From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 203B334389F; Sat, 30 May 2026 17:39:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780162750; cv=none; b=uzuhuJIcnJ4S13jACWucI6pxiS1pNQWaS5Bhn7CL+/7kmzTrMcNgcg3I2nmZ89e2m+UsyAuMRLdixSGxJpdybpL33sc7ha9xTAF7f4ZfHHXNQ1q8s+7xhBHvTCUqE1sOIrO9pxdRpCXArUEjjwFqqRLoQUcTzAg8BsjCtGcd/CY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780162750; c=relaxed/simple; bh=fTyl2cW08tw17qfi/vgdzb3pR/4XWRdN4EXQV3XiSxs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=aRc9qfNEdUAsVccCgn5+i8uQVR87QvBeeMr5CnE3JUljghIgyA8d5RNoOkdvHh42h81BCtwEw7d1PZYrdbXXc2E6bnz+n3LJ2LL1LWlmtDsEEHWE6smQlIQO2432tT/Qh8xFb3riFVOrhgnRUqH7YhUXvdO6ngihpiV+M8/q1AQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=BV9oh/jl; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="BV9oh/jl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EECE31F00898; Sat, 30 May 2026 17:39:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780162747; bh=b+CYAnMpxMnTOFE7Uiav6y6y+bmtmowWVt/pjuBg5+8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=BV9oh/jlUwhpaFfFXu5ZUa0VurF5Ndk4zoO6L3UYaOV2PVHojFyPKs0znWY2rUgaK 4jI+bS5oQp19F7WnZ6S2PfgBEy45HaM51c2QT7g0OOXbanOFK2QCzAhZv95vIzxxyf kgTmGmxd7rT7vz6RlAkr0RnH5Tw1QayqdNv4RuBs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Junxi Qian , Eric Dumazet , Jakub Kicinski Subject: [PATCH 5.15 052/776] nfc: llcp: add missing return after LLCP_CLOSED checks Date: Sat, 30 May 2026 17:56:06 +0200 Message-ID: <20260530160241.655014299@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260530160240.228940103@linuxfoundation.org> References: <20260530160240.228940103@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Junxi Qian commit 2b5dd4632966c39da6ba74dbc8689b309065e82c upstream. In nfc_llcp_recv_hdlc() and nfc_llcp_recv_disc(), when the socket state is LLCP_CLOSED, the code correctly calls release_sock() and nfc_llcp_sock_put() but fails to return. Execution falls through to the remainder of the function, which calls release_sock() and nfc_llcp_sock_put() again. This results in a double release_sock() and a refcount underflow via double nfc_llcp_sock_put(), leading to a use-after-free. Add the missing return statements after the LLCP_CLOSED branches in both functions to prevent the fall-through. Fixes: d646960f7986 ("NFC: Initial LLCP support") Signed-off-by: Junxi Qian Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20260408081006.3723-1-qjx1298677004@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/nfc/llcp_core.c | 2 ++ 1 file changed, 2 insertions(+) --- a/net/nfc/llcp_core.c +++ b/net/nfc/llcp_core.c @@ -1098,6 +1098,7 @@ static void nfc_llcp_recv_hdlc(struct nf if (sk->sk_state == LLCP_CLOSED) { release_sock(sk); nfc_llcp_sock_put(llcp_sock); + return; } /* Pass the payload upstream */ @@ -1189,6 +1190,7 @@ static void nfc_llcp_recv_disc(struct nf if (sk->sk_state == LLCP_CLOSED) { release_sock(sk); nfc_llcp_sock_put(llcp_sock); + return; } if (sk->sk_state == LLCP_CONNECTED) {