[RFC PATCH 2/2] capability: use new capable_or functionality

Christian Göttsche
2022-02-17T14:50:42Z

Use the new added capable_or macro in appropriate cases, where a task
is required to have any of two capabilities.

Reorder CAP_SYS_ADMIN last.

TODO: split into subsystem patches.

Fixes: 94c4b4fd25e6 ("block: Check ADMIN before NICE for IOPRIO_CLASS_RT")

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
---
block/ioprio.c | 9 +--------
drivers/media/common/saa7146/saa7146_video.c | 2 +-
drivers/media/pci/bt8xx/bttv-driver.c | 3 +--
drivers/media/pci/saa7134/saa7134-video.c | 3 +--
drivers/media/platform/fsl-viu.c | 2 +-
drivers/media/test-drivers/vivid/vivid-vid-cap.c | 2 +-
drivers/net/caif/caif_serial.c | 2 +-
drivers/s390/block/dasd_eckd.c | 2 +-
fs/pipe.c | 2 +-
include/linux/capability.h | 4 ++--
kernel/bpf/syscall.c | 2 +-
kernel/fork.c | 2 +-
kernel/sys.c | 2 +-
net/caif/caif_socket.c | 2 +-
net/unix/scm.c | 2 +-
15 files changed, 16 insertions(+), 25 deletions(-)

diff --git a/block/ioprio.c b/block/ioprio.c
index 2fe068fcaad5..52d5da286323 100644
--- a/block/ioprio.c
+++ b/block/ioprio.c
@@ -37,14 +37,7 @@ int ioprio_check_cap(int ioprio)

switch (class) {
case IOPRIO_CLASS_RT:
- /*
- * Originally this only checked for CAP_SYS_ADMIN,
- * which was implicitly allowed for pid 0 by security
- * modules such as SELinux. Make sure we check
- * CAP_SYS_ADMIN first to avoid a denial/avc for
- * possibly missing CAP_SYS_NICE permission.
- */
- if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_NICE))
+ if (!capable_or(CAP_SYS_NICE, CAP_SYS_ADMIN))
return -EPERM;
fallthrough;
/* rt has prio field too */
diff --git a/drivers/media/common/saa7146/saa7146_video.c b/drivers/media/common/saa7146/saa7146_video.c
index 66215d9106a4..5eabc2e77cc2 100644
--- a/drivers/media/common/saa7146/saa7146_video.c
+++ b/drivers/media/common/saa7146/saa7146_video.c
@@ -470,7 +470,7 @@ static int vidioc_s_fbuf(struct file *file, void *fh, const struct v4l2_framebuf

DEB_EE("VIDIOC_S_FBUF\n");

- if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RAWIO))
+ if (!capable_or(CAP_SYS_RAWIO, CAP_SYS_ADMIN))
return -EPERM;

/* check args */
diff --git a/drivers/media/pci/bt8xx/bttv-driver.c b/drivers/media/pci/bt8xx/bttv-driver.c
index 8cc9bec43688..c2437ff07246 100644
--- a/drivers/media/pci/bt8xx/bttv-driver.c
+++ b/drivers/media/pci/bt8xx/bttv-driver.c
@@ -2569,8 +2569,7 @@ static int bttv_s_fbuf(struct file *file, void *f,
const struct bttv_format *fmt;
int retval;

- if (!capable(CAP_SYS_ADMIN) &&
- !capable(CAP_SYS_RAWIO))
+ if (!capable_or(CAP_SYS_RAWIO, CAP_SYS_ADMIN))
return -EPERM;

/* check args */
diff --git a/drivers/media/pci/saa7134/saa7134-video.c b/drivers/media/pci/saa7134/saa7134-video.c
index 374c8e1087de..356b77c16f87 100644
--- a/drivers/media/pci/saa7134/saa7134-video.c
+++ b/drivers/media/pci/saa7134/saa7134-video.c
@@ -1803,8 +1803,7 @@ static int saa7134_s_fbuf(struct file *file, void *f,
struct saa7134_dev *dev = video_drvdata(file);
struct saa7134_format *fmt;

- if (!capable(CAP_SYS_ADMIN) &&
- !capable(CAP_SYS_RAWIO))
+ if (!capable_or(CAP_SYS_RAWIO, CAP_SYS_ADMIN))
return -EPERM;

/* check args */
diff --git a/drivers/media/platform/fsl-viu.c b/drivers/media/platform/fsl-viu.c
index a4bfa70b49b2..925c34c2b1b3 100644
--- a/drivers/media/platform/fsl-viu.c
+++ b/drivers/media/platform/fsl-viu.c
@@ -803,7 +803,7 @@ static int vidioc_s_fbuf(struct file *file, void *priv, const struct v4l2_frameb
const struct v4l2_framebuffer *fb = arg;
struct viu_fmt *fmt;

- if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RAWIO))
+ if (!capable_or(CAP_SYS_RAWIO, CAP_SYS_ADMIN))
return -EPERM;

/* check args */
diff --git a/drivers/media/test-drivers/vivid/vivid-vid-cap.c b/drivers/media/test-drivers/vivid/vivid-vid-cap.c
index b9caa4b26209..a0cfcf6c22c4 100644
--- a/drivers/media/test-drivers/vivid/vivid-vid-cap.c
+++ b/drivers/media/test-drivers/vivid/vivid-vid-cap.c
@@ -1253,7 +1253,7 @@ int vivid_vid_cap_s_fbuf(struct file *file, void *fh,
if (dev->multiplanar)
return -ENOTTY;

- if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RAWIO))
+ if (!capable_or(CAP_SYS_RAWIO, CAP_SYS_ADMIN))
return -EPERM;

if (dev->overlay_cap_owner)
diff --git a/drivers/net/caif/caif_serial.c b/drivers/net/caif/caif_serial.c
index 2a7af611d43a..245c30c469c2 100644
--- a/drivers/net/caif/caif_serial.c
+++ b/drivers/net/caif/caif_serial.c
@@ -326,7 +326,7 @@ static int ldisc_open(struct tty_struct *tty)
/* No write no play */
if (tty->ops->write == NULL)
return -EOPNOTSUPP;
- if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_TTY_CONFIG))
+ if (!capable_or(CAP_SYS_TTY_CONFIG, CAP_SYS_ADMIN))
return -EPERM;

/* release devices to avoid name collision */
diff --git a/drivers/s390/block/dasd_eckd.c b/drivers/s390/block/dasd_eckd.c
index 8410a25a65c1..9b5d22dd3e7b 100644
--- a/drivers/s390/block/dasd_eckd.c
+++ b/drivers/s390/block/dasd_eckd.c
@@ -5319,7 +5319,7 @@ static int dasd_symm_io(struct dasd_device *device, void __user *argp)
char psf0, psf1;
int rc;

- if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RAWIO))
+ if (!capable_or(CAP_SYS_RAWIO, CAP_SYS_ADMIN))
return -EACCES;
psf0 = psf1 = 0;

diff --git a/fs/pipe.c b/fs/pipe.c
index cc28623a67b6..47dc9b59b7a5 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -775,7 +775,7 @@ bool too_many_pipe_buffers_hard(unsigned long user_bufs)

bool pipe_is_unprivileged_user(void)
{
- return !capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN);
+ return !capable_or(CAP_SYS_RESOURCE, CAP_SYS_ADMIN);
}

struct pipe_inode_info *alloc_pipe_info(void)
diff --git a/include/linux/capability.h b/include/linux/capability.h
index 5c55687a9a05..5ed55b73cb62 100644
--- a/include/linux/capability.h
+++ b/include/linux/capability.h
@@ -262,12 +262,12 @@ extern bool file_ns_capable(const struct file *file, struct user_namespace *ns,
extern bool ptracer_capable(struct task_struct *tsk, struct user_namespace *ns);
static inline bool perfmon_capable(void)
{
- return capable(CAP_PERFMON) || capable(CAP_SYS_ADMIN);
+ return capable_or(CAP_PERFMON, CAP_SYS_ADMIN);
}

static inline bool bpf_capable(void)
{
- return capable(CAP_BPF) || capable(CAP_SYS_ADMIN);
+ return capable_or(CAP_BPF, CAP_SYS_ADMIN);
}

static inline bool checkpoint_restore_ns_capable(struct user_namespace *ns)
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index fa4505f9b611..108dd09f978a 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -2243,7 +2243,7 @@ static int bpf_prog_load(union bpf_attr *attr, bpfptr_t uattr)
!bpf_capable())
return -EPERM;

- if (is_net_admin_prog_type(type) && !capable(CAP_NET_ADMIN) && !capable(CAP_SYS_ADMIN))
+ if (is_net_admin_prog_type(type) && !capable_or(CAP_NET_ADMIN, CAP_SYS_ADMIN))
return -EPERM;
if (is_perfmon_prog_type(type) && !perfmon_capable())
return -EPERM;
diff --git a/kernel/fork.c b/kernel/fork.c
index d75a528f7b21..067702f2eb15 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -2024,7 +2024,7 @@ static __latent_entropy struct task_struct *copy_process(
retval = -EAGAIN;
if (is_ucounts_overlimit(task_ucounts(p), UCOUNT_RLIMIT_NPROC, rlimit(RLIMIT_NPROC))) {
if (p->real_cred->user != INIT_USER &&
- !capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN))
+ !capable_or(CAP_SYS_RESOURCE, CAP_SYS_ADMIN))
goto bad_fork_free;
}
current->flags &= ~PF_NPROC_EXCEEDED;
diff --git a/kernel/sys.c b/kernel/sys.c
index ecc4cf019242..9df6c5e77620 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -481,7 +481,7 @@ static int set_user(struct cred *new)
*/
if (is_ucounts_overlimit(new->ucounts, UCOUNT_RLIMIT_NPROC, rlimit(RLIMIT_NPROC)) &&
new_user != INIT_USER &&
- !capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN))
+ !capable_or(CAP_SYS_RESOURCE, CAP_SYS_ADMIN))
current->flags |= PF_NPROC_EXCEEDED;
else
current->flags &= ~PF_NPROC_EXCEEDED;
diff --git a/net/caif/caif_socket.c b/net/caif/caif_socket.c
index 2b8892d502f7..60498148126c 100644
--- a/net/caif/caif_socket.c
+++ b/net/caif/caif_socket.c
@@ -1036,7 +1036,7 @@ static int caif_create(struct net *net, struct socket *sock, int protocol,
.usersize = sizeof_field(struct caifsock, conn_req.param)
};

- if (!capable(CAP_SYS_ADMIN) && !capable(CAP_NET_ADMIN))
+ if (!capable_or(CAP_NET_ADMIN, CAP_SYS_ADMIN))
return -EPERM;
/*
* The sock->type specifies the socket type to use.
diff --git a/net/unix/scm.c b/net/unix/scm.c
index aa27a02478dc..821be80e6c85 100644
--- a/net/unix/scm.c
+++ b/net/unix/scm.c
@@ -99,7 +99,7 @@ static inline bool too_many_unix_fds(struct task_struct *p)
struct user_struct *user = current_user();

if (unlikely(user->unix_inflight > task_rlimit(p, RLIMIT_NOFILE)))
- return !capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN);
+ return !capable_or(CAP_SYS_RESOURCE, CAP_SYS_ADMIN);
return false;
}

--
2.35.1