Seccomp ptrace. PTRACE_SECCOMP_GET_FILTER (since Linux 4.

Seccomp ptrace A tracer will be notified if it requests PTRACE_O_TRACESECCOM``P using ``ptrace(PTRACE_SETOPTIONS). 4, the ptrace(2) PTRACE_SECCOMP_GET_FILTER operation can be used to dump a process's seccomp Dec 7, 2017 · docker run --cap-add=SYS_PTRACE --security-opt seccomp=unconfined --security-opt apparmor=unconfined. 本文为看雪论坛优秀文章看雪论坛作者ID：王麻子本人目前绝大部分app都会频繁的使用syscall去获取设备指纹和做一些反调试，使用常规方式过反调试已经非常困难了，使用内存搜索svc指令已经不能满足需求了，开始学习 You signed in with another tab or window. The tracer can skip the system call by changing the syscall number to -1. You switched accounts on another tab or window. I’ll skip the reversing part since it was pretty straight forward. On Linux, you should be able to achieve your goal with seccomp: The tracer will be notified of a PTRACE_EVENT_SECCOMP and the SECCOMP_RET_DATA portion of the BPF program return value will be available to the tracer via PTRACE_GETEVENTMSG. May 12, 2021 · Seccomp relies on cBPF, not eBPF. Up to using whitelist of system calls to allow and disallow system call is understandable. I am using seccomp filters to restrict system calls made by a process. You can use it to restrict the actions available within the container. In general, if an architecture supports both ptrace_event and seccomp, it will be able to support seccomp filter with minor fixup: SIGSYS support and seccomp return value checking. - ptrace-do/inject-seccomp. Therefore, without --seccomp-bpf, strace mostly uses PTRACE_SYSCALL. For PTRACE_EVENT_SECCOMP, this is the seccomp(2) filter's SECCOMP_RET_DATA associated with the triggered rule. If the tracee calls clone(2) with the CLONE_VFORK flag, PTRACE_EVENT_VFORK will be delivered instead if PTRACE_O_TRACEVFORK is set; otherwise if the tracee calls clone(2) with the exit signal set to SIGCHLD, PTRACE_EVENT_FORK will be delivered if PTRACE_O_TRACE‐FORK is set. Architecture support for seccomp BPF Jan 20, 2025 · Date: Mon, 20 Jan 2025 14:44:59 +0100: From: Oleg Nesterov <> Subject [PATCH 3/4] seccomp: remove the 'sd' argument from __secure_computing() seccomp: provides seccomp type definition libseccomp: provides utility function that wrappers libseccomp; forkexec: fork-exec provides mount, unshare, ptrace, seccomp, capset before exec; memfd: read regular file and creates a sealed memfd for its contents; unixsocket: send / recv oob msg from a unix socket 1 day ago · Move the code that calculates the type of the system call stop out of ptrace_get_syscall_info() into a separate function ptrace_get_syscall_info_op() which is going to be used later A ptrace library for easy syscall injection in Linux. The whole post will be divided into 6 sections: (1) Introduction of syscall. ) PTRACE_CONT Restart Aug 26, 2016 · Theoretically, you could make use of the ptrace entry and exit stops to counteract the calls you don't want -- by swapping in bogus arguments that'll cause the system call to fail or do nothing, or by injecting code that'll counter a previous systemcall, but that seems extremely hacky. Based on a CTF challenge from UMDCTF 2022. May 7, 2019 · This option may not catch clone(2) calls in all cases. I stuck on concept of ptrace events generated by seccomp rules. seccomp() provides a superset of the functionality provided by the prctl(2) PR_SET_SECCOMP operation (which does not support flags). But it looks like your best pick if you're really after syscalls. The most recently installed filter has the index 0. PTRACE_SECCOMP_GET_FILTER (since Linux 4. These policies are defined in your deployment yam The tracer will be notified of a PTRACE_EVENT_SECCOMP and the SECCOMP_RET_DATA portion of the BPF program return value will be available to the tracer via PTRACE_GETEVENTMSG. You can use this feature to restrict your application's access. This will retrieve the seccomp SECCOMP_RET_DATA value, which is a 16-bit field set by the BPF program. Share. Since Linux 4. The seccomp() system call operates on the seccomp state of the calling process. Dec 13, 2022 · PTRACE_CONT是重新启动子进程让子进程继续运行下去。PTRACE_SYSCALL也是启动跟踪的子进程但是它只允许子进程执行一条系统调用后暂停。如果单纯使用ptrace去处理svc才需要使用PTRACE_SYSCALL，我们使用的是seccomp+ptrace，系统调用由seccomp进行过滤。 The tracer will be notified of a PTRACE_EVENT_SECCOMP and the SECCOMP_RET_DATA portion of the BPF program return value will be available to the tracer via PTRACE_GETEVENTMSG. I don't think seccomp on its own can modify the arguments for the syscalls, but if you search a little, you quickly find solutions like this one involving seccomp + ptrace. (4) Advanced ptrace. SCMP_ACT_TRACE(uint16_t msg_num) If the thread is being traced and the tracing process specified the PTRACE_O_TRACESECCOMP option in the call to ptrace(2), the tracing process will be notified, via PTRACE_EVENT_SECCOMP, and the value provided in msg_num can be retrieved using the PTRACE_GETEVENTMSG option. 4) This operation allows the tracer to dump the tracee's classic BPF filters. Improve this answer. (2) Introduction of seccomp. The binary forks before setting up seccomp and reading in shellcode from stdin. – Oct 10, 2024 · Seccomp policies come in three flavors: RuntimeDefault, Localhost, and Unconfined. Oct 1, 2023 · ptrace is a somewhat cross-platform layer that allows you to intercept syscalls in a process. The tracer will be notified of a PTRACE_EVENT_SECCOMP and the SECCOMP_RET_DATA portion of the BPF program return value will be available to the tracer via PTRACE_GETEVENTMSG. (3) Introduction of ptrace. May 11, 2018 · In this post, I will talk about the seccomp and ptrace step by step. Apr 13, 2022 · How to escape a seccomp jail using only ptrace. Mar 8, 2017 · In the conclusions to my last post, “Modifying System Call Arguments With ptrace”, I mentioned that one of the main drawbacks of the explained approach for modifying system call arguments was that there is a process switch for each system call performed by the tracee. addr is an integer specifying the index of the filter to be dumped. Here’s a short writeup on the seccomp jail escape in UMDCTF 2022 (tracestory). May 25, 2024 · 读文档时发现了seccomp的unotify机制，该机制可以把seccomp拦截到的系统调用转发至其他进程处理，并且在执行fork、exec等操作时，seccomp的过滤器会被内核自动拷贝进新进程， 所以在编写初版程序时，便采用了单seccomp的方式，并没有使用ptrace。 seccomp() provides a superset of the functionality provided by the prctl(2) PR_SET_SECCOMP operation (which does not support flags). The manual reference of ptrace [6] is heavily recommended for this topic. These flavors tell the container where to look for the seccomp profile to implement, as well as what policies syscalls will be restricted to the container. Oct 2, 2019 · When the strace process is done decoding and displaying the syscall, it can restart the tracee in the kernel with the PTRACE_CONT command. 总的来说如果一个架构同时支持ptrace_event和 seccomp，那么它将可以通过较小的修改支持seccomp过滤器： SIGSYS 支持和seccomp 返回值检查。 然后必须将 CONFIG_HAVE_ARCH_SECCOMP_FILTER 添加到它的架构特定 的Kconfig中。 seccomp() provides a superset of the functionality provided by the prctl(2) PR_SET_SECCOMP operation (which does not support flags). You can read and modify memory and registers in the process, when the syscalls starts and before it finishes. (addr is ignored. To perform the same action, but stop the tracee at the next syscall entry or exit, the strace process can use PTRACE_SYSCALL. 4, the ptrace(2) PTRACE_SECCOMP_GET_FILTER operation can be used to dump a process's seccomp filters. gdb and strace both use ptrace for their magic. Then it must just add CONFIG_HAVE_ARCH_SECCOMP_FILTER to its arch-specific Kconfig. . Secure computing mode (seccomp) is a Linux kernel feature. c at master · itshacki/ptrace-do seccomp-bpf is an extension to seccomp [8] to improve the runtime and security of the ptrace sandboxing used to sandbox package builds on Exherbo Linux distribution. You signed out in another tab or window. Follow Mar 24, 2017 · When waitpid returns, depending on the contents of status, one can retrieve the seccomp return value using the PTRACE_GETEVENTMSG ptrace operation. Reload to refresh your session. tbfyv vjisd uvbay qneg fblbgnsq pdcyrq imeh semov scbkld zstv