diff options
Diffstat (limited to 'kernel/user_namespace.c')
| -rw-r--r-- | kernel/user_namespace.c | 21 |
1 files changed, 7 insertions, 14 deletions
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index 88fefa68c516..9bafc211930c 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -602,8 +602,7 @@ static ssize_t map_write(struct file *file, const char __user *buf, struct uid_gid_map new_map; unsigned idx; struct uid_gid_extent *extent = NULL; - unsigned long page = 0; - char *kbuf, *pos, *next_line; + char *kbuf = NULL, *pos, *next_line; ssize_t ret = -EINVAL; /* @@ -638,23 +637,18 @@ static ssize_t map_write(struct file *file, const char __user *buf, if (cap_valid(cap_setid) && !file_ns_capable(file, ns, CAP_SYS_ADMIN)) goto out; - /* Get a buffer */ - ret = -ENOMEM; - page = __get_free_page(GFP_TEMPORARY); - kbuf = (char *) page; - if (!page) - goto out; - /* Only allow < page size writes at the beginning of the file */ ret = -EINVAL; if ((*ppos != 0) || (count >= PAGE_SIZE)) goto out; /* Slurp in the user data */ - ret = -EFAULT; - if (copy_from_user(kbuf, buf, count)) + kbuf = memdup_user_nul(buf, count); + if (IS_ERR(kbuf)) { + ret = PTR_ERR(kbuf); + kbuf = NULL; goto out; - kbuf[count] = '\0'; + } /* Parse the user data */ ret = -EINVAL; @@ -756,8 +750,7 @@ static ssize_t map_write(struct file *file, const char __user *buf, ret = count; out: mutex_unlock(&userns_state_mutex); - if (page) - free_page(page); + kfree(kbuf); return ret; } |