diff options
| author | Tycho Andersen <tycho@tycho.ws> | 2018-12-09 11:24:12 -0700 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2018-12-11 16:28:41 -0800 |
| commit | a5662e4d81c4d4b08140c625d0f3c50b15786252 (patch) | |
| tree | d21aaa33543bb1c440fa264ba99c0feb36b3536d | |
| parent | db5113911abaa7eb20cf115d4339959c1aecea95 (diff) | |
seccomp: switch system call argument type to void *
The const qualifier causes problems for any code that wants to write to the
third argument of the seccomp syscall, as we will do in a future patch in
this series.
The third argument to the seccomp syscall is documented as void *, so
rather than just dropping the const, let's switch everything to use void *
as well.
I believe this is safe because of 1. the documentation above, 2. there's no
real type information exported about syscalls anywhere besides the man
pages.
Signed-off-by: Tycho Andersen <tycho@tycho.ws>
CC: Kees Cook <keescook@chromium.org>
CC: Andy Lutomirski <luto@amacapital.net>
CC: Oleg Nesterov <oleg@redhat.com>
CC: Eric W. Biederman <ebiederm@xmission.com>
CC: "Serge E. Hallyn" <serge@hallyn.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
CC: Christian Brauner <christian@brauner.io>
CC: Tyler Hicks <tyhicks@canonical.com>
CC: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>
Signed-off-by: Kees Cook <keescook@chromium.org>
| -rw-r--r-- | include/linux/seccomp.h | 2 | ||||
| -rw-r--r-- | include/linux/syscalls.h | 2 | ||||
| -rw-r--r-- | kernel/seccomp.c | 8 |
3 files changed, 6 insertions, 6 deletions
diff --git a/include/linux/seccomp.h b/include/linux/seccomp.h index e5320f6c8654..b5103c019cf4 100644 --- a/include/linux/seccomp.h +++ b/include/linux/seccomp.h @@ -43,7 +43,7 @@ extern void secure_computing_strict(int this_syscall); #endif extern long prctl_get_seccomp(void); -extern long prctl_set_seccomp(unsigned long, char __user *); +extern long prctl_set_seccomp(unsigned long, void __user *); static inline int seccomp_mode(struct seccomp *s) { diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 2ac3d13a915b..a60694fb0f58 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -879,7 +879,7 @@ asmlinkage long sys_renameat2(int olddfd, const char __user *oldname, int newdfd, const char __user *newname, unsigned int flags); asmlinkage long sys_seccomp(unsigned int op, unsigned int flags, - const char __user *uargs); + void __user *uargs); asmlinkage long sys_getrandom(char __user *buf, size_t count, unsigned int flags); asmlinkage long sys_memfd_create(const char __user *uname_ptr, unsigned int flags); diff --git a/kernel/seccomp.c b/kernel/seccomp.c index 96afc32e041d..393e029f778a 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -924,7 +924,7 @@ static long seccomp_get_action_avail(const char __user *uaction) /* Common entry point for both prctl and syscall. */ static long do_seccomp(unsigned int op, unsigned int flags, - const char __user *uargs) + void __user *uargs) { switch (op) { case SECCOMP_SET_MODE_STRICT: @@ -944,7 +944,7 @@ static long do_seccomp(unsigned int op, unsigned int flags, } SYSCALL_DEFINE3(seccomp, unsigned int, op, unsigned int, flags, - const char __user *, uargs) + void __user *, uargs) { return do_seccomp(op, flags, uargs); } @@ -956,10 +956,10 @@ SYSCALL_DEFINE3(seccomp, unsigned int, op, unsigned int, flags, * * Returns 0 on success or -EINVAL on failure. */ -long prctl_set_seccomp(unsigned long seccomp_mode, char __user *filter) +long prctl_set_seccomp(unsigned long seccomp_mode, void __user *filter) { unsigned int op; - char __user *uargs; + void __user *uargs; switch (seccomp_mode) { case SECCOMP_MODE_STRICT: |