From 572599cbf17affee6aa85b57b661115faac51eeb Mon Sep 17 00:00:00 2001 From: Chengfeng Ye Date: Fri, 5 Nov 2021 06:36:36 -0700 Subject: [PATCH] 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 Reviewed-by: Dan Carpenter Reviewed-by: Krzysztof Kozlowski Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/nfc/pn533/pn533.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/nfc/pn533/pn533.c b/drivers/nfc/pn533/pn533.c index 3ea38ce86cc9..807b7b37d9dc 100644 --- a/drivers/nfc/pn533/pn533.c +++ b/drivers/nfc/pn533/pn533.c @@ -2072,7 +2072,7 @@ 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) { @@ -2143,7 +2143,7 @@ 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); @@ -2215,7 +2215,7 @@ 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 */