From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Date: Thu, 23 Jul 2020 09:22:38 +0000 Subject: Re: [PATCH net-next] sctp: fix slab-out-of-bounds in SCTP_DELAYED_SACK processing Message-Id: <20200723092238.GA21143@lst.de> List-Id: References: <5955bc857c93d4bb64731ef7a9e90cb0094a8989.1595450200.git.marcelo.leitner@gmail.com> <20200722204231.GA3398@localhost.localdomain> In-Reply-To: <20200722204231.GA3398@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Marcelo Ricardo Leitner Cc: netdev@vger.kernel.org, Neil Horman , Christoph Hellwig , linux-sctp@vger.kernel.org On Wed, Jul 22, 2020 at 05:42:31PM -0300, Marcelo Ricardo Leitner wrote: > Cc'ing linux-sctp@vger.kernel.org. What do you think of this version, which I think is a little cleaner? diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 9a767f35971865..6ce460428af9f3 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -2749,31 +2749,12 @@ static void sctp_apply_asoc_delayed_ack(struct sctp_sack_info *params, * timer to expire. The default value for this is 2, setting this * value to 1 will disable the delayed sack algorithm. */ - -static int sctp_setsockopt_delayed_ack(struct sock *sk, - struct sctp_sack_info *params, - unsigned int optlen) +static int __sctp_setsockopt_delayed_ack(struct sock *sk, + struct sctp_sack_info *params) { struct sctp_sock *sp = sctp_sk(sk); struct sctp_association *asoc; - if (optlen = sizeof(struct sctp_sack_info)) { - if (params->sack_delay = 0 && params->sack_freq = 0) - return 0; - } else if (optlen = sizeof(struct sctp_assoc_value)) { - pr_warn_ratelimited(DEPRECATED - "%s (pid %d) " - "Use of struct sctp_assoc_value in delayed_ack socket option.\n" - "Use struct sctp_sack_info instead\n", - current->comm, task_pid_nr(current)); - - if (params->sack_delay = 0) - params->sack_freq = 1; - else - params->sack_freq = 0; - } else - return -EINVAL; - /* Validate value parameter. */ if (params->sack_delay > 500) return -EINVAL; @@ -2821,6 +2802,31 @@ static int sctp_setsockopt_delayed_ack(struct sock *sk, return 0; } +static int sctp_setsockopt_delayed_ack(struct sock *sk, + struct sctp_sack_info *params, + unsigned int optlen) +{ + if (optlen = sizeof(struct sctp_assoc_value)) { + struct sctp_sack_info p; + + pr_warn_ratelimited(DEPRECATED + "%s (pid %d) " + "Use of struct sctp_assoc_value in delayed_ack socket option.\n" + "Use struct sctp_sack_info instead\n", + current->comm, task_pid_nr(current)); + + memcpy(&p, params, sizeof(struct sctp_assoc_value)); + p.sack_freq = p.sack_delay ? 0 : 1; + return __sctp_setsockopt_delayed_ack(sk, &p); + } + + if (optlen != sizeof(struct sctp_sack_info)) + return -EINVAL; + if (params->sack_delay = 0 && params->sack_freq = 0) + return 0; + return __sctp_setsockopt_delayed_ack(sk, params); +} + /* 7.1.3 Initialization Parameters (SCTP_INITMSG) * * Applications can specify protocol parameters for the default association