Re: [PATCH V36 27/29] tracefs: Restrict tracefs when the kernel is locked down
From: Steven Rostedt <rostedt@goodmis.org>
Date: 2019-07-25 02:23:59
Also in:
linux-api, lkml
On Thu, 18 Jul 2019 12:44:13 -0700 Matthew Garrett [off-list ref] wrote:
quoted hunk ↗ jump to hunk
@@ -387,6 +412,7 @@ struct dentry *tracefs_create_file(const char *name, umode_t mode, struct dentry *parent, void *data, const struct file_operations *fops) { + struct file_operations *proxy_fops; struct dentry *dentry; struct inode *inode;@@ -402,8 +428,18 @@ struct dentry *tracefs_create_file(const char *name, umode_t mode, if (unlikely(!inode)) return failed_creating(dentry); + proxy_fops = kzalloc(sizeof(struct file_operations), GFP_KERNEL); + if (!proxy_fops)
I believe we need "iput(inode);" here. Or move the allocation before the inode allocation and free it on inode failure. -- Steve
+ return failed_creating(dentry); + + if (!fops) + fops = &tracefs_file_operations; + + dentry->d_fsdata = (void *)fops; + memcpy(proxy_fops, fops, sizeof(*proxy_fops)); + proxy_fops->open = default_open_file; inode->i_mode = mode; - inode->i_fop = fops ? fops : &tracefs_file_operations; + inode->i_fop = proxy_fops; inode->i_private = data; d_instantiate(dentry, inode); fsnotify_create(dentry->d_parent->d_inode, dentry);