This is a note to let you know that I've just added the patch titled nfc/nci: Add the inconsistency check between the input data length and count to the 6.9-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-nci-add-the-inconsistency-check-between-the-inpu.patch and it can be found in the queue-6.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 4beae712b85b17546abfec97ab16e8bf6388c2c8 Author: Edward Adam Davis <eadavis@xxxxxx> Date: Tue May 28 11:12:31 2024 +0800 nfc/nci: Add the inconsistency check between the input data length and count [ 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> 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;