drivers/rapidio/rio_cm.c: prevent possible heap overwrite

commit 50695153d7ddde3b1696dbf0085be0033bf3ddb3 upstream.

In

riocm_cdev_ioctl(RIO_CM_CHAN_SEND)
   -> cm_chan_msg_send()
      -> riocm_ch_send()

cm_chan_msg_send() checks that userspace didn't send too much data but
riocm_ch_send() failed to check that userspace sent sufficient data.  The
result is that riocm_ch_send() can write to fields in the rio_ch_chan_hdr
which were outside the bounds of the space which cm_chan_msg_send()
allocated.

Address this by teaching riocm_ch_send() to check that the entire
rio_ch_chan_hdr was copied in from userspace.

Reported-by: maher azz <maherazz04@gmail.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Alexandre Bounine <alex.bou9@gmail.com>
Cc: Linus Torvalds <torvalds@linuxfoundation.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Andrew Morton
2025-06-07 17:43:18 -07:00
committed by Greg Kroah-Hartman
parent 675d90ee87
commit 1921781ec4

View File

@@ -787,6 +787,9 @@ static int riocm_ch_send(u16 ch_id, void *buf, int len)
if (buf == NULL || ch_id == 0 || len == 0 || len > RIO_MAX_MSG_SIZE) if (buf == NULL || ch_id == 0 || len == 0 || len > RIO_MAX_MSG_SIZE)
return -EINVAL; return -EINVAL;
if (len < sizeof(struct rio_ch_chan_hdr))
return -EINVAL; /* insufficient data from user */
ch = riocm_get_channel(ch_id); ch = riocm_get_channel(ch_id);
if (!ch) { if (!ch) {
riocm_error("%s(%d) ch_%d not found", current->comm, riocm_error("%s(%d) ch_%d not found", current->comm,