From 8febdd85adaa41fa1fc1cb31286210fc2cd3ed0c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Fri, 30 Dec 2005 17:18:53 -0800 Subject: [PATCH] sysctl: don't overflow the user-supplied buffer with '\0' If the string was too long to fit in the user-supplied buffer, the sysctl layer would zero-terminate it by writing past the end of the buffer. Don't do that. Noticed by Yi Yang Signed-off-by: Linus Torvalds --- kernel/sysctl.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 9990e10192..ad0425a8f7 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -2201,14 +2201,12 @@ int sysctl_string(ctl_table *table, int __user *name, int nlen, if (get_user(len, oldlenp)) return -EFAULT; if (len) { - l = strlen(table->data); + l = strlen(table->data)+1; if (len > l) len = l; if (len >= table->maxlen) len = table->maxlen; if(copy_to_user(oldval, table->data, len)) return -EFAULT; - if(put_user(0, ((char __user *) oldval) + len)) - return -EFAULT; if(put_user(len, oldlenp)) return -EFAULT; } -- 2.39.5