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 5658F442385; Mon, 17 Aug 2026 14:31:51 +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=1786977112; cv=none; b=QsSyEX4h1cVGMXfVDBF4fp4tDwbps+BIPdENGUvB4BBgMyQoojkrFNLhUc5nRrV1dyQ8o/F0a/9R4RrQn9g/E/yD/IyXq98J0Hm5N2On2G62BN8Ek8z9sE9ZXVIYdpEFyK/ReSe3eCj+kA8EVe6g+R06J9IMGKkz65h9C9M62VI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786977112; c=relaxed/simple; bh=djr22XcSqsfSJiTHjs7PH+OGWIooedueTmmHjUQ4idM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=gWMJshXWzsUloayXM1MTeVbJ7ysJGmUbgpPSiL3StLU2ygO87pMyDAB3srhZ9cFqZqFjXfSWVUdPR6WDtI3N59ulrsMuMm5UlCCURCNrbNNW/jaD4krOtrOwXYqA8kGLGN1aMLDmOexeA616eaym6BbwPXGIDxlrfeAPNvBA5VE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=WdPKgydf; 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="WdPKgydf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AEDA71F000E9; Mon, 17 Aug 2026 14:31:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786977111; bh=nsVGxIDhdp62pUNCPANqVuN8S0rCHm+SX7aFsamt5Nc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=WdPKgydfTztyay9/fm/07B2ANtJxgwHlxdg8KSHSzElxE97qQTJaqEz8N9IdeH43g JeaOvErOtBq/Vi15LIh8hvam4p/Iu9WoOfDOeNYmchXV8s+yMzfDakCX+JnndbGWdQ UlDjmPgJeotGbt/KFbW9K1IqbqdfYqPgrJKNKcpI= 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 5.15 215/456] net/af_iucv: fix NULL deref in afiucv_hs_callback_syn() Date: Mon, 17 Aug 2026 15:30:05 +0200 Message-ID: <20260817132548.596778063@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260817132539.792407575@linuxfoundation.org> References: <20260817132539.792407575@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: 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 @@ -1867,7 +1867,8 @@ 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; }