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.
Signed-off-by: Chengfeng Ye <[email protected]>
---
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 787bcbd290f7..a491db46e3bd 100644
--- a/drivers/nfc/pn533/pn533.c
+++ b/drivers/nfc/pn533/pn533.c
@@ -2216,7 +2216,7 @@ 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) {
@@ -2285,7 +2285,7 @@ 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);
@@ -2353,7 +2353,7 @@ 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 */
--
2.17.1
On 05/11/2021 14:36, Chengfeng Ye wrote:
> 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.
>
> Signed-off-by: Chengfeng Ye <[email protected]>
> ---
> drivers/nfc/pn533/pn533.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
Looks good, thanks:
Reviewed-by: Krzysztof Kozlowski <[email protected]>
Please do not forget about fixes tag. Here it is trickier because
pn533_fill_fragment_skbs() usage was introduced in two commits:
Fixes: 963a82e07d4e ("NFC: pn533: Split large Tx frames in chunks")
Fixes: 93ad42020c2d ("NFC: pn533: Target mode Tx fragmentation support")
Cc: <[email protected]>
Best regards,
Krzysztof
Hello:
This patch was applied to netdev/net.git (master)
by David S. Miller <[email protected]>:
On Fri, 5 Nov 2021 06:36:36 -0700 you wrote:
> 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.
>
> Signed-off-by: Chengfeng Ye <[email protected]>
>
> [...]
Here is the summary with links:
- [v2] nfc: pn533: Fix double free when pn533_fill_fragment_skbs() fails
https://git.kernel.org/netdev/net/c/9fec40f85065
You are awesome, thank you!
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