This is a note to let you know that I've just added the patch titled
nfc: pn533: Fix double free when pn533_fill_fragment_skbs() fails
to the 4.4-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:
nfc-pn533-fix-double-free-when-pn533_fill_fragment_s.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit f2037bedea0ecf45be9bb9aa9adb2d421b728430
Author: Chengfeng Ye <cyeaa@xxxxxxxxxxxxxx>
Date: Fri Nov 5 06:36:36 2021 -0700
nfc: pn533: Fix double free when pn533_fill_fragment_skbs() fails
[ Upstream commit 9fec40f850658e00a14a7dd9e06f7fbc7e59cc4a ]
skb is already freed by dev_kfree_skb in pn533_fill_fragment_skbs,
but follow error handler branch when pn533_fill_fragment_skbs()
fails, skb is freed again, results in double free issue. Fix this
by not free skb in error path of pn533_fill_fragment_skbs.
Fixes: 963a82e07d4e ("NFC: pn533: Split large Tx frames in chunks")
Fixes: 93ad42020c2d ("NFC: pn533: Target mode Tx fragmentation support")
Signed-off-by: Chengfeng Ye <cyeaa@xxxxxxxxxxxxxx>
Reviewed-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/nfc/pn533.c b/drivers/nfc/pn533.c
index 001c12867e430..9e0d74a08d584 100644
--- a/drivers/nfc/pn533.c
+++ b/drivers/nfc/pn533.c
@@ -2592,7 +2592,7 @@ static int pn533_fill_fragment_skbs(struct pn533 *dev, struct sk_buff *skb)
frag = pn533_alloc_skb(dev, frag_size);
if (!frag) {
skb_queue_purge(&dev->fragment_skb);
- break;
+ return -ENOMEM;
}
if (!dev->tgt_mode) {
@@ -2662,7 +2662,7 @@ static int pn533_transceive(struct nfc_dev *nfc_dev,
/* jumbo frame ? */
if (skb->len > PN533_CMD_DATAEXCH_DATA_MAXLEN) {
rc = pn533_fill_fragment_skbs(dev, skb);
- if (rc <= 0)
+ if (rc < 0)
goto error;
skb = skb_dequeue(&dev->fragment_skb);
@@ -2734,7 +2734,7 @@ static int pn533_tm_send(struct nfc_dev *nfc_dev, struct sk_buff *skb)
/* let's split in multiple chunks if size's too big */
if (skb->len > PN533_CMD_DATAEXCH_DATA_MAXLEN) {
rc = pn533_fill_fragment_skbs(dev, skb);
- if (rc <= 0)
+ if (rc < 0)
goto error;
/* get the first skb */
