[PATCH net v2] nfc: nci: Fix uninit-value in nci_dev_up and nci_ntf_packet

[PATCH net v2] nfc: nci: Fix uninit-value in nci_dev_up and nci_ntf_packet

[Ryosuke Yasuoka]

syzbot reported the following uninit-value access issue [1][2]:

nci_rx_work() parses and processes received packet. When the payload
length is zero, each message type handler reads uninitialized payload
and KMSAN detects this issue. The receipt of a packet with a zero-size
payload is considered unexpected, and therefore, such packets should be
silently discarded.

This patch resolved this issue by checking payload size before calling
each message type handler codes.

Fixes: 6a2968aaf50c ("NFC: basic NCI protocol implementation")
Reported-and-tested-by: syzbot+7ea9413ea6749baf5574@syzkaller.appspotmail.com
Reported-and-tested-by: syzbot+29b5ca705d2e0f4a44d2@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=7ea9413ea6749baf5574 [1]
Closes: https://syzkaller.appspot.com/bug?extid=29b5ca705d2e0f4a44d2 [2]
Signed-off-by: Ryosuke Yasuoka <ryasuoka@redhat.com>
---

v2
- Fix typo in commit message
- Remove Call Trace from commit message that syzbot reported. Make it
  shorter than the previous version.
- Check the payload length in earlier code path. And it can address
  another reported syzbot bug too. [2]

v1
https://lore.kernel.org/all/20240312145658.417288-1-ryasuoka@redhat.com/


 net/nfc/nci/core.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
index 6c9592d05120..f471fc54c6a1 100644
--- a/net/nfc/nci/core.c
+++ b/net/nfc/nci/core.c
@@ -1512,6 +1512,11 @@ 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;
+		}
+
 		/* Process frame */
 		switch (nci_mt(skb->data)) {
 		case NCI_MT_RSP_PKT:
-- 
2.44.0

Re: [PATCH net v2] nfc: nci: Fix uninit-value in nci_dev_up and nci_ntf_packet

[Jiri Pirko]

Wed, Mar 20, 2024 at 01:54:10AM CET, ryasuoka@redhat.com wrote:
>syzbot reported the following uninit-value access issue [1][2]:
>
>nci_rx_work() parses and processes received packet. When the payload
>length is zero, each message type handler reads uninitialized payload
>and KMSAN detects this issue. The receipt of a packet with a zero-size
>payload is considered unexpected, and therefore, such packets should be
>silently discarded.
>
>This patch resolved this issue by checking payload size before calling
>each message type handler codes.

Nit. Instead of talking about "this patch" in this patch description,
you should use imperative mood to tell the codebase what to do.

https://www.kernel.org/doc/html/v6.6/process/submitting-patches.html#describe-your-changes


Patch looks ok.


>
>Fixes: 6a2968aaf50c ("NFC: basic NCI protocol implementation")
>Reported-and-tested-by: syzbot+7ea9413ea6749baf5574@syzkaller.appspotmail.com
>Reported-and-tested-by: syzbot+29b5ca705d2e0f4a44d2@syzkaller.appspotmail.com
>Closes: https://syzkaller.appspot.com/bug?extid=7ea9413ea6749baf5574 [1]
>Closes: https://syzkaller.appspot.com/bug?extid=29b5ca705d2e0f4a44d2 [2]
>Signed-off-by: Ryosuke Yasuoka <ryasuoka@redhat.com>
>---
>
>v2
>- Fix typo in commit message
>- Remove Call Trace from commit message that syzbot reported. Make it
>  shorter than the previous version.
>- Check the payload length in earlier code path. And it can address
>  another reported syzbot bug too. [2]
>
>v1
>https://lore.kernel.org/all/20240312145658.417288-1-ryasuoka@redhat.com/
>
>
> net/nfc/nci/core.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
>diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
>index 6c9592d05120..f471fc54c6a1 100644
>--- a/net/nfc/nci/core.c
>+++ b/net/nfc/nci/core.c
>@@ -1512,6 +1512,11 @@ 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;
>+		}
>+
> 		/* Process frame */
> 		switch (nci_mt(skb->data)) {
> 		case NCI_MT_RSP_PKT:
>-- 
>2.44.0
>
>

Re: [PATCH net v2] nfc: nci: Fix uninit-value in nci_dev_up and nci_ntf_packet

[Jeremy Cline]

On Tue, Mar 19, 2024, at 8:54 PM, Ryosuke Yasuoka wrote:
> syzbot reported the following uninit-value access issue [1][2]:
>
> nci_rx_work() parses and processes received packet. When the payload
> length is zero, each message type handler reads uninitialized payload
> and KMSAN detects this issue. The receipt of a packet with a zero-size
> payload is considered unexpected, and therefore, such packets should be
> silently discarded.
>
> This patch resolved this issue by checking payload size before calling
> each message type handler codes.
>
> Fixes: 6a2968aaf50c ("NFC: basic NCI protocol implementation")
> Reported-and-tested-by: syzbot+7ea9413ea6749baf5574@syzkaller.appspotmail.com
> Reported-and-tested-by: syzbot+29b5ca705d2e0f4a44d2@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=7ea9413ea6749baf5574 [1]
> Closes: https://syzkaller.appspot.com/bug?extid=29b5ca705d2e0f4a44d2 [2]
> Signed-off-by: Ryosuke Yasuoka <ryasuoka@redhat.com>
> ---

For what it's worth,

Reviewed-by: Jeremy Cline <jeremy@jcline.org>

Re: [PATCH net v2] nfc: nci: Fix uninit-value in nci_dev_up and nci_ntf_packet

[Krzysztof Kozlowski]

On 20/03/2024 01:54, Ryosuke Yasuoka wrote:
> syzbot reported the following uninit-value access issue [1][2]:
> 
> nci_rx_work() parses and processes received packet. When the payload
> length is zero, each message type handler reads uninitialized payload
> and KMSAN detects this issue. The receipt of a packet with a zero-size
> payload is considered unexpected, and therefore, such packets should be
> silently discarded.
> 
> This patch resolved this issue by checking payload size before calling
> each message type handler codes.
> 
> Fixes: 6a2968aaf50c ("NFC: basic NCI protocol implementation")
> Reported-and-tested-by: syzbot+7ea9413ea6749baf5574@syzkaller.appspotmail.com
> Reported-and-tested-by: syzbot+29b5ca705d2e0f4a44d2@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=7ea9413ea6749baf5574 [1]
> Closes: https://syzkaller.appspot.com/bug?extid=29b5ca705d2e0f4a44d2 [2]
> Signed-off-by: Ryosuke Yasuoka <ryasuoka@redhat.com>
> ---
> 
> v2
> - Fix typo in commit message
> - Remove Call Trace from commit message that syzbot reported. Make it
>   shorter than the previous version.
> - Check the payload length in earlier code path. And it can address
>   another reported syzbot bug too. [2]

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof

Re: [PATCH net v2] nfc: nci: Fix uninit-value in nci_dev_up and nci_ntf_packet

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (main)
by David S. Miller <davem@davemloft.net>:

On Wed, 20 Mar 2024 09:54:10 +0900 you wrote:
> syzbot reported the following uninit-value access issue [1][2]:
> 
> nci_rx_work() parses and processes received packet. When the payload
> length is zero, each message type handler reads uninitialized payload
> and KMSAN detects this issue. The receipt of a packet with a zero-size
> payload is considered unexpected, and therefore, such packets should be
> silently discarded.
> 
> [...]

Here is the summary with links:
  - [net,v2] nfc: nci: Fix uninit-value in nci_dev_up and nci_ntf_packet
    https://git.kernel.org/netdev/net/c/d24b03535e5e

You are awesome, thank you!
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