diff options
| author | Will Drewry <wad@chromium.org> | 2012-02-15 20:45:54 -0600 |
|---|---|---|
| committer | John Rigby <john.rigby@linaro.org> | 2012-06-25 12:17:11 -0600 |
| commit | 16833f40491ba1905a9da786418c7fd127e9238e (patch) | |
| tree | ab7bee48fa96316ea8cb5d618c9f751c4ebd9b0a /arch | |
| parent | 6314ac420d42701368474a76de0901533e803fa0 (diff) | |
UBUNTU: SAUCE: SECCOMP: seccomp: add SECCOMP_RET_ERRNO
This change adds the SECCOMP_RET_ERRNO as a valid return value from a
seccomp filter. Additionally, it makes the first use of the lower
16-bits for storing a filter-supplied errno. 16-bits is more than
enough for the errno-base.h calls.
Returning errors instead of immediately terminating processes that
violate seccomp policy allow for broader use of this functionality
for kernel attack surface reduction. For example, a linux container
could maintain a whitelist of pre-existing system calls but drop
all new ones with errnos. This would keep a logically static attack
surface while providing errnos that may allow for graceful failure
without the downside of do_exit() on a bad call.
v15: - use audit_seccomp and add a skip label. (eparis@redhat.com)
- clean up and pad out return codes (indan@nul.nu)
v14: - no change/rebase
v13: - rebase on to 88ebdda6159ffc15699f204c33feb3e431bf9bdc
v12: - move to WARN_ON if filter is NULL
(oleg@redhat.com, luto@mit.edu, keescook@chromium.org)
- return immediately for filter==NULL (keescook@chromium.org)
- change evaluation to only compare the ACTION so that layered
errnos don't result in the lowest one being returned.
(keeschook@chromium.org)
v11: - check for NULL filter (keescook@chromium.org)
v10: - change loaders to fn
v9: - n/a
v8: - update Kconfig to note new need for syscall_set_return_value.
- reordered such that TRAP behavior follows on later.
- made the for loop a little less indent-y
v7: - introduced
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Will Drewry <wad@chromium.org>
Signed-off-by: Kees Cook <kees@ubuntu.com>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/Kconfig | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/Kconfig b/arch/Kconfig index 91c2c730fc1..139bf64a01f 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -220,8 +220,10 @@ config HAVE_ARCH_SECCOMP_FILTER bool help This symbol should be selected by an architecure if it provides - asm/syscall.h, specifically syscall_get_arguments() and - syscall_get_arch(). + asm/syscall.h, specifically syscall_get_arguments(), + syscall_get_arch(), and syscall_set_return_value(). Additionally, + its system call entry path must respect a return value of -1 from + __secure_computing_int() and/or secure_computing(). config SECCOMP_FILTER def_bool y |