Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 5.14 760/849] nfc: pn533: Fix double free when pn533_fill_fragment_skbs() fails | Date | Mon, 15 Nov 2021 18:04:03 +0100 |
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From: Chengfeng Ye <cyeaa@connect.ust.hk>
[ 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@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> --- 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 cd64bfe204025..e8468e349e6fd 100644 --- a/drivers/nfc/pn533/pn533.c +++ b/drivers/nfc/pn533/pn533.c @@ -2218,7 +2218,7 @@ 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) { @@ -2287,7 +2287,7 @@ 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); @@ -2355,7 +2355,7 @@ 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 */ -- 2.33.0
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