This is a note to let you know that I've just added the patch titled
net: macb: Add a NULL check on desc_ptp
to the 5.13-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-macb-add-a-null-check-on-desc_ptp.patch
and it can be found in the queue-5.13 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 7e613b84acdcecba22d540f375065f02f1d5bfec
Author: Harini Katakam <harini.katakam@xxxxxxxxxx>
Date: Tue Aug 24 15:32:09 2021 +0530
net: macb: Add a NULL check on desc_ptp
[ Upstream commit 85520079afce885b80647fbd0d13d8f03d057167 ]
macb_ptp_desc will not return NULL under most circumstances with correct
Kconfig and IP design config register. But for the sake of the extreme
corner case, check for NULL when using the helper. In case of rx_tstamp,
no action is necessary except to return (similar to timestamp disabled)
and warn. In case of TX, return -EINVAL to let the skb be free. Perform
this check before marking skb in progress.
Fixes coverity warning:
(4) Event dereference:
Dereferencing a null pointer "desc_ptp"
Signed-off-by: Harini Katakam <harini.katakam@xxxxxxxxxx>
Reviewed-by: Radhey Shyam Pandey <radhey.shyam.pandey@xxxxxxxxxx>
Signed-off-by: Michal Simek <michal.simek@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/ethernet/cadence/macb_ptp.c b/drivers/net/ethernet/cadence/macb_ptp.c
index 283918aeb741..09d64a29f56e 100644
--- a/drivers/net/ethernet/cadence/macb_ptp.c
+++ b/drivers/net/ethernet/cadence/macb_ptp.c
@@ -275,6 +275,12 @@ void gem_ptp_rxstamp(struct macb *bp, struct sk_buff *skb,
if (GEM_BFEXT(DMA_RXVALID, desc->addr)) {
desc_ptp = macb_ptp_desc(bp, desc);
+ /* Unlikely but check */
+ if (!desc_ptp) {
+ dev_warn_ratelimited(&bp->pdev->dev,
+ "Timestamp not supported in BD\n");
+ return;
+ }
gem_hw_timestamp(bp, desc_ptp->ts_1, desc_ptp->ts_2, &ts);
memset(shhwtstamps, 0, sizeof(struct skb_shared_hwtstamps));
shhwtstamps->hwtstamp = ktime_set(ts.tv_sec, ts.tv_nsec);
@@ -307,8 +313,11 @@ int gem_ptp_txstamp(struct macb_queue *queue, struct sk_buff *skb,
if (CIRC_SPACE(head, tail, PTP_TS_BUFFER_SIZE) == 0)
return -ENOMEM;
- skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
desc_ptp = macb_ptp_desc(queue->bp, desc);
+ /* Unlikely but check */
+ if (!desc_ptp)
+ return -EINVAL;
+ skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
tx_timestamp = &queue->tx_timestamps[head];
tx_timestamp->skb = skb;
/* ensure ts_1/ts_2 is loaded after ctrl (TX_USED check) */
