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 0216330567C; Thu, 30 Jul 2026 15:20:49 +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=1785424850; cv=none; b=UVJxpnVki8pP7KjTyp/ntvN/t2Z9UXf9Jixtrrx28YMinnSZo0SpVSzEdQyMBV0yTw+G4q+CYZZtjpdHhfGQGu6N/zZwZpAIkJcOC2R8QDl8cZyeuehEyuRAEFE+lmAJDFw6/Xmp4opwqSKQlhEtKG+3WqNhAIiEEmDvxQL2wCw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785424850; c=relaxed/simple; bh=qob1mpT56adDSNCN3bzgEqbMxgF1Uevyvfc2p9ir1sM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=VBjVev7YtouBFzDCm4TZon9x3+BfZDo6SW/q3mdHZWRdkDZ0p5Zh1fhH3Ktz4PMryNV7gVW6DqeeborxBC463sEe0yhuEpIl+s4MMhpW37tBztoKzjaN7ZYXEcy0eqI/YjWYewdad66KyEfgu87GifVXATOKUELEEpdbse7b9TQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=dh1mjlZb; 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="dh1mjlZb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5D7201F000E9; Thu, 30 Jul 2026 15:20:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1785424848; bh=cWKmAKUEufeX5R/aMXNXLkIPHNr8xLWp2ii8PZNh+zQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=dh1mjlZbO1uHftaUHhTQyABPVzzCc+A5oTQ1O0u4eO9JGB5EySW0ewRjna3o1lrgB yF1eY15csp2HUKlumDB/x31GSzSVWT08mMjDqAVbEy03oLnl1hfC5dqhdko6Ed3CRX hvnm7glVP+6Vr7vU/SF8kgm8KWjCJtRnr8cfqTb8= 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 6.18 537/675] net/af_iucv: fix NULL deref in afiucv_hs_callback_syn() Date: Thu, 30 Jul 2026 16:14:27 +0200 Message-ID: <20260730141456.556448849@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260730141445.110192266@linuxfoundation.org> References: <20260730141445.110192266@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 6.18-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 @@ -1872,7 +1872,8 @@ 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; }