diff options
| author | Ben Hutchings <ben.hutchings@codethink.co.uk> | 2018-08-15 21:44:25 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-09-26 08:36:37 +0200 |
| commit | 71d2d4790cbd4052d5f7f504d347088d9c242a4b (patch) | |
| tree | ff1d0a408bf4ec24c9517ff2f8d1f4b9797273d1 | |
| parent | cd3005db7518d05e2e7b55fbcbe5ce6966db5ace (diff) | |
USB: yurex: Fix buffer over-read in yurex_write()
commit 7e10f14ebface44a48275c8d6dc1caae3668d5a9 upstream.
If the written data starts with a digit, yurex_write() tries to parse
it as an integer using simple_strtoull(). This requires a null-
terminator, and currently there's no guarantee that there is one.
(The sample program at
https://github.com/NeoCat/YUREX-driver-for-Linux/blob/master/sample/yurex_clock.pl
writes an integer without a null terminator. It seems like it must
have worked by chance!)
Always add a null byte after the written data. Enlarge the buffer
to allow for this.
Cc: stable@vger.kernel.org
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/usb/misc/yurex.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/usb/misc/yurex.c b/drivers/usb/misc/yurex.c index f36968ee2e70..e36c6c6452cd 100644 --- a/drivers/usb/misc/yurex.c +++ b/drivers/usb/misc/yurex.c @@ -431,13 +431,13 @@ static ssize_t yurex_write(struct file *file, const char __user *user_buffer, { struct usb_yurex *dev; int i, set = 0, retval = 0; - char buffer[16]; + char buffer[16 + 1]; char *data = buffer; unsigned long long c, c2 = 0; signed long timeout = 0; DEFINE_WAIT(wait); - count = min(sizeof(buffer), count); + count = min(sizeof(buffer) - 1, count); dev = file->private_data; /* verify that we actually have some data to write */ @@ -456,6 +456,7 @@ static ssize_t yurex_write(struct file *file, const char __user *user_buffer, retval = -EFAULT; goto error; } + buffer[count] = 0; memset(dev->cntl_buffer, CMD_PADDING, YUREX_BUF_SIZE); switch (buffer[0]) { |