mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-23 05:43:47 +07:00
51891498f2
The restriction introduced in 7a0df7fbc1 ("seccomp: Make NEW_LISTENER and
TSYNC flags exclusive") is mostly artificial: there is enough information
in a seccomp user notification to tell which thread triggered a
notification. The reason it was introduced is because TSYNC makes the
syscall return a thread-id on failure, and NEW_LISTENER returns an fd, and
there's no way to distinguish between these two cases (well, I suppose the
caller could check all fds it has, then do the syscall, and if the return
value was an fd that already existed, then it must be a thread id, but
bleh).
Matthew would like to use these two flags together in the Chrome sandbox
which wants to use TSYNC for video drivers and NEW_LISTENER to proxy
syscalls.
So, let's fix this ugliness by adding another flag, TSYNC_ESRCH, which
tells the kernel to just return -ESRCH on a TSYNC error. This way,
NEW_LISTENER (and any subsequent seccomp() commands that want to return
positive values) don't conflict with each other.
Suggested-by: Matthew Denton <mpdenton@google.com>
Signed-off-by: Tycho Andersen <tycho@tycho.ws>
Link: https://lore.kernel.org/r/20200304180517.23867-1-tycho@tycho.ws
Signed-off-by: Kees Cook <keescook@chromium.org>
117 lines
2.9 KiB
C
117 lines
2.9 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _LINUX_SECCOMP_H
|
|
#define _LINUX_SECCOMP_H
|
|
|
|
#include <uapi/linux/seccomp.h>
|
|
|
|
#define SECCOMP_FILTER_FLAG_MASK (SECCOMP_FILTER_FLAG_TSYNC | \
|
|
SECCOMP_FILTER_FLAG_LOG | \
|
|
SECCOMP_FILTER_FLAG_SPEC_ALLOW | \
|
|
SECCOMP_FILTER_FLAG_NEW_LISTENER | \
|
|
SECCOMP_FILTER_FLAG_TSYNC_ESRCH)
|
|
|
|
#ifdef CONFIG_SECCOMP
|
|
|
|
#include <linux/thread_info.h>
|
|
#include <asm/seccomp.h>
|
|
|
|
struct seccomp_filter;
|
|
/**
|
|
* struct seccomp - the state of a seccomp'ed process
|
|
*
|
|
* @mode: indicates one of the valid values above for controlled
|
|
* system calls available to a process.
|
|
* @filter: must always point to a valid seccomp-filter or NULL as it is
|
|
* accessed without locking during system call entry.
|
|
*
|
|
* @filter must only be accessed from the context of current as there
|
|
* is no read locking.
|
|
*/
|
|
struct seccomp {
|
|
int mode;
|
|
struct seccomp_filter *filter;
|
|
};
|
|
|
|
#ifdef CONFIG_HAVE_ARCH_SECCOMP_FILTER
|
|
extern int __secure_computing(const struct seccomp_data *sd);
|
|
static inline int secure_computing(void)
|
|
{
|
|
if (unlikely(test_thread_flag(TIF_SECCOMP)))
|
|
return __secure_computing(NULL);
|
|
return 0;
|
|
}
|
|
#else
|
|
extern void secure_computing_strict(int this_syscall);
|
|
#endif
|
|
|
|
extern long prctl_get_seccomp(void);
|
|
extern long prctl_set_seccomp(unsigned long, void __user *);
|
|
|
|
static inline int seccomp_mode(struct seccomp *s)
|
|
{
|
|
return s->mode;
|
|
}
|
|
|
|
#else /* CONFIG_SECCOMP */
|
|
|
|
#include <linux/errno.h>
|
|
|
|
struct seccomp { };
|
|
struct seccomp_filter { };
|
|
|
|
#ifdef CONFIG_HAVE_ARCH_SECCOMP_FILTER
|
|
static inline int secure_computing(void) { return 0; }
|
|
#else
|
|
static inline void secure_computing_strict(int this_syscall) { return; }
|
|
#endif
|
|
|
|
static inline long prctl_get_seccomp(void)
|
|
{
|
|
return -EINVAL;
|
|
}
|
|
|
|
static inline long prctl_set_seccomp(unsigned long arg2, char __user *arg3)
|
|
{
|
|
return -EINVAL;
|
|
}
|
|
|
|
static inline int seccomp_mode(struct seccomp *s)
|
|
{
|
|
return SECCOMP_MODE_DISABLED;
|
|
}
|
|
#endif /* CONFIG_SECCOMP */
|
|
|
|
#ifdef CONFIG_SECCOMP_FILTER
|
|
extern void put_seccomp_filter(struct task_struct *tsk);
|
|
extern void get_seccomp_filter(struct task_struct *tsk);
|
|
#else /* CONFIG_SECCOMP_FILTER */
|
|
static inline void put_seccomp_filter(struct task_struct *tsk)
|
|
{
|
|
return;
|
|
}
|
|
static inline void get_seccomp_filter(struct task_struct *tsk)
|
|
{
|
|
return;
|
|
}
|
|
#endif /* CONFIG_SECCOMP_FILTER */
|
|
|
|
#if defined(CONFIG_SECCOMP_FILTER) && defined(CONFIG_CHECKPOINT_RESTORE)
|
|
extern long seccomp_get_filter(struct task_struct *task,
|
|
unsigned long filter_off, void __user *data);
|
|
extern long seccomp_get_metadata(struct task_struct *task,
|
|
unsigned long filter_off, void __user *data);
|
|
#else
|
|
static inline long seccomp_get_filter(struct task_struct *task,
|
|
unsigned long n, void __user *data)
|
|
{
|
|
return -EINVAL;
|
|
}
|
|
static inline long seccomp_get_metadata(struct task_struct *task,
|
|
unsigned long filter_off,
|
|
void __user *data)
|
|
{
|
|
return -EINVAL;
|
|
}
|
|
#endif /* CONFIG_SECCOMP_FILTER && CONFIG_CHECKPOINT_RESTORE */
|
|
#endif /* _LINUX_SECCOMP_H */
|