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 08FB6449B0F; Thu, 30 Jul 2026 16:11:09 +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=1785427870; cv=none; b=P4GKc8Z7kbUu63Sa3yLHsEhVLjCo0ruC6h+YVO8k11HOKw2bW6txEYDWnJrkV74np1lFffTLae0AJgqH4pY2VvGxeoZcxiG67b45516E7011eQsORud/e7KulWLz0XCgjvBjAYur0rCgFbYG+EhO8Sdsy6R6RlwV5vA+BHzIvJQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785427870; c=relaxed/simple; bh=LZ8ShmpaStcdeLWs8zzyD4Pcr1ODFm49gCkuXwwPMhs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NgVtQ3F37uVOcmBmk8jzuUPBod6HqDtzgxnv2mjPUT/6Z/ZDgVxwYYO9TDR/VxgW/T66/8oLJ13iDA1BEb2FXoMVNafT7Rn94grlqeXJ8Aq6RIj9Gd4/3q9azixKd8s44Hrvvx/yZCdK+33DSAwBodv9WbR7wVKJWv+q2e+Xh8E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=qppnqMKO; 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="qppnqMKO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5BF751F000E9; Thu, 30 Jul 2026 16:11:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1785427868; bh=pR0TMMnA9rTdAGYPXB25wC6xFCs9wJHC2zZcxnJtTqY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=qppnqMKOaqXy7leYW9NBJ5ES9LCLMNJu9xetPUMGiEqazhTPkhb8AdgSksr0iDbKz MRNjUN6QivwyozwhSB3jZy08yuKHH16yqNLtkHhsmuiI0DEkoQ2t4ZNOPFU6slCHDp Gp5nRYYPPHIaPBFMSYyRShJXwM/19NXti7n+cj0s= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Alexandra Winter , Hidayath Khan , Jakub Kicinski Subject: [PATCH 6.6 320/484] net/af_iucv: fix NULL deref in afiucv_hs_callback_syn() Date: Thu, 30 Jul 2026 16:13:37 +0200 Message-ID: <20260730141430.438391329@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260730141423.392222816@linuxfoundation.org> References: <20260730141423.392222816@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 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Hidayath Khan commit 47a5116e56a6b6fe1e909f244e39cd0fc26ceee4 upstream. afiucv_hs_callback_syn() allocates the child socket with GFP_ATOMIC. If the allocation fails, nsk is NULL. The connection-refused path is entered when the listen state check fails, the accept backlog is full, or nsk is NULL. The code unconditionally calls iucv_sock_kill(nsk) in that path. iucv_sock_kill() does not accept a NULL socket pointer and immediately dereferences sk via sock_flag(sk, SOCK_ZAPPED). When nsk is NULL, calling iucv_sock_kill(nsk) results in a NULL pointer dereference. Only call iucv_sock_kill() when a child socket was successfully allocated. Fixes: 3881ac441f64 ("af_iucv: add HiperSockets transport") Cc: stable@vger.kernel.org Reviewed-by: Alexandra Winter Signed-off-by: Hidayath Khan Link: https://patch.msgid.link/20260709191732.124092-1-hidayath@linux.ibm.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/iucv/af_iucv.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/net/iucv/af_iucv.c +++ b/net/iucv/af_iucv.c @@ -1873,7 +1873,8 @@ static int afiucv_hs_callback_syn(struct afiucv_swap_src_dest(skb); trans_hdr->flags = AF_IUCV_FLAG_SYN | AF_IUCV_FLAG_FIN; err = dev_queue_xmit(skb); - iucv_sock_kill(nsk); + if (nsk) + iucv_sock_kill(nsk); bh_unlock_sock(sk); goto out; }