Do not use RCU for current process credentials
Commit c69e8d9c0 added rcu lock to fuse/dir.c It was assuming
that 'task' is some other process but in fact this parameter always
equals to 'current'. Inline this parameter to make it more readable
and remove RCU lock as it is not needed when access current process
credentials.
Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index ed8f8c5..aa0b6ad 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -985,7 +985,7 @@
/*
* Calling into a user-controlled filesystem gives the filesystem
- * daemon ptrace-like capabilities over the requester process. This
+ * daemon ptrace-like capabilities over the current process. This
* means, that the filesystem daemon is able to record the exact
* filesystem operations performed, and can also control the behavior
* of the requester process in otherwise impossible ways. For example
@@ -996,27 +996,23 @@
* for which the owner of the mount has ptrace privilege. This
* excludes processes started by other users, suid or sgid processes.
*/
-int fuse_allow_task(struct fuse_conn *fc, struct task_struct *task)
+int fuse_allow_current_process(struct fuse_conn *fc)
{
const struct cred *cred;
- int ret;
if (fc->flags & FUSE_ALLOW_OTHER)
return 1;
- rcu_read_lock();
- ret = 0;
- cred = __task_cred(task);
+ cred = current_cred();
if (uid_eq(cred->euid, fc->user_id) &&
uid_eq(cred->suid, fc->user_id) &&
uid_eq(cred->uid, fc->user_id) &&
gid_eq(cred->egid, fc->group_id) &&
gid_eq(cred->sgid, fc->group_id) &&
gid_eq(cred->gid, fc->group_id))
- ret = 1;
- rcu_read_unlock();
+ return 1;
- return ret;
+ return 0;
}
static int fuse_access(struct inode *inode, int mask)
@@ -1077,7 +1073,7 @@
bool refreshed = false;
int err = 0;
- if (!fuse_allow_task(fc, current))
+ if (!fuse_allow_current_process(fc))
return -EACCES;
/*
@@ -1544,7 +1540,7 @@
loff_t oldsize;
int err;
- if (!fuse_allow_task(fc, current))
+ if (!fuse_allow_current_process(fc))
return -EACCES;
if (!(fc->flags & FUSE_DEFAULT_PERMISSIONS))
@@ -1653,7 +1649,7 @@
struct inode *inode = entry->d_inode;
struct fuse_conn *fc = get_fuse_conn(inode);
- if (!fuse_allow_task(fc, current))
+ if (!fuse_allow_current_process(fc))
return -EACCES;
return fuse_update_attributes(inode, stat, NULL, NULL);
@@ -1756,7 +1752,7 @@
struct fuse_getxattr_out outarg;
ssize_t ret;
- if (!fuse_allow_task(fc, current))
+ if (!fuse_allow_current_process(fc))
return -EACCES;
if (fc->no_listxattr)