[PATCH] nfc: llcp: put the socket reference on a refused connection

[PATCH] nfc: llcp: put the socket reference on a refused connection

[Wentao Liang]

nfc_llcp_recv_connect() finds the listening socket with
nfc_llcp_sock_get(), which takes a socket reference.  A socket that has
been bound but not yet put into listen state is also linked into
local->sockets with dsap set to LLCP_SAP_SDP, so the lookup can return
it.  In that case the state check fails and the function jumps to fail,
which only sends a DM; the reference taken by the lookup is never
dropped.

Put the reference before jumping to fail on that path.

Fixes: a69f32af86e3 ("NFC: Socket linked list")
Cc: stable@vger.kernel.org
Assisted-by: DeepSeek-V4.1-Flash and OpenAI Codex
Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
---
 net/nfc/llcp_core.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/net/nfc/llcp_core.c b/net/nfc/llcp_core.c
index 74bf817007cf..92fd7e29ec8a 100644
--- a/net/nfc/llcp_core.c
+++ b/net/nfc/llcp_core.c
@@ -949,10 +949,15 @@ static void nfc_llcp_recv_connect(struct nfc_llcp_local *local,
 
 	if (dsap != LLCP_SAP_SDP) {
 		sock = nfc_llcp_sock_get(local, dsap, LLCP_SAP_SDP);
-		if (sock == NULL || sock->sk.sk_state != LLCP_LISTEN) {
+		if (sock == NULL) {
 			reason = LLCP_DM_NOBOUND;
 			goto fail;
 		}
+		if (sock->sk.sk_state != LLCP_LISTEN) {
+			reason = LLCP_DM_NOBOUND;
+			sock_put(&sock->sk);
+			goto fail;
+		}
 	} else {
 		const u8 *sn;
 		size_t sn_len;
-- 
2.34.1

Re: [PATCH] nfc: llcp: put the socket reference on a refused connection

[netdev-bot+sinfo]

Hi!

This is an automated message. This series looks like a fix, but its
commit messages seem to be missing some information:

 - How the issue was discovered, e.g. hit in production, hit during
   development, syzbot report, manual code inspection, LLM or static
   analysis tool scan.

 - Whether the issue was actually triggered, or is only theoretical
   (e.g. found by code inspection). If it was triggered please include
   the symptoms, like the stack trace or error messages.

Please do not repost the series just to address the above. Instead,
reply to this email with the missing information, so that reviewers
can take it into account. If the series needs another revision for
other reasons, please include the information in the commit messages
then.

The evaluation is done by an LLM so it may be wrong, if you think
that is the case please reply and explain.

Re: [PATCH] nfc: llcp: put the socket reference on a refused connection

[Krzysztof Kozlowski]

On Wed, 04 Nov 2026 02:28:11 +0000, Wentao Liang wrote:
> nfc_llcp_recv_connect() finds the listening socket with
> nfc_llcp_sock_get(), which takes a socket reference.  A socket that has
> been bound but not yet put into listen state is also linked into
> local->sockets with dsap set to LLCP_SAP_SDP, so the lookup can return
> it.  In that case the state check fails and the function jumps to fail,
> which only sends a DM; the reference taken by the lookup is never
> dropped.
> 
> Put the reference before jumping to fail on that path.
> 
> Fixes: a69f32af86e3 ("NFC: Socket linked list")
> Cc: stable@vger.kernel.org
> Assisted-by: DeepSeek-V4.1-Flash and OpenAI Codex
> Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
> ---
>  net/nfc/llcp_core.c | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 

Multiple things here:
1. Your team ignored completely previous feedback. Multiple times.

2. You use multiple identities with this email address, thus I doubt that we
   speak with an actual person.

3. Your bot does not even bother running checkpatch, right?

4. Nothing of this was reproduced nor tested.

5. Finally, the same feedback:
You sent multiple independent patches, to multiple independent
subsystems. The amount of these patches clearly suggest this was
AI generated and most likely not tested.

More importantly, you sent all this work without properly organizing
relevant patches into patchsets. This makes reviewing difficult
and might cause multiple reviewers to address the same issue.
Replying to the entire set is impossible and requires handling each
patch independently, instead of applying or discarding the set.
Maintainers also won't see the bigger picture of your work. Quite
worrying.

This is on the verge of hostile patch: bomb us with so many
contributions, we won't be able to handle them in efficient manner,
like responding ONCE to ask you to slow down.  Considering all this
is untested and LLM generated, I have even more doubts whether this
should be considered for review.

Please read kernel documentation BEFORE posting more work. It will
explain you how to identify subsystems, how to organize your work per
subsystem (so a patchset grouping multiple patches with a short cover
letter), how to document the issue discovery method and what was
or was not tested.

Best regards,
Krzysztof