diff options
| -rw-r--r-- | lib/dynamic_debug.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index 86a9abb9a1ce..d8773dcd83c5 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -570,24 +570,32 @@ __setup("ddebug_query=", ddebug_setup_query); * File_ops->write method for <debugfs>/dynamic_debug/conrol. Gathers the * command text from userspace, parses and executes it. */ +#define USER_BUF_PAGE 4096 static ssize_t ddebug_proc_write(struct file *file, const char __user *ubuf, size_t len, loff_t *offp) { - char tmpbuf[256]; + char *tmpbuf; int ret; if (len == 0) return 0; - /* we don't check *offp -- multiple writes() are allowed */ - if (len > sizeof(tmpbuf)-1) + if (len > USER_BUF_PAGE - 1) { + pr_warn("expected <%d bytes into control\n", USER_BUF_PAGE); return -E2BIG; - if (copy_from_user(tmpbuf, ubuf, len)) + } + tmpbuf = kmalloc(len + 1, GFP_KERNEL); + if (!tmpbuf) + return -ENOMEM; + if (copy_from_user(tmpbuf, ubuf, len)) { + kfree(tmpbuf); return -EFAULT; + } tmpbuf[len] = '\0'; if (verbose) pr_info("read %d bytes from userspace\n", (int)len); ret = ddebug_exec_query(tmpbuf); + kfree(tmpbuf); if (ret) return ret; |