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 4.14-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-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 7075e1310d8ce40e3f2be9165882416765a9d511 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/pn533.c b/drivers/nfc/pn533/pn533.c index e3026e20f1696..52a1a2cae6c74 100644 --- a/drivers/nfc/pn533/pn533.c +++ b/drivers/nfc/pn533/pn533.c @@ -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 */