6.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Edward Adam Davis <eadavis@xxxxxx>
[ Upstream commit 068648aab72c9ba7b0597354ef4d81ffaac7b979 ]
write$nci(r0, &(0x7f0000000740)=ANY=[@ANYBLOB="610501"], 0xf)
Syzbot constructed a write() call with a data length of 3 bytes but a count value
of 15, which passed too little data to meet the basic requirements of the function
nci_rf_intf_activated_ntf_packet().
Therefore, increasing the comparison between data length and count value to avoid
problems caused by inconsistent data length and count.
Reported-and-tested-by: syzbot+71bfed2b2bcea46c98f2@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Edward Adam Davis <eadavis@xxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/nfc/virtual_ncidev.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/drivers/nfc/virtual_ncidev.c b/drivers/nfc/virtual_ncidev.c
index 590b038e449e5..6b89d596ba9af 100644
--- a/drivers/nfc/virtual_ncidev.c
+++ b/drivers/nfc/virtual_ncidev.c
@@ -125,6 +125,10 @@ static ssize_t virtual_ncidev_write(struct file *file,
kfree_skb(skb);
return -EFAULT;
}
+ if (strnlen(skb->data, count) != count) {
+ kfree_skb(skb);
+ return -EINVAL;
+ }
nci_recv_frame(vdev->ndev, skb);
return count;
--
2.43.0
