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Message-ID: <000000000000bbb92f061771d92a@google.com>
Date: Wed, 01 May 2024 22:26:51 -0700
From: syzbot <syzbot+d7b4dc6cd50410152534@...kaller.appspotmail.com>
To: linux-kernel@...r.kernel.org
Subject: Re: [syzbot] [PATCH net v3] nfc: nci: Fix uninit-value in nci_rx_work
For archival purposes, forwarding an incoming command email to
linux-kernel@...r.kernel.org.
***
Subject: [PATCH net v3] nfc: nci: Fix uninit-value in nci_rx_work
Author: ryasuoka@...hat.com
#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git e88c4cfcb7b888ac374916806f86c17d8ecaeb67
diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
index 0d26c8ec9993..e4f92a090022 100644
--- a/net/nfc/nci/core.c
+++ b/net/nfc/nci/core.c
@@ -1463,6 +1463,16 @@ int nci_core_ntf_packet(struct nci_dev *ndev, __u16 opcode,
ndev->ops->n_core_ops);
}
+static bool nci_valid_size(struct sk_buff *skb, unsigned int header_size)
+{
+ if (skb->len < header_size ||
+ !nci_plen(skb->data) ||
+ skb->len < header_size + nci_plen(skb->data)) {
+ return false;
+ }
+ return true;
+}
+
/* ---- NCI TX Data worker thread ---- */
static void nci_tx_work(struct work_struct *work)
@@ -1516,30 +1526,35 @@ static void nci_rx_work(struct work_struct *work)
nfc_send_to_raw_sock(ndev->nfc_dev, skb,
RAW_PAYLOAD_NCI, NFC_DIRECTION_RX);
- if (!nci_plen(skb->data)) {
- kfree_skb(skb);
- break;
- }
+ if (!skb->len)
+ goto invalid_pkt_free;
/* Process frame */
switch (nci_mt(skb->data)) {
case NCI_MT_RSP_PKT:
+ if (!nci_valid_size(skb, NCI_CTRL_HDR_SIZE))
+ goto invalid_pkt_free;
nci_rsp_packet(ndev, skb);
- break;
+ continue;
case NCI_MT_NTF_PKT:
+ if (!nci_valid_size(skb, NCI_CTRL_HDR_SIZE))
+ goto invalid_pkt_free;
nci_ntf_packet(ndev, skb);
- break;
+ continue;
case NCI_MT_DATA_PKT:
+ if (!nci_valid_size(skb, NCI_DATA_HDR_SIZE))
+ goto invalid_pkt_free;
nci_rx_data_packet(ndev, skb);
- break;
+ continue;
default:
pr_err("unknown MT 0x%x\n", nci_mt(skb->data));
- kfree_skb(skb);
- break;
+ goto invalid_pkt_free;
}
+invalid_pkt_free:
+ kfree_skb(skb);
}
/* check if a data exchange timeout has occurred */
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