* [PATCH net v4] nfc: nci: Fix uninit-value in nci_rx_work
@ 2024-05-09 11:30 Ryosuke Yasuoka
2024-05-09 13:44 ` Simon Horman
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Ryosuke Yasuoka @ 2024-05-09 11:30 UTC (permalink / raw
To: krzk, davem, edumazet, kuba, pabeni, horms
Cc: Ryosuke Yasuoka, netdev, linux-kernel, syoshida,
syzbot+d7b4dc6cd50410152534
syzbot reported the following uninit-value access issue [1]
nci_rx_work() parses received packet from ndev->rx_q. It should be
validated header size, payload size and total packet size before
processing the packet. If an invalid packet is detected, it should be
silently discarded.
Fixes: d24b03535e5e ("nfc: nci: Fix uninit-value in nci_dev_up and nci_ntf_packet")
Reported-and-tested-by: syzbot+d7b4dc6cd50410152534@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=d7b4dc6cd50410152534 [1]
Signed-off-by: Ryosuke Yasuoka <ryasuoka@redhat.com>
---
v4
- v3 patch uses goto statement and it makes codes complicated. So this
patch simply calls kfree_skb inside loop and remove goto statement.
- [2] inserted kcov_remote_stop() to fix kcov check. However, as we
discuss about my v3 patch [3], it should not exit the for statement
and should continue processing subsequent packets. This patch removes
them and simply insert continue statement.
[2] https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=19e35f24750d
v3
https://lore.kernel.org/netdev/20240502082323.250739-1-ryasuoka@redhat.com/T/
- As Simon pointed out, the valid packets will reach invalid_pkt_free
and kfree_skb(skb) after being handled correctly in switch statement.
It can lead to double free issues, which is not intended. So this patch
uses "continue" instead of "break" in switch statement.
- In the current implementation, once zero payload size is detected, the
for statement exits. It should continue processing subsequent packets.
So this patch just frees skb in invalid_pkt_free when the invalid
packets are detected. [3]
v2
https://lore.kernel.org/lkml/20240428134525.GW516117@kernel.org/T/
- The v1 patch only checked whether skb->len is zero. This patch also
checks header size, payload size and total packet size.
v1
https://lore.kernel.org/linux-kernel/CANn89iJrQevxPFLCj2P=U+XSisYD0jqrUQpa=zWMXTjj5+RriA@mail.gmail.com/T/
net/nfc/nci/core.c | 30 ++++++++++++++++++++++++------
1 file changed, 24 insertions(+), 6 deletions(-)
diff --git a/net/nfc/nci/core.c b/net/nfc/nci/core.c
index b133dc55304c..0aaff30cb68f 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)
@@ -1516,24 +1526,32 @@ 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)) {
+ if (!skb->len) {
kfree_skb(skb);
- kcov_remote_stop();
- break;
+ continue;
}
/* Process frame */
switch (nci_mt(skb->data)) {
case NCI_MT_RSP_PKT:
- nci_rsp_packet(ndev, skb);
+ if (nci_valid_size(skb, NCI_CTRL_HDR_SIZE))
+ nci_rsp_packet(ndev, skb);
+ else
+ kfree_skb(skb);
break;
case NCI_MT_NTF_PKT:
- nci_ntf_packet(ndev, skb);
+ if (nci_valid_size(skb, NCI_CTRL_HDR_SIZE))
+ nci_ntf_packet(ndev, skb);
+ else
+ kfree_skb(skb);
break;
case NCI_MT_DATA_PKT:
- nci_rx_data_packet(ndev, skb);
+ if (nci_valid_size(skb, NCI_DATA_HDR_SIZE))
+ nci_rx_data_packet(ndev, skb);
+ else
+ kfree_skb(skb);
break;
default:
--
2.44.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH net v4] nfc: nci: Fix uninit-value in nci_rx_work
2024-05-09 11:30 [PATCH net v4] nfc: nci: Fix uninit-value in nci_rx_work Ryosuke Yasuoka
@ 2024-05-09 13:44 ` Simon Horman
2024-05-09 14:39 ` Krzysztof Kozlowski
2024-05-11 2:06 ` Jakub Kicinski
2 siblings, 0 replies; 6+ messages in thread
From: Simon Horman @ 2024-05-09 13:44 UTC (permalink / raw
To: Ryosuke Yasuoka
Cc: krzk, davem, edumazet, kuba, pabeni, netdev, linux-kernel,
syoshida, syzbot+d7b4dc6cd50410152534
On Thu, May 09, 2024 at 08:30:33PM +0900, Ryosuke Yasuoka wrote:
> syzbot reported the following uninit-value access issue [1]
>
> nci_rx_work() parses received packet from ndev->rx_q. It should be
> validated header size, payload size and total packet size before
> processing the packet. If an invalid packet is detected, it should be
> silently discarded.
>
> Fixes: d24b03535e5e ("nfc: nci: Fix uninit-value in nci_dev_up and nci_ntf_packet")
> Reported-and-tested-by: syzbot+d7b4dc6cd50410152534@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=d7b4dc6cd50410152534 [1]
> Signed-off-by: Ryosuke Yasuoka <ryasuoka@redhat.com>
I suggest giving time for Krzysztof to review this.
But from my side this looks good.
Reviewed-by: Simon Horman <horms@kernel.org>
...
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH net v4] nfc: nci: Fix uninit-value in nci_rx_work
2024-05-09 11:30 [PATCH net v4] nfc: nci: Fix uninit-value in nci_rx_work Ryosuke Yasuoka
2024-05-09 13:44 ` Simon Horman
@ 2024-05-09 14:39 ` Krzysztof Kozlowski
2024-05-11 2:06 ` Jakub Kicinski
2 siblings, 0 replies; 6+ messages in thread
From: Krzysztof Kozlowski @ 2024-05-09 14:39 UTC (permalink / raw
To: Ryosuke Yasuoka, davem, edumazet, kuba, pabeni, horms
Cc: netdev, linux-kernel, syoshida, syzbot+d7b4dc6cd50410152534
On 09/05/2024 13:30, Ryosuke Yasuoka wrote:
> syzbot reported the following uninit-value access issue [1]
>
> nci_rx_work() parses received packet from ndev->rx_q. It should be
> validated header size, payload size and total packet size before
> processing the packet. If an invalid packet is detected, it should be
> silently discarded.
>
> Fixes: d24b03535e5e ("nfc: nci: Fix uninit-value in nci_dev_up and nci_ntf_packet")
> Reported-and-tested-by: syzbot+d7b4dc6cd50410152534@syzkaller.appspotmail.com
> Closes: https://syzkaller.appspot.com/bug?extid=d7b4dc6cd50410152534 [1]
> Signed-off-by: Ryosuke Yasuoka <ryasuoka@redhat.com>
> ---
> v4
> - v3 patch uses goto statement and it makes codes complicated. So this
> patch simply calls kfree_skb inside loop and remove goto statement.
> - [2] inserted kcov_remote_stop() to fix kcov check. However, as we
> discuss about my v3 patch [3], it should not exit the for statement
> and should continue processing subsequent packets. This patch removes
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Best regards,
Krzysztof
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH net v4] nfc: nci: Fix uninit-value in nci_rx_work
2024-05-09 11:30 [PATCH net v4] nfc: nci: Fix uninit-value in nci_rx_work Ryosuke Yasuoka
2024-05-09 13:44 ` Simon Horman
2024-05-09 14:39 ` Krzysztof Kozlowski
@ 2024-05-11 2:06 ` Jakub Kicinski
2024-05-11 11:02 ` Ryosuke Yasuoka
2 siblings, 1 reply; 6+ messages in thread
From: Jakub Kicinski @ 2024-05-11 2:06 UTC (permalink / raw
To: Ryosuke Yasuoka
Cc: krzk, davem, edumazet, pabeni, horms, netdev, linux-kernel,
syoshida, syzbot+d7b4dc6cd50410152534
On Thu, 9 May 2024 20:30:33 +0900 Ryosuke Yasuoka wrote:
> - if (!nci_plen(skb->data)) {
> + if (!skb->len) {
> kfree_skb(skb);
> - kcov_remote_stop();
> - break;
> + continue;
the change from break to continue looks unrelated
> }
> - nci_ntf_packet(ndev, skb);
> + if (nci_valid_size(skb, NCI_CTRL_HDR_SIZE))
> + if (nci_valid_size(skb, NCI_DATA_HDR_SIZE))
#define NCI_CTRL_HDR_SIZE 3
#define NCI_DATA_HDR_SIZE 3
you can add a BUILD_BUG_ON(NCI_CTRL_HDR_SIZE == NCI_DATA_HDR_SIZE)
and save all the code duplication.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH net v4] nfc: nci: Fix uninit-value in nci_rx_work
2024-05-11 2:06 ` Jakub Kicinski
@ 2024-05-11 11:02 ` Ryosuke Yasuoka
2024-05-13 14:25 ` Jakub Kicinski
0 siblings, 1 reply; 6+ messages in thread
From: Ryosuke Yasuoka @ 2024-05-11 11:02 UTC (permalink / raw
To: Jakub Kicinski
Cc: krzk, davem, edumazet, pabeni, horms, netdev, linux-kernel,
syoshida, syzbot+d7b4dc6cd50410152534
Thank you for your review.
On Fri, May 10, 2024 at 07:06:13PM -0700, Jakub Kicinski wrote:
> On Thu, 9 May 2024 20:30:33 +0900 Ryosuke Yasuoka wrote:
> > - if (!nci_plen(skb->data)) {
> > + if (!skb->len) {
> > kfree_skb(skb);
> > - kcov_remote_stop();
> > - break;
> > + continue;
>
> the change from break to continue looks unrelated
OK. I'll leave this break in this patch. I'll send another patch about
it.
> > }
>
> > - nci_ntf_packet(ndev, skb);
> > + if (nci_valid_size(skb, NCI_CTRL_HDR_SIZE))
>
> > + if (nci_valid_size(skb, NCI_DATA_HDR_SIZE))
>
>
> #define NCI_CTRL_HDR_SIZE 3
> #define NCI_DATA_HDR_SIZE 3
>
> you can add a BUILD_BUG_ON(NCI_CTRL_HDR_SIZE == NCI_DATA_HDR_SIZE)
> and save all the code duplication.
>
Sorry I don't get it. Do you mean I just insert
BUILD_BUG_ON(NCI_CTRL_HDR_SIZE != NCI_DATA_HDR_SIZE) or insert this and
clean up the code duplication like this? (It is just a draft. I just
share what I mean.) I can avoid to call nci_valid_size() repeatedly
inside the switch statement.
static void nci_rx_work(struct work_struct *work)
{
...
if (!skb->len) {
kfree_skb(skb);
kcov_remote_stop();
break;
}
BUILD_BUG_ON(NCI_CTRL_HDR_SIZE != NCI_DATA_HDR_SIZE);
unsigned int hdr_size = NCI_CTRL_HDR_SIZE;
if (!nci_valid_size(skb, hdr_size)) {
kfree_skb(skb);
continue;
}
/* Process frame */
switch (nci_mt(skb->data)) {
case NCI_MT_RSP_PKT:
nci_rsp_packet(ndev, skb);
break;
case NCI_MT_NTF_PKT:
nci_ntf_packet(ndev, skb);
break;
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH net v4] nfc: nci: Fix uninit-value in nci_rx_work
2024-05-11 11:02 ` Ryosuke Yasuoka
@ 2024-05-13 14:25 ` Jakub Kicinski
0 siblings, 0 replies; 6+ messages in thread
From: Jakub Kicinski @ 2024-05-13 14:25 UTC (permalink / raw
To: Ryosuke Yasuoka
Cc: krzk, davem, edumazet, pabeni, horms, netdev, linux-kernel,
syoshida, syzbot+d7b4dc6cd50410152534
On Sat, 11 May 2024 20:02:28 +0900 Ryosuke Yasuoka wrote:
> Sorry I don't get it. Do you mean I just insert
> BUILD_BUG_ON(NCI_CTRL_HDR_SIZE != NCI_DATA_HDR_SIZE) or insert this and
> clean up the code duplication like this? (It is just a draft. I just
> share what I mean.) I can avoid to call nci_valid_size() repeatedly
> inside the switch statement.
>
> static void nci_rx_work(struct work_struct *work)
> {
> ...
> if (!skb->len) {
> kfree_skb(skb);
> kcov_remote_stop();
> break;
> }
>
> BUILD_BUG_ON(NCI_CTRL_HDR_SIZE != NCI_DATA_HDR_SIZE);
> unsigned int hdr_size = NCI_CTRL_HDR_SIZE;
>
> if (!nci_valid_size(skb, hdr_size)) {
> kfree_skb(skb);
> continue;
> }
>
> /* Process frame */
> switch (nci_mt(skb->data)) {
> case NCI_MT_RSP_PKT:
> nci_rsp_packet(ndev, skb);
> break;
>
> case NCI_MT_NTF_PKT:
> nci_ntf_packet(ndev, skb);
> break;
Yes, that's what I meant. I'd probably merge the nci_valid_size()
check with the !skb->len check, too.
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2024-05-13 14:25 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2024-05-09 11:30 [PATCH net v4] nfc: nci: Fix uninit-value in nci_rx_work Ryosuke Yasuoka
2024-05-09 13:44 ` Simon Horman
2024-05-09 14:39 ` Krzysztof Kozlowski
2024-05-11 2:06 ` Jakub Kicinski
2024-05-11 11:02 ` Ryosuke Yasuoka
2024-05-13 14:25 ` Jakub Kicinski
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