From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marcelo Ricardo Leitner Subject: Re: [PATCH] sctp: fix a potential missing-check bug Date: Wed, 2 May 2018 22:24:02 -0300 Message-ID: <20180503012402.GK5105@localhost.localdomain> References: <1525310145-28102-1-git-send-email-wang6495@umn.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Kangjie Lu , Vlad Yasevich , Neil Horman , "David S. Miller" , "open list:SCTP PROTOCOL" , "open list:NETWORKING [GENERAL]" , open list To: Wenwen Wang Return-path: Content-Disposition: inline In-Reply-To: <1525310145-28102-1-git-send-email-wang6495@umn.edu> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Wed, May 02, 2018 at 08:15:45PM -0500, Wenwen Wang wrote: > In sctp_setsockopt_maxseg(), the integer 'val' is compared against min_len > and max_len to check whether it is in the appropriate range. If it is not, > an error code -EINVAL will be returned. This is enforced by a security > check. But, this check is only executed when 'val' is not 0. In fact, if > 'val' is 0, it will be assigned with a new value (if the return value of > the function sctp_id2assoc() is not 0) in the following execution. However, > this new value of 'val' is not checked before it is used to assigned to > asoc->user_frag. That means it is possible that the new value of 'val' > could be out of the expected range. This can cause security issues > such as buffer overflows, e.g., the new value of 'val' is used as an index > to access a buffer. > > This patch inserts a check for the new value of 'val' to see if it is in > the expected range. If it is not, an error code -EINVAL will be returned. > > Signed-off-by: Wenwen Wang > --- > net/sctp/socket.c | 22 +++++++++++----------- > 1 file changed, 11 insertions(+), 11 deletions(-) ? This patch is the same as previous one. git send-email maybe? Marcelo