Commit 2c5a51f9 authored Nov 05, 2021 by Chengfeng Ye Committed by Greg Kroah-Hartman Nov 26, 2021

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: 963a82e0 ("NFC: pn533: Split large Tx frames in chunks")
Fixes: 93ad4202 ("NFC: pn533: Target mode Tx fragmentation support")
Signed-off-by: Chengfeng Ye <cyeaa@connect.ust.hk>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent 0c727425

drivers/nfc/pn533/pn533.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -2084,7 +2084,7 @@ 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) {
		@@ -2154,7 +2154,7 @@ 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);
		@@ -2226,7 +2226,7 @@ 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 */