if either or both of MSG_ZEROCOPY and SOCK_ZEROCOPY have not been specified, the rm->data.op_mmp_znotifier allocation will be skipped. In this case, it is invalid ot pass down a cmsghdr with RDS_CMSG_ZCOPY_COOKIE, so return EINVAL from rds_msg_zcopy for this case.
Reported-by: syzbot+f893ae7bb2f6456df...@syzkaller.appspotmail.com Fixes: 0cebaccef3ac ("rds: zerocopy Tx support.") Signed-off-by: Sowmini Varadhan <sowmini.varad...@oracle.com> --- net/rds/send.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/net/rds/send.c b/net/rds/send.c index 028ab59..c848cbb 100644 --- a/net/rds/send.c +++ b/net/rds/send.c @@ -939,7 +939,8 @@ static int rds_cmsg_zcopy(struct rds_sock *rs, struct rds_message *rm, { u32 *cookie; - if (cmsg->cmsg_len < CMSG_LEN(sizeof(*cookie))) + if (cmsg->cmsg_len < CMSG_LEN(sizeof(*cookie)) || + !rm->data.op_mmp_znotifier) return -EINVAL; cookie = CMSG_DATA(cmsg); rm->data.op_mmp_znotifier->z_cookie = *cookie; -- 1.7.1