lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Message-ID: <ZOMrD1DHeys0nFwt@gmail.com> Date: Mon, 21 Aug 2023 02:14:55 -0700 From: Breno Leitao <leitao@...ian.org> To: Gabriel Krisman Bertazi <krisman@...e.de> Cc: sdf@...gle.com, axboe@...nel.dk, asml.silence@...il.com, willemdebruijn.kernel@...il.com, martin.lau@...ux.dev, bpf@...r.kernel.org, linux-kernel@...r.kernel.org, netdev@...r.kernel.org, io-uring@...r.kernel.org, kuba@...nel.org, pabeni@...hat.com Subject: Re: [PATCH v3 8/9] io_uring/cmd: BPF hook for getsockopt cmd On Thu, Aug 17, 2023 at 03:08:47PM -0400, Gabriel Krisman Bertazi wrote: > Breno Leitao <leitao@...ian.org> writes: > > > Add BPF hook support for getsockopts io_uring command. So, BPF cgroups > > programs can run when SOCKET_URING_OP_GETSOCKOPT command is executed > > through io_uring. > > > > This implementation follows a similar approach to what > > __sys_getsockopt() does, but, using USER_SOCKPTR() for optval instead of > > kernel pointer. > > > > Signed-off-by: Breno Leitao <leitao@...ian.org> > > --- > > io_uring/uring_cmd.c | 18 +++++++++++++----- > > 1 file changed, 13 insertions(+), 5 deletions(-) > > > > diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c > > index a567dd32df00..9e08a14760c3 100644 > > --- a/io_uring/uring_cmd.c > > +++ b/io_uring/uring_cmd.c > > @@ -5,6 +5,8 @@ > > #include <linux/io_uring.h> > > #include <linux/security.h> > > #include <linux/nospec.h> > > +#include <linux/compat.h> > > +#include <linux/bpf-cgroup.h> > > > > #include <uapi/linux/io_uring.h> > > #include <uapi/asm-generic/ioctls.h> > > @@ -184,17 +186,23 @@ static inline int io_uring_cmd_getsockopt(struct socket *sock, > > if (err) > > return err; > > > > - if (level == SOL_SOCKET) { > > + err = -EOPNOTSUPP; > > + if (level == SOL_SOCKET) > > err = sk_getsockopt(sock->sk, level, optname, > > USER_SOCKPTR(optval), > > KERNEL_SOCKPTR(&optlen)); > > - if (err) > > - return err; > > > > + if (!(issue_flags & IO_URING_F_COMPAT)) > > + err = BPF_CGROUP_RUN_PROG_GETSOCKOPT(sock->sk, level, > > + optname, > > + USER_SOCKPTR(optval), > > + KERNEL_SOCKPTR(&optlen), > > + optlen, err); > > + > > + if (!err) > > return optlen; > > - } > > Shouldn't you call sock->ops->getsockopt for level!=SOL_SOCKET prior to > running the hook? > Before this patch, it would bail out with EOPNOTSUPP, > but now the bpf hook gets called even for level!=SOL_SOCKET, which > doesn't fit __sys_getsockopt. Am I misreading the code? Not really, sock->ops->getsockopt() does not suport sockptr_t, but __user addresses, differently from setsockopt() int (*setsockopt)(struct socket *sock, int level, int optname, sockptr_t optval, unsigned int optlen); int (*getsockopt)(struct socket *sock, int level, int optname, char __user *optval, int __user *optlen); In order to be able to call sock->ops->getsockopt(), the callback function will need to accepted sockptr.
Powered by blists - more mailing lists