Messages in this thread Patch in this message | | | From | Christophe JAILLET <> | Subject | [PATCH] nfc: st-nci: Fix an incorrect skb_buff size in 'st_nci_i2c_read()' | Date | Tue, 6 Aug 2019 16:16:40 +0200 |
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In 'st_nci_i2c_read()', we allocate a sk_buff with a size of ST_NCI_I2C_MIN_SIZE + len.
However, later on, we first 'skb_reserve()' ST_NCI_I2C_MIN_SIZE bytes, then we 'skb_put()' ST_NCI_I2C_MIN_SIZE bytes. Finally, if 'len' is not 0, we 'skb_put()' 'len' bytes.
So we use ST_NCI_I2C_MIN_SIZE*2 + len bytes.
This is incorrect and should already panic. I guess that it does not occur because of extra memory allocated because of some rounding.
Fix it and allocate enough room for the 'skb_reserve()' and the 'skb_put()' calls.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> --- This patch is LIKELY INCORRECT. So think twice to what is the correct solution before applying it. Maybe the skb_reserve should be axed or some other sizes are incorrect. There seems to be an issue, that's all I can say. --- drivers/nfc/st-nci/i2c.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/nfc/st-nci/i2c.c b/drivers/nfc/st-nci/i2c.c index 55d600cd3861..12e0425131c8 100644 --- a/drivers/nfc/st-nci/i2c.c +++ b/drivers/nfc/st-nci/i2c.c @@ -126,7 +126,7 @@ static int st_nci_i2c_read(struct st_nci_i2c_phy *phy, return -EBADMSG; } - *skb = alloc_skb(ST_NCI_I2C_MIN_SIZE + len, GFP_KERNEL); + *skb = alloc_skb(ST_NCI_I2C_MIN_SIZE * 2 + len, GFP_KERNEL); if (*skb == NULL) return -ENOMEM; -- 2.20.1
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