5.15-stable review patch. If anyone has any objections, please let me know.
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From: Edward Adam Davis eadavis@qq.com
[ 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@syzkaller.appspotmail.com Signed-off-by: Edward Adam Davis eadavis@qq.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- 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 6317e8505aaad..09d4ab0e63b1a 100644 --- a/drivers/nfc/virtual_ncidev.c +++ b/drivers/nfc/virtual_ncidev.c @@ -121,6 +121,10 @@ 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(ndev, skb); return count;