diff --git a/[refs] b/[refs] index 76d577690c25..dd99959e688c 100644 --- a/[refs] +++ b/[refs] @@ -1,2 +1,2 @@ --- -refs/heads/master: 35f349ee082de0be45eb23926d9fc7569f5011f0 +refs/heads/master: de9e007d9105bf8fa613a89810feff32a43add03 diff --git a/trunk/kernel/sysctl.c b/trunk/kernel/sysctl.c index e5102ea6e104..b53115b882e1 100644 --- a/trunk/kernel/sysctl.c +++ b/trunk/kernel/sysctl.c @@ -2192,27 +2192,32 @@ int sysctl_string(ctl_table *table, int __user *name, int nlen, void __user *oldval, size_t __user *oldlenp, void __user *newval, size_t newlen, void **context) { - size_t l, len; - if (!table->data || !table->maxlen) return -ENOTDIR; if (oldval && oldlenp) { - if (get_user(len, oldlenp)) + size_t bufsize; + if (get_user(bufsize, oldlenp)) return -EFAULT; - if (len) { - l = strlen(table->data)+1; - if (len > l) len = l; - if (len >= table->maxlen) + if (bufsize) { + size_t len = strlen(table->data), copied; + + /* This shouldn't trigger for a well-formed sysctl */ + if (len > table->maxlen) len = table->maxlen; - if(copy_to_user(oldval, table->data, len)) + + /* Copy up to a max of bufsize-1 bytes of the string */ + copied = (len >= bufsize) ? bufsize - 1 : len; + + if (copy_to_user(oldval, table->data, copied) || + put_user(0, (char __user *)(oldval + copied))) return -EFAULT; - if(put_user(len, oldlenp)) + if (put_user(len, oldlenp)) return -EFAULT; } } if (newval && newlen) { - len = newlen; + size_t len = newlen; if (len > table->maxlen) len = table->maxlen; if(copy_from_user(table->data, newval, len))