On Wed, May 2, 2018 at 8:48 PM, Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx> wrote: > On Wed, May 02, 2018 at 08:27:05PM -0500, Wenwen Wang wrote: >> On Wed, May 2, 2018 at 8:24 PM, Marcelo Ricardo Leitner >> <marcelo.leitner@xxxxxxxxx> wrote: >> > 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 <wang6495@xxxxxxx> >> >> --- >> >> net/sctp/socket.c | 22 +++++++++++----------- >> >> 1 file changed, 11 insertions(+), 11 deletions(-) >> > >> > ? >> > This patch is the same as previous one. git send-email <old file> >> > maybe? >> > >> > Marcelo >> >> Thanks for your suggestion, Marcelo. I can send the old file. But, I >> have added a line of comment in this patch. > > I meant if you had sent the old patch again by accident, because you > said you worked on an old version of the tree, but then posted a patch > that also doesn't use the new MTU function I mentioned. > > Marcelo I worked on the latest kernel. But, I didn't find the MTU function sctp_mtu_payload(). The problematic function that I found is sctp_setsockopt_maxseg() located in the file net/sctp/socket.c. Thanks, Wenwen -- To unsubscribe from this list: send the line "unsubscribe linux-sctp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
