diff options
| author | Heinrich Schuchardt <xypron.glpk@gmx.de> | 2015-04-28 19:30:47 +0200 |
|---|---|---|
| committer | Peter Chen <peter.chen@freescale.com> | 2015-05-06 08:28:18 +0200 |
| commit | bd5fb0aec3dd7cde7ec4c397b10e55d4c9626d8d (patch) | |
| tree | 207a768da295aac03cdfe4db7bbab0f3f97ea772 | |
| parent | cdc-acm: prevent infinite loop when parsing CDC headers. (diff) | |
| download | linux-bd5fb0aec3dd7cde7ec4c397b10e55d4c9626d8d.tar.xz linux-bd5fb0aec3dd7cde7ec4c397b10e55d4c9626d8d.zip | |
usb: chipidea: debug: avoid out of bound read
A string written by the user may not be zero terminated.
sscanf may read memory beyond the buffer if no zero byte
is found.
For testing build with CONFIG_USB_CHIPIDEA=y, CONFIG_USB_CHIPIDEA_DEBUG=y.
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Peter Chen <peter.chen@freescale.com>
| -rw-r--r-- | drivers/usb/chipidea/debug.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/usb/chipidea/debug.c b/drivers/usb/chipidea/debug.c index dfb05edcdb96..5b7061a33103 100644 --- a/drivers/usb/chipidea/debug.c +++ b/drivers/usb/chipidea/debug.c @@ -88,9 +88,13 @@ static ssize_t ci_port_test_write(struct file *file, const char __user *ubuf, char buf[32]; int ret; - if (copy_from_user(buf, ubuf, min_t(size_t, sizeof(buf) - 1, count))) + count = min_t(size_t, sizeof(buf) - 1, count); + if (copy_from_user(buf, ubuf, count)) return -EFAULT; + /* sscanf requires a zero terminated string */ + buf[count] = '\0'; + if (sscanf(buf, "%u", &mode) != 1) return -EINVAL; |