025-02-21T10:23:53.000+01:00
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com> Link: https://lore.kernel.org/r/20250209185523.745956-3-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
@@ -3415,6 +3415,8 @@ static int may_open(struct mnt_idmap *idmap, const struct path *path,
 		if ((acc_mode & MAY_EXEC) && path_noexec(path))
 			return -EACCES;
 		break;
+	default:
+		VFS_BUG_ON_INODE(1, inode);
 	}
 
 	error = inode_permission(idmap, inode, MAY_OPEN | acc_mode);

Original file line number	Diff line number	Diff line change
`@@ -3415,6 +3415,8 @@ static int may_open(struct mnt_idmap idmap, const struct path path,`
`3415`	`3415`	`if ((acc_mode & MAY_EXEC) && path_noexec(path))`
`3416`	`3416`	`return -EACCES;`
`3417`	`3417`	`break;`
	`3418`	`+ default:`
	`3419`	`+ VFS_BUG_ON_INODE(1, inode);`
`3418`	`3420`	`}`
`3419`	`3421`
`3420`	`3422`	`error = inode_permission(idmap, inode, MAY_OPEN \| acc_mode);`