From 50695153d7ddde3b1696dbf0085be0033bf3ddb3 Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Sat, 7 Jun 2025 17:43:18 -0700 Subject: [PATCH] drivers/rapidio/rio_cm.c: prevent possible heap overwrite 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 Cc: Matt Porter Cc: Alexandre Bounine Cc: Linus Torvalds Cc: Signed-off-by: Andrew Morton --- drivers/rapidio/rio_cm.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/rapidio/rio_cm.c b/drivers/rapidio/rio_cm.c index 97287e838ce16..66464674223fb 100644 --- a/drivers/rapidio/rio_cm.c +++ b/drivers/rapidio/rio_cm.c @@ -783,6 +783,9 @@ 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) return -EINVAL; + if (len < sizeof(struct rio_ch_chan_hdr)) + return -EINVAL; /* insufficient data from user */ + ch = riocm_get_channel(ch_id); if (!ch) { riocm_error("%s(%d) ch_%d not found", current->comm, -- 2.39.5