On Tue, Nov 22, 2022 at 07:18:24AM -0800, Casey Schaufler wrote:
> On 11/22/2022 2:31 AM, Joel Granados wrote:
> > Signed-off-by: Joel Granados <j.granados@xxxxxxxxxxx>
> > ---
> > drivers/nvme/host/core.c | 10 ++++++++++
> > include/linux/fs.h | 2 ++
> > include/linux/lsm_hook_defs.h | 3 ++-
> > include/linux/security.h | 16 ++++++++++++++--
> > io_uring/uring_cmd.c | 3 ++-
> > security/security.c | 5 +++--
> > security/selinux/hooks.c | 16 +++++++++++++++-
> > 7 files changed, 48 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> > index f94b05c585cb..275826fe3c9e 100644
> > --- a/drivers/nvme/host/core.c
> > +++ b/drivers/nvme/host/core.c
> > @@ -4,6 +4,7 @@
> > * Copyright (c) 2011-2014, Intel Corporation.
> > */
> >
> > +#include "linux/security.h"
> > #include <linux/blkdev.h>
> > #include <linux/blk-mq.h>
> > #include <linux/blk-integrity.h>
> > @@ -3308,6 +3309,13 @@ static int nvme_dev_release(struct inode *inode, struct file *file)
> > return 0;
> > }
> >
> > +int nvme_uring_cmd_sec(struct io_uring_cmd *ioucmd, struct security_uring_cmd *sec)
> > +{
> > + sec->flags = 0;
> > + sec->flags = SECURITY_URING_CMD_TYPE_IOCTL;
> > + return 0;
> > +}
> > +
> > static const struct file_operations nvme_dev_fops = {
> > .owner = THIS_MODULE,
> > .open = nvme_dev_open,
> > @@ -3315,6 +3323,7 @@ static const struct file_operations nvme_dev_fops = {
> > .unlocked_ioctl = nvme_dev_ioctl,
> > .compat_ioctl = compat_ptr_ioctl,
> > .uring_cmd = nvme_dev_uring_cmd,
> > + .uring_cmd_sec = nvme_uring_cmd_sec,
> > };
> >
> > static ssize_t nvme_sysfs_reset(struct device *dev,
> > @@ -3982,6 +3991,7 @@ static const struct file_operations nvme_ns_chr_fops = {
> > .compat_ioctl = compat_ptr_ioctl,
> > .uring_cmd = nvme_ns_chr_uring_cmd,
> > .uring_cmd_iopoll = nvme_ns_chr_uring_cmd_iopoll,
> > + .uring_cmd_sec = nvme_uring_cmd_sec,
> > };
> >
> > static int nvme_add_ns_cdev(struct nvme_ns *ns)
> > diff --git a/include/linux/fs.h b/include/linux/fs.h
> > index e654435f1651..af743a2dd562 100644
> > --- a/include/linux/fs.h
> > +++ b/include/linux/fs.h
> > @@ -2091,6 +2091,7 @@ struct dir_context {
> >
> > struct iov_iter;
> > struct io_uring_cmd;
> > +struct security_uring_cmd;
> >
> > struct file_operations {
> > struct module *owner;
> > @@ -2136,6 +2137,7 @@ struct file_operations {
> > int (*uring_cmd)(struct io_uring_cmd *ioucmd, unsigned int issue_flags);
> > int (*uring_cmd_iopoll)(struct io_uring_cmd *, struct io_comp_batch *,
> > unsigned int poll_flags);
> > + int (*uring_cmd_sec)(struct io_uring_cmd *ioucmd, struct security_uring_cmd*);
> > } __randomize_layout;
> >
> > struct inode_operations {
> > diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
> > index ec119da1d89b..6cef29bce373 100644
> > --- a/include/linux/lsm_hook_defs.h
> > +++ b/include/linux/lsm_hook_defs.h
> > @@ -408,5 +408,6 @@ LSM_HOOK(int, 0, perf_event_write, struct perf_event *event)
> > #ifdef CONFIG_IO_URING
> > LSM_HOOK(int, 0, uring_override_creds, const struct cred *new)
> > LSM_HOOK(int, 0, uring_sqpoll, void)
> > -LSM_HOOK(int, 0, uring_cmd, struct io_uring_cmd *ioucmd)
> > +LSM_HOOK(int, 0, uring_cmd, struct io_uring_cmd *ioucmd,
> > + int (*uring_cmd_sec)(struct io_uring_cmd *ioucmd, struct security_uring_cmd*))
>
> I'm slow, and I'm sure the question has been covered elsewhere,
> but I have real trouble understanding why you're sending a function
> to fetch the security data rather than the data itself. Callbacks
> are not usual for LSM interfaces. If multiple security modules have
> uring_cmd hooks (e.g. SELinux and landlock) the callback has to be
> called multiple times.
No particular reason to have a callback, its just how it came out
initially. I think changing this to a LSM struct is not a deal breaker
for me. Especially if the callback might be called several times
unnecessarily.
TBH, I was expecting more pushback from including it in the file
opeartions struct directly. Do you see any issue with including LSM
specific pointers in the file opeartions?
>
> > #endif /* CONFIG_IO_URING */
> > diff --git a/include/linux/security.h b/include/linux/security.h
> > index ca1b7109c0db..146b1bbdc2e0 100644
> > --- a/include/linux/security.h
> > +++ b/include/linux/security.h
> > @@ -2065,10 +2065,20 @@ static inline int security_perf_event_write(struct perf_event *event)
> > #endif /* CONFIG_PERF_EVENTS */
> >
> > #ifdef CONFIG_IO_URING
> > +enum security_uring_cmd_type
> > +{
> > + SECURITY_URING_CMD_TYPE_IOCTL,
> > +};
> > +
> > +struct security_uring_cmd {
> > + u64 flags;
> > +};
> > #ifdef CONFIG_SECURITY
> > extern int security_uring_override_creds(const struct cred *new);
> > extern int security_uring_sqpoll(void);
> > -extern int security_uring_cmd(struct io_uring_cmd *ioucmd);
> > +extern int security_uring_cmd(struct io_uring_cmd *ioucmd,
> > + int (*uring_cmd_sec)(struct io_uring_cmd *,
> > + struct security_uring_cmd*));
> > #else
> > static inline int security_uring_override_creds(const struct cred *new)
> > {
> > @@ -2078,7 +2088,9 @@ static inline int security_uring_sqpoll(void)
> > {
> > return 0;
> > }
> > -static inline int security_uring_cmd(struct io_uring_cmd *ioucmd)
> > +static inline int security_uring_cmd(struct io_uring_cmd *ioucmd,
> > + int (*uring_cmd_sec)(struct io_uring_cmd *,
> > + struct security_uring_cmd*))
> > {
> > return 0;
> > }
> > diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c
> > index e50de0b6b9f8..2f650b346756 100644
> > --- a/io_uring/uring_cmd.c
> > +++ b/io_uring/uring_cmd.c
> > @@ -108,10 +108,11 @@ int io_uring_cmd(struct io_kiocb *req, unsigned int issue_flags)
> > struct file *file = req->file;
> > int ret;
> >
> > + //req->file->f_op->owner->ei_funcs
> > if (!req->file->f_op->uring_cmd)
> > return -EOPNOTSUPP;
> >
> > - ret = security_uring_cmd(ioucmd);
> > + ret = security_uring_cmd(ioucmd, req->file->f_op->uring_cmd_sec);
> > if (ret)
> > return ret;
> >
> > diff --git a/security/security.c b/security/security.c
> > index 79d82cb6e469..d3360a32f971 100644
> > --- a/security/security.c
> > +++ b/security/security.c
> > @@ -2667,8 +2667,9 @@ int security_uring_sqpoll(void)
> > {
> > return call_int_hook(uring_sqpoll, 0);
> > }
> > -int security_uring_cmd(struct io_uring_cmd *ioucmd)
> > +int security_uring_cmd(struct io_uring_cmd *ioucmd,
> > + int (*uring_cmd_sec)(struct io_uring_cmd *ioucmd, struct security_uring_cmd*))
> > {
> > - return call_int_hook(uring_cmd, 0, ioucmd);
> > + return call_int_hook(uring_cmd, 0, ioucmd, uring_cmd_sec);
> > }
> > #endif /* CONFIG_IO_URING */
> > diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
> > index f553c370397e..9fe3a230c671 100644
> > --- a/security/selinux/hooks.c
> > +++ b/security/selinux/hooks.c
> > @@ -21,6 +21,8 @@
> > * Copyright (C) 2016 Mellanox Technologies
> > */
> >
> > +#include "linux/nvme_ioctl.h"
> > +#include "linux/security.h"
> > #include <linux/init.h>
> > #include <linux/kd.h>
> > #include <linux/kernel.h>
> > @@ -6999,18 +7001,30 @@ static int selinux_uring_sqpoll(void)
> > * IORING_OP_URING_CMD against the device/file specified in @ioucmd.
> > *
> > */
> > -static int selinux_uring_cmd(struct io_uring_cmd *ioucmd)
> > +static int selinux_uring_cmd(struct io_uring_cmd *ioucmd,
> > + int (*uring_cmd_sec)(struct io_uring_cmd *ioucmd, struct security_uring_cmd*))
> > {
> > struct file *file = ioucmd->file;
> > struct inode *inode = file_inode(file);
> > struct inode_security_struct *isec = selinux_inode(inode);
> > struct common_audit_data ad;
> > + const struct cred *cred = current_cred();
> > + struct security_uring_cmd sec_uring = {0};
> > + int ret;
> >
> > ad.type = LSM_AUDIT_DATA_FILE;
> > ad.u.file = file;
> >
> > + ret = uring_cmd_sec(ioucmd, &sec_uring);
> > + if (ret)
> > + return ret;
> > +
> > + if (sec_uring.flags & SECURITY_URING_CMD_TYPE_IOCTL)
> > + return ioctl_has_perm(cred, file, FILE__IOCTL, (u16) ioucmd->cmd_op);
> > +
> > return avc_has_perm(&selinux_state, current_sid(), isec->sid,
> > SECCLASS_IO_URING, IO_URING__CMD, &ad);
> > +
> > }
> > #endif /* CONFIG_IO_URING */
> >
Attachment:
signature.asc
Description: PGP signature
